Isiokwu a bụ akụkụ nke isiokwu nyocha ahụ bụ "Teknụzụ bioremediation dị elu na usoro imegharị ihe ndị mejupụtara ihe ndị dị ndụ (SOC)". Lee edemede iri na anọ niile.
A na-eji obere polycyclic aromatic hydrocarbons (PAHs) dị ka naphthalene na naphthalenes ndị a gbanwere (methylnaphthalene, naphthoic acid, 1-naphthyl-N-methylcarbamate, wdg) eme ihe n'ọtụtụ ụlọ ọrụ dị iche iche ma bụrụ ihe na-egbu egbu, na-emebi emebi na/ma ọ bụ na-akpata kansa nye ihe ndị dị ndụ. A na-ewere ngwakọta organic ndị a (SOCs) ma ọ bụ xenobiotics dị ka ihe kacha mkpa na-emerụ ahụ ma na-etinye nnukwu ihe egwu nye gburugburu ebe obibi na ahụike ọha na eze. Ike nke ọrụ mmadụ (dịka ọmụmaatụ gasification coal, nchacha mmanụ, mwepụta ụgbọala na ngwa ọrụ ugbo) na-ekpebi mkpokọta, akara aka na njem nke ihe ndị a niile na-adịgide adịgide. Na mgbakwunye na usoro ọgwụgwọ/iwepụ anụ ahụ na kemịkalụ, teknụzụ akwụkwọ ndụ akwụkwọ ndụ na nke na-adịghị emebi gburugburu ebe obibi dị ka bioremediation, nke na-eji obere nje nwere ike imebi POC kpamkpam ma ọ bụ ịtụgharị ha ka ha bụrụ ngwaahịa na-adịghị egbu egbu, apụtala dị ka ihe ọzọ dị nchebe, dị ọnụ ala ma na-ekwe nkwa. Ụdị nje bacteria dị iche iche nke phyla Proteobacteria (Pseudomonas, Pseudomonas, Comamonas, Burkholderia, na Neosphingobacterium), Firmicutes (Bacillus na Paenibacillus), na Actinobacteria (Rhodococcus na Arthrobacter) n'ime ala egosila ikike imebi ọtụtụ ihe ndị dị ndụ. Ọmụmụ ihe gbasara metabolism, genomics, na nyocha metagenomic na-enyere anyị aka ịghọta mgbagwoju anya na ụdị dị iche iche dị na ụdị ndụ dị mfe ndị a, nke enwere ike itinye n'ọrụ maka mmebi biodegradation dị irè. Ogologo oge nke PAHs emeela ka a mata ụdị mbibi ọhụrụ site na nnyefe mkpụrụ ndụ ihe nketa kwụ ọtọ site na iji ihe mkpụrụ ndụ ihe nketa dị ka plasmids, transposons, bacteriophages, genomic Islands, na ihe ndị jikọtara ọnụ. Bayọlọji sistemụ na injinịa mkpụrụ ndụ ihe nketa nke ndị dịpụrụ adịpụ ma ọ bụ obodo nlereanya (consortia) nwere ike ime ka biorediation zuru oke, ngwa ngwa na nke ọma nke PAH ndị a site na mmetụta synergistic. N'ime nyocha a, anyị na-elekwasị anya n'ụzọ dị iche iche nke metabolic na ụdị dị iche iche, ihe mejupụtara mkpụrụ ndụ ihe nketa na ụdị dị iche iche, na nzaghachi/mmegharị nke sel nke naphthalene na nje bacteria na-emebi ihe naphthalene dochie anya. Nke a ga-enye ozi gbasara gburugburu ebe obibi maka itinye n'ọrụ ubi na imeziwanye nrụgide maka ọgwụgwọ bioredition dị irè.
Mmepe ngwa ngwa nke ụlọ ọrụ (petrochemicals, ọrụ ugbo, ọgwụ, agba ákwà, ihe ịchọ mma, wdg) enyela aka n'ọganihu akụ na ụba ụwa na mmụba nke ụkpụrụ ibi ndụ. Mmepe a na-eme ka e nwee ọtụtụ ihe ndị e ji emepụta ihe ndị sitere n'okike (SOCs), nke a na-eji emepụta ngwaahịa dị iche iche. Ihe ndị a ma ọ bụ SOCs ndị si mba ọzọ gụnyere polycyclic aromatic hydrocarbons (PAHs), pesticides, herbicides, plasticizers, colors, pharmaceuticals, organophosphates, flammatants, retardants organic solvents, wdg. A na-ewepụta ha n'ime ikuku, gburugburu ebe obibi mmiri na nke ụwa ebe ha nwere mmetụta dị iche iche, na-akpata mmetụta ọjọọ na ụdị bioforms dị iche iche site na mgbanwe nke ihe onwunwe physicochemical na nhazi obodo (Petrie et al., 2015; Bernhardt et al., 2017; Sarkar et al., 2020). Ọtụtụ ihe ndị na-eme ka ihe dị nro na-esi ísì ụtọ nwere mmetụta siri ike ma na-ebibi ihe n'ọtụtụ ebe obibi/ebe dị iche iche dị ndụ na-adịghị emebi emebi (dịka ọmụmaatụ coral reefs, Arctic/Antarctic ice sheets, elu ugwu ọdọ mmiri, sedimenti miri emi nke oké osimiri, wdg.) (Jones 2010; Beyer et al. 2020; Nordborg et al. 2020). Ọmụmụ geomicrobiological na-adịbeghị anya egosila na itinye ihe ndị sitere n'okike (dịka ihe ndị na-eme ka ihe dị nro na-esi ísì ụtọ) na ihe ndị sitere na ha n'elu ihe owuwu e ji aka rụọ (ebe e wuru) (dịka ebe ihe nketa omenala na ihe ncheta e ji granite, nkume, osisi na ígwè mee) na-eme ka mmebi ha dịkwuo ngwa ngwa (Gadd 2017; Liu et al. 2018). Ọrụ mmadụ nwere ike ime ka mmebi ihe ndị dị ndụ nke ihe ncheta na ụlọ dịkwuo njọ site na mmetọ ikuku na mgbanwe ihu igwe (Liu et al. 2020). Ihe ndị a na-eme ka ihe ndị dị ndụ na-emeghachi omume na uzuoku mmiri n'ikuku ma na-adakwasị n'elu ihe owuwu ahụ, na-akpata mmebi anụ ahụ na nke kemịkalụ nke ihe ahụ. A maara nke ọma na mmebi ihe dị ndụ bụ mgbanwe na-adịghị mma n'ọdịdị na àgwà nke ihe ndị dị ndụ na-akpata nke na-emetụta nchekwa ha (Pochon na Jaton, 1967). Mmega ahụ nje bacteria (metabolism) nke ihe ndị a nwere ike ibelata iguzosi ike n'ezi ihe owuwu, irè nchekwa na uru omenala (Gadd, 2017; Liu et al., 2018). N'aka nke ọzọ, n'ọnọdụ ụfọdụ, a chọpụtala na mgbanwe nje bacteria na nzaghachi nye ihe ndị a bara uru ka ha na-emepụta biofilms na ihe nchebe ndị ọzọ na-ebelata ọnụego ire ere/ire ere (Martino, 2016). Ya mere, mmepe nke atụmatụ nchekwa ogologo oge dị irè maka ihe ncheta nkume, ígwè na osisi chọrọ nghọta zuru oke nke usoro ndị dị mkpa dị na usoro a. Ma e jiri ya tụnyere usoro okike (usoro ala, ọkụ ọhịa, mgbawa ugwu mgbawa, mmeghachi omume osisi na nje bacteria), ihe omume mmadụ na-eme ka mwepụta nke nnukwu nnukwu hydrocarbons polycyclic aromatic (PAHs) na carbon organic ndị ọzọ (OC) banye na gburugburu ebe obibi. Ọtụtụ PAH eji arụ ọrụ ugbo (ọgwụ ahụhụ na ọgwụ ahụhụ dịka DDT, atrazine, carbaryl, pentachlorophenol, wdg), ụlọ ọrụ (mmanụ dị nro, nsị mmanụ/ihe mkpofu, plastik sitere na mmanụ ala, PCBs, plastik, ihe nhicha, ihe na-egbu nje, ihe na-esi ísì ụtọ, ihe na-esi ísì ụtọ na ihe nchekwa), ngwaahịa nlekọta onwe onye (ihe mkpuchi anyanwụ, ihe na-egbu nje, ihe na-egbu nje na musk polycyclic) na ngwa agha (ihe mgbawa dị ka 2,4,6-TNT) bụ ihe nwere ike imetụta ahụike ụwa (Srogi, 2007; Vamsee-Krishna na Phale, 2008; Petrie et al., 2015). Enwere ike ịgbasa ndepụta a iji gụnye ihe ndị sitere na mmanụ ala (mmanụ mmanụ, mmanụ ọkụ, asfaltenes), bioplastics dị elu, na mmiri ionic (Amde et al., 2015). Tebụl 1 depụtara ọtụtụ ihe na-eme ka ihe na-esi ísì ụtọ na ngwa ha na ụlọ ọrụ dị iche iche. N'afọ ndị na-adịbeghị anya, mwepụta nke ihe ndị na-emepụta ihe ndị na-agbanwe agbanwe, yana carbon dioxide na gas ndị ọzọ na-emepụta ihe ọkụkụ, amalitela ịbawanye (Dvorak et al., 2017). Agbanyeghị, mmetụta nke ihe ndị na-emepụta ihe ndị na-emepụta ihe karịrị nke eke. Na mgbakwunye, anyị chọpụtara na ọtụtụ SOCs ka na-adịgide n'ọtụtụ gburugburu ebe obibi ma achọpụtala ha dị ka ihe ndị na-emepụta ihe ndị na-apụta ìhè nke nwere mmetụta ọjọọ na biomes (Foto 1). Ụlọ ọrụ gburugburu ebe obibi dịka United States Environmental Protection Agency (USEPA) etinyela ọtụtụ n'ime ihe ndị a na ndepụta ha kacha mkpa n'ihi ihe ndị na-egbu egbu, genotoxic, mutagenic, na carcinogenic. Ya mere, iwu mkpofu siri ike na atụmatụ dị irè maka ọgwụgwọ/iwepụ ihe mkpofu site na gburugburu ebe obibi ndị ruru unyi dị mkpa. Ụzọ ọgwụgwọ anụ ahụ na kemịkal dị iche iche dịka pyrolysis, ọgwụgwọ okpomọkụ oxidative, ikuku ikuku, ijupụta ihe mkpofu, ịgba ọkụ, wdg adịghị arụ ọrụ ma dị oke ọnụ ma na-emepụta ihe na-emebi emebi, na-egbu egbu ma sie ike ịgwọ ihe ndị sitere na ngwaahịa. Ka a na-amatakwu ihe gbasara gburugburu ebe obibi n'ụwa niile, ụmụ nje ndị nwere ike imebi ihe ndị a na ihe ndị sitere na ha (dịka halogenated, nitro, alkyl na/ma ọ bụ methyl) na-adọta mmasị na-arịwanye elu (Fennell et al., 2004; Haritash na Kaushik, 2009; Phale et al., 2020; Sarkar et al., 2020; Schwanemann et al., 2020). Ojiji nke ụmụ nje ndị a naanị ma ọ bụ na omenala dị iche iche (colonies) maka iwepụ ihe ndị na-emerụ ahụ na-esi ísì ụtọ nwere uru n'ihe gbasara nchekwa gburugburu ebe obibi, ọnụ ahịa, arụmọrụ, irè, na nkwado. Ndị nchọpụta na-enyochakwa njikọta nke usoro nje na usoro redox electrochemical, ya bụ sistemụ bioelectrochemical (BES), dị ka teknụzụ na-ekwe nkwa maka ọgwụgwọ/iwepụ ihe ndị na-emerụ emerụ (Huang et al., 2011). Teknụzụ BES adọtala mmasị na-abawanye ụba n'ihi arụmọrụ dị elu ya, ọnụ ahịa dị ala, nchekwa gburugburu ebe obibi, ọrụ okpomọkụ ụlọ, ihe ndị na-adabara ihe ndị dị ndụ, na ikike iweghachite ngwaahịa bara uru (dịka ọmụmaatụ, ọkụ eletrik, mmanụ ọkụ, na kemịkalụ) (Pant et al., 2012; Nazari et al., 2020). Mmalite nke usoro genome dị elu na ngwaọrụ/ụzọ omics enyela ọtụtụ ozi ọhụrụ gbasara nhazi mkpụrụ ndụ ihe nketa, proteomics, na fluxomics nke mmeghachi omume nke microorganisms dị iche iche na-emebi emebi. Ijikọta ngwaọrụ ndị a na bayoloji sistemụ emeela ka nghọta anyị dịkwuo mma banyere nhọrọ na nhazi nke ụzọ catabolic lekwasịrị anya na microorganisms (ya bụ, imewe metabolic) iji nweta biodegradation dị irè na nke dị irè. Iji chepụta atụmatụ bioremediation dị irè site na iji microorganisms kwesịrị ekwesị, anyị kwesịrị ịghọta ikike biochemical, ụdị metabolic, ihe mejupụtara mkpụrụ ndụ ihe nketa, na ecology (autoecology/synecology) nke microorganisms.
Fig. 1. Isi mmalite na ụzọ nke PAH ndị dị ala na-agafe gburugburu ebe obibi dị iche iche na ihe dị iche iche na-emetụta biota. Ahịrị ndị a gbagọrọ agbagọ na-anọchite anya mmekọrịta dị n'etiti ihe ndị dị na gburugburu ebe obibi.
N'ime nyocha a, anyị agbalịala ịchịkọta data gbasara mmebi nke PAH dị mfe dịka naphthalene na naphthalenes ndị e tinyere n'ọnọdụ ha site na nje bacteria dị iche iche na-ekpuchi ụzọ metabolic na ụdị dị iche iche, enzymes ndị metụtara mmebi, nhazi mkpụrụ ndụ ihe nketa/ọdịnaya na ụdị dị iche iche, nzaghachi mkpụrụ ndụ na akụkụ dị iche iche nke bioremediation. Ịghọta ọkwa biochemical na molekul ga-enyere aka n'ịchọpụta ụdị ndị ọbịa kwesịrị ekwesị na injinịa mkpụrụ ndụ ihe nketa ha ọzọ maka mmezi bioremediation dị irè nke ihe ndị dị mkpa. Nke a ga-enyere aka n'ịmepụta atụmatụ maka ịmepụta consortia bacteria kpọmkwem maka bioremediation dị irè.
Ọnụnọ nke ọtụtụ ihe ndị na-esi ísì ụtọ na ihe ndị dị ize ndụ (na-eme ka iwu Huckel 4n + 2π elektrọn dị n'ime, n = 1, 2, 3, ...) na-eyi egwu dị ukwuu nye ọtụtụ ihe ndị dị gburugburu ebe obibi dịka ikuku, ala, ihe ndị dị n'ime ala, na elu na ala mmiri (Puglisi et al., 2007). Ihe ndị a nwere otu mgbanaka benzene (monocyclic) ma ọ bụ ọtụtụ mgbanaka benzene (polycyclic) nke edobere n'ụdị ahịrị, angular ma ọ bụ cluster ma na-egosipụta nkwụsi ike (nkwụsi ike/enweghị nkwụsi ike) na gburugburu ebe obibi n'ihi ike resonance dị elu na enweghị nrụgide (enweghị nrụgide), nke enwere ike ịkọwa site na oke ha na ọnọdụ ha dị ala. Mgbe ejiri methyl (-CH3), carboxyl (-COOH), hydroxyl (-OH), ma ọ bụ sulfonate (-HSO3) dochie mgbanaka aromatic ọzọ, ọ na-anọgidesi ike, nwee njikọ siri ike maka macromolecules, ma na-agbakọta bioaccumulative na sistemụ bayoloji (Seo et al., 2009; Phale et al., 2020). E tinyela ụfọdụ obere polycyclic aromatic hydrocarbons (LMWAHs) dị ala, dị ka naphthalene na ihe ndị sitere na ya [methylnaphthalene, naphthoic acid, naphthalenesulfonate, na 1-naphthyl N-methylcarbamate (carbaryl)], na ndepụta nke ihe ndị na-emerụ organic mbụ site na US Environmental Protection Agency dị ka genotoxic, mutagenic, na/ma ọ bụ carcinogenic (Cerniglia, 1984). Ịhapụ ụdị NM-PAH a n'ime gburugburu ebe obibi nwere ike ibute mkpokọta ihe ndị a na ọkwa niile nke usoro nri, si otú a na-emetụta ahụike nke gburugburu ebe obibi (Binkova et al., 2000; Srogi, 2007; Quinn et al., 2009).
Isi mmalite na ụzọ PAH si abanye na biota bụ site na mbugharị na mmekọrịta dị n'etiti ihe dị iche iche dị na gburugburu ebe obibi dịka ala, mmiri dị n'okpuru ala, mmiri elu, ihe ọkụkụ na ikuku (Arey na Atkinson, 2003). Foto nke 1 na-egosi mmekọrịta na nkesa nke PAH dị iche iche dị ala na gburugburu ebe obibi na ụzọ ha si abanye na biota/ikpughe mmadụ. A na-etinye PAH n'elu ala n'ihi mmetọ ikuku na site na mbugharị (mmiri) nke ikuku ụgbọala, gas ikuku ọkụ ụlọ ọrụ (gasification coal, combustion na coke) na ebe ha na-edebe. Ọrụ ụlọ ọrụ dịka imepụta ákwà sịntetik, agba na agba; nchekwa osisi; nhazi rọba; ọrụ mmepụta simenti; mmepụta ọgwụ ahụhụ; na ngwa ọrụ ugbo bụ isi iyi nke PAHs na sistemụ ala na mmiri (Bamforth na Singleton, 2005; Wick et al., 2011). Nnyocha egosila na ala dị n'ime ime obodo na n'obodo ukwu, n'akụkụ okporo ụzọ, na n'obodo ukwu, na-adịkarị mfe inweta polycyclic aromatic hydrocarbons (PAHs) n'ihi mwepụta sitere na ụlọ ọrụ ike, ikpo ọkụ ebe obibi, ibu okporo ụzọ ikuku na okporo ụzọ, na ọrụ owuwu (Suman et al., 2016). (2008) gosiri na PAHs dị n'ala dị nso n'okporo ụzọ na New Orleans, Louisiana, USA dị elu ruo 7189 μg/kg, ebe n'ime oghere mepere emepe, ha dị naanị 2404 μg/kg. N'otu aka ahụ, akọpụtala ọkwa PAH dị elu ruo 300 μg/kg n'ebe dị nso na ebe a na-emepụta coal na ọtụtụ obodo US (Kanaly na Harayama, 2000; Bamforth na Singleton, 2005). A kọọla na ala sitere n'obodo dị iche iche dị na India dịka Delhi (Sharma et al., 2008), Agra (Dubey et al., 2014), Mumbai (Kulkarni na Venkataraman, 2000) na Visakhapatnam (Kulkarni et al., 2014) nwere nnukwu PAHs. A na-etinye ihe ndị na-esi ísì ụtọ ngwa ngwa n'ime ájá, ihe ndị dị ndụ na ihe ndị dị n'ime ụrọ, si otú a na-aghọ nnukwu ebe a na-amịkọrọ carbon na gburugburu ebe obibi (Srogi, 2007; Peng et al., 2008). Isi iyi nke PAHs na gburugburu ebe obibi mmiri bụ mmiri ozuzo (mmiri ozuzo mmiri/mmiri kpọrọ nkụ na uzuoku mmiri), mmiri ozuzo obodo, mmiri mkpofu, mmiri mgbapụta mmiri mmiri wdg. (Srogi, 2007). A na-eme atụmatụ na ihe dị ka 80% nke PAHs na gburugburu ebe obibi mmiri sitere na mmiri ozuzo, mmiri ozuzo, na mwepụ ihe mkpofu (Motelay-Massei et al., 2006; Srogi, 2007). Oke PAH dị elu n'ime mmiri ma ọ bụ mmiri mmiri si n'ebe a na-ekpofu ihe siri ike na-abanye n'ime mmiri dị n'ime ala, nke na-eweta nnukwu ihe iyi egwu ahụike ọha na eze ebe ihe karịrị 70% nke ndị bi na South na Southeast Asia na-aṅụ mmiri dị n'ime ala (Duttagupta et al., 2019). Nnyocha Duttagupta et al. (2020) nke nyocha osimiri (32) na mmiri dị n'okpuru ala (235) sitere na West Bengal, India, chọpụtara na ihe dị ka 53% nke ndị bi n'obodo ukwu na 44% nke ndị bi n'ime ime obodo (ngụkọta nde mmadụ 20 bi) nwere ike ibute naphthalene (4.9–10.6 μg/L) na ihe ndị sitere na ya. A na-ewere usoro ojiji ala dị iche iche na mmụba nke mwepụta mmiri dị n'ime ala dị ka ihe ndị bụ isi na-achịkwa njem kwụ ọtọ (nkwado) nke PAHs dị obere n'ime ala. Achọpụtala na mmiri mmiri na-asọpụta n'ugbo, mmiri mkpofu obodo na ụlọ ọrụ mmepụta ihe, na mmiri mkpofu siri ike/mkpofu ahịhịa na-emetụta PAHs na mpaghara osimiri na sedimenti dị n'okpuru ala. Mmiri ozuzo na-eme ka mmetọ PAH ka njọ. A kọọla nnukwu PAH na ihe ndị sitere na alkyl ha (ngụkọta 51) n'osimiri/mmiri dị n'ụwa niile, dịka Osimiri Fraser, Osimiri Louan, Osimiri Denso, Osimiri Missouri, Osimiri Anacostia, Osimiri Ebro, na Osimiri Delaware (Yunker et al., 2002; Motelay-Massei et al., 2006; Li et al., 2010; Amoako et al., 2011; Kim et al., 2018). Na sedimenti dị n'akụkụ osimiri Ganges, achọpụtara na naphthalene na phenanthrene bụ ihe kachasị mkpa (achọpụtara na 70% nke ihe nlele) (Duttagupta et al., 2019). Ọzọkwa, ọmụmụ ihe egosila na chlorination nke mmiri ọṅụṅụ nwere ike ibute ịmepụta PAH ndị nwere oxygen na chlorinated karịa (Manoli na Samara, 1999). PAH na-agbakọta n'ime ọka, mkpụrụ osisi na akwụkwọ nri n'ihi na osisi na-eri site na ala ruru unyi, mmiri dị n'okpuru ala na mmiri ozuzo (Fismes et al., 2002). Ọtụtụ ihe ndị dị ndụ dị n'ime mmiri dịka azụ, mussels, clams na oporo na-emerụ PAH site na iri nri na mmiri mmiri ruru unyi, yana site na anụ ahụ na akpụkpọ ahụ (Mackay na Fraser, 2000). Ụzọ esi nri/nhazi dị ka ịsa ọkụ, ịcha ọkụ, ise anwụrụ, ighe, ịkpọ nkụ, ime achịcha na isi nri n'ọkụ nwekwara ike ibute nnukwu PAHs na nri. Nke a dabere na nhọrọ nke ihe na-ese anwụrụ, ọdịnaya phenolic/aromatic hydrocarbon, usoro esi nri, ụdị ihe na-ekpo ọkụ, ọdịnaya mmiri, ọkọnọ oxygen na okpomọkụ ọkụ (Guillén et al., 2000; Gomes et al., 2013). A chọpụtakwara polycyclic aromatic hydrocarbons (PAHs) na mmiri ara ehi na oke dị iche iche (0.75–2.1 mg/L) (Girelli et al., 2014). Nchịkọta nke PAH ndị a na nri daberekwa na njirimara physicochemical nke nri, ebe mmetụta ọjọọ ha metụtara ọrụ physiological, ọrụ metabolic, nnabata, nkesa na nkesa ahụ (Mechini et al., 2011).
A maara nsí na mmetụta ọjọọ nke polycyclic aromatic hydrocarbons (PAHs) kemgbe ogologo oge (Cherniglia, 1984). Obere molekul dị arọ nke polycyclic aromatic hydrocarbons (LMW-PAHs) (mgbanaka abụọ ruo atọ) nwere ike ijikọ na macromolecules dị iche iche dịka DNA, RNA na protein ma bụrụ ihe na-akpata kansa (Santarelli et al., 2008). N'ihi ọdịdị hydrophobic ha, a na-ekewa ha site na membranes lipid. N'ime mmadụ, cytochrome P450 monooxygenases na-eme ka PAHs dị na epoxides, ụfọdụ n'ime ha na-emeghachi omume nke ukwuu (dịka ọmụmaatụ, baediol epoxide) ma nwee ike ibute mgbanwe nke mkpụrụ ndụ nkịtị ka ọ bụrụ ndị na-emerụ ahụ (Marston et al., 2001). Na mgbakwunye, ngwaahịa mgbanwe nke PAHs dị ka quinones, phenols, epoxides, diols, wdg. na-egbu egbu karịa ihe ndị nne na nna mejupụtara. Ụfọdụ PAH na ihe ndị na-eme ka ahụ dị n'ime ha nwee ike imetụta homonụ na enzymes dị iche iche na metabolism, si otú a na-emetụta uto, sistemụ akwara etiti, sistemu ọmụmụ na sistemu ahụ ji alụso ọrịa ọgụ (Swetha na Phale, 2005; Vamsee-Krishna et al., 2006; Oostingh et al., 2008). Akọpụtala na obere oge ikpughe PAHs dị arọ molekul na-akpata nsogbu ọrụ akpa ume na thrombosis na ndị nwere asthma ma na-eme ka ihe ize ndụ nke kansa akpụkpọ ahụ, akpa ume, eriri afọ na eriri afọ dịkwuo elu (Olsson et al., 2010; Diggs et al., 2011). Ọmụmụ ihe anụmanụ egosikwala na ikpughe PAH nwere ike inwe mmetụta ọjọọ na ọrụ ọmụmụ na mmepe ma nwee ike ibute cataracts, mmebi akụrụ na imeju, na jaundice. Egosipụtala na ngwaahịa PAH biotransformation dị iche iche dịka diols, epoxides, quinones na free radicals (cations) na-emepụta ihe ndị DNA na-adọta. A chọpụtala na ndọtị ndị kwụsiri ike na-agbanwe igwe mmepụta DNA, ebe ndọtị ndị na-adịghị agbanwe agbanwe nwere ike iwepụ DNA (karịsịa na adenine na mgbe ụfọdụ na guanine); ha abụọ nwere ike ịkpata njehie ndị na-eduga na mgbanwe (Schweigert et al. 2001). Na mgbakwunye, quinones (benzo-/pan-) nwere ike ịmepụta ụdị oxygen reactive (ROS), na-akpata mmebi dị egwu na DNA na macromolecules ndị ọzọ, si otú a na-emetụta ọrụ/ịdị ndụ anụ ahụ (Ewa na Danuta 2017). Akọpụtala na mkpughe oge niile na obere mkpokọta pyrene, biphenyl na naphthalene na-akpata ọrịa kansa na anụmanụ nnwale (Diggs et al. 2012). N'ihi nsí ha na-egbu egbu, nhicha/iwepụ PAH ndị a na ebe emetụtara/merụrụ ahụ bụ ihe kacha mkpa.
E jirila ụzọ dị iche iche nke anụ ahụ na kemịkalụ wepụ PAHs n'ebe/gburugburu ndị ruru unyi. Usoro dịka ịgba ọkụ, iwepụ chlorination, oxidation UV, idozi, na mwepụ ihe mgbaze nwere ọtụtụ ọghọm, gụnyere ịmepụta ngwaahịa ndị na-egbu egbu, mgbagwoju anya usoro, nsogbu nchekwa na iwu, obere arụmọrụ, na ọnụ ahịa dị elu. Agbanyeghị, mbibi nje bacteria (a na-akpọ bioremediation) bụ ụzọ ọzọ dị mma nke gụnyere iji obere nje n'ụdị omenala ma ọ bụ colonies dị ọcha. Ma e jiri ya tụnyere ụzọ anụ ahụ na kemịkalụ, usoro a bụ nke na-adịghị emebi gburugburu ebe obibi, ọ naghị emerụ ahụ, ọ na-efu ego, ma na-adịgide adịgide. Enwere ike ime bioremediation na ebe emetụtara (in situ) ma ọ bụ na ebe a kwadebere nke ọma (ex situ) ya mere a na-ewere ya dị ka usoro mmezi na-adịgide adịgide karịa usoro anụ ahụ na kemịkalụ ọdịnala (Juhasz na Naidu, 2000; Andreoni na Gianfreda, 2007; Megharaj et al., 2011; Phale et al., 2020; Sarkar et al., 2020).
Ịghọta usoro metabolic nje ndị dị na mmebi nke ihe ndị na-eme ka ihe na-esi ísì ụtọ pụta nwere nnukwu mmetụta sayensị na akụ na ụba maka nkwado gburugburu ebe obibi na gburugburu ebe obibi. A na-echekwa ihe dị ka gram 2.1 × 1018 nke carbon (C) na sedimenti na ihe ndị sitere n'okike (ya bụ, mmanụ, gas eke, na kol, ya bụ, mmanụ ọkụ) n'ụwa niile, na-enye aka dị ukwuu na okirikiri carbon zuru ụwa ọnụ. Agbanyeghị, mmepe ngwa ngwa nke ụlọ ọrụ mmepụta ihe, mwepụta mmanụ ọkụ, na ọrụ mmadụ na-ebelata ebe nchekwa carbon lithospheric ndị a, na-ewepụta ihe dị ka 5.5 × 1015 g nke carbon organic (dị ka ihe na-emetọ) n'ime ikuku kwa afọ (Gonzalez-Gaya et al., 2019). Ọtụtụ n'ime carbon organic a na-abanye na gburugburu ebe obibi nke ala na mmiri site na sedimenti, njem, na mmiri. Na mgbakwunye, ihe ndị na-emetọ ihe ọhụrụ sitere na mmanụ ọkụ, dị ka plastik, ihe na-eme ka plastik kwụsie ike (phthalates na isomers ha), na-emerụ gburugburu ebe obibi mmiri, ala na mmiri na biota ha nke ukwuu, si otú a na-eme ka ihe egwu ihu igwe zuru ụwa ọnụ ka njọ. Ụdị microplastics dị iche iche, nanoplastics, iberibe plastik na ngwaahịa monomer ha na-egbu egbu sitere na polyethylene terephthalate (PET) agbakọtala na Oke Osimiri Pasifik n'etiti North America na Ndịda Ọwụwa Anyanwụ Eshia, na-emepụta "Nnukwu Pasifik Ahịhịa", na-emerụ ndụ mmiri (Newell et al., 2020). Ọmụmụ sayensị egosila na ọ gaghị ekwe omume iwepụ ihe ndị na-emerụ emerụ/ihe mkpofu dị otú ahụ site na ụzọ anụ ahụ ma ọ bụ kemịkalụ ọ bụla. N'ọnọdụ a, nje ndị kacha baa uru bụ ndị nwere ike ime ka ihe ndị na-emerụ emerụ ghara ịdị irè ka ha ghọọ carbon dioxide, ike kemịkalụ na ngwaahịa ndị ọzọ na-adịghị egbu egbu nke na-emesịa banye na usoro ịgba ígwè nri ndị ọzọ (H, O, N, S, P, Fe, wdg). Ya mere, ịghọta ecophysiology microbial nke mineralization nke ihe na-emetọ ihe na-esi ísì ụtọ na njikwa gburugburu ebe obibi ya dị oke mkpa maka ịtụle okirikiri carbon microbial, mmefu ego carbon na ihe egwu ihu igwe n'ọdịnihu. N'ihi mkpa dị ngwa iji wepụ ihe ndị dị otú ahụ na gburugburu ebe obibi, ọtụtụ ụlọ ọrụ gburugburu ebe obibi lekwasịrị anya na teknụzụ dị ọcha apụtala. N'aka nke ọzọ, a na-ewere ịtụle nke mkpofu/kemikal mkpofu ụlọ ọrụ mmepụta ihe ndị a na-agbakọ n'ime gburugburu ebe obibi (dịka ụzọ mkpofu gaa n'akụnụba) dị ka otu n'ime ogidi nke akụ na ụba gburugburu na ebumnuche mmepe na-adigide (Close et al., 2012). Ya mere, ịghọta akụkụ metabolic, enzymatic na mkpụrụ ndụ ihe nketa nke ndị a nwere ike imebi ihe dị oke mkpa maka iwepụ na imezi ihe ndị na-emerụ ahụ dị otú ahụ nke ọma.
N'ime ọtụtụ ihe ndị na-eme ka ihe dị nro dị ụtọ, anyị na-elebara anya nke ọma na PAH ndị dị obere dịka naphthalene na naphthalenes ndị a gbanwere. Ihe ndị a bụ isi ihe dị na mmanụ ọkụ sitere na mmanụ ala, agba ákwà, ngwaahịa ndị na-azụ ahịa, ọgwụ nje (mothballs na ọgwụ nje), ihe ndị na-eme ka ihe dị n'ime plastik na tannins, ya mere ha gbasaara n'ọtụtụ gburugburu ebe obibi (Preuss et al., 2003). Akụkọ ndị na-adịbeghị anya na-egosi mkpokọta naphthalene na sedimenti aquifer, ala mmiri na ala dị n'okpuru ala, mpaghara vadose na akwa osimiri, na-egosi bioaccumulation ya na gburugburu ebe obibi (Duttagupta et al., 2019, 2020). Tebụl nke abụọ na-achịkọta ihe ndị dị na physicochemical, ngwa na mmetụta ahụike nke naphthalene na ihe ndị sitere na ya. Ma e jiri ya tụnyere PAH ndị ọzọ dị elu, naphthalene na ihe ndị sitere na ya adịghị akpata hydrophobic, ha na-agbaze mmiri ma gbasaa nke ọma na gburugburu ebe obibi, yabụ a na-ejikarị ha eme ihe dị ka ihe nlereanya iji mụọ metabolism, mkpụrụ ndụ ihe nketa na ụdị metabolic nke PAHs. Ọtụtụ nje bacteria nwere ike ime ka naphthalene na ihe ndị sitere na ya gbazee, a na-enwetakwa ozi zuru oke gbasara ụzọ metabolic ha, enzymes na atụmatụ nchịkwa (Mallick et al., 2011; Phale et al., 2019, 2020). Na mgbakwunye, a na-akpọ naphthalene na ihe ndị sitere na ya ihe atụ maka nyocha mmetọ gburugburu ebe obibi n'ihi oke ha na nnweta bioavailability ha. US Environmental Protection Agency na-eme atụmatụ na nkezi ọkwa naphthalene dị 5.19 μg kwa cubic mita site na anwụrụ sịga, ọkachasị site na ọkụ na-ezughị ezu, na 7.8 ruo 46 μg site na anwụrụ ọkụ n'akụkụ, ebe ikpughe na creosote na naphthalene dị okpukpu 100 ruo 10,000 karịa (Preuss et al. 2003). A chọpụtala naphthalene karịsịa na ọ nwere nsị iku ume na kansa nke ụdị, mpaghara, na mmekọahụ. Dabere na ọmụmụ anụmanụ, International Agency for Research on Cancer (IARC) ekewaala naphthalene dị ka "nwere ike ibute kansa mmadụ" (Group 2B)1. Ikpughe na naphthalenes ndị a na-eji dochie anya, nke kachasị site na iku ume ma ọ bụ inye parenteral (ọnụ), na-akpata mmerụ ahụ n'anụ ahụ akpa ume ma na-eme ka ọnụọgụ nke etuto akpa ume dịkwuo elu n'ime oke na òké (Ngalaba Toxicology Program 2). Mmetụta dị oke njọ gụnyere ọgbụgbọ, ọgbụgbọ, mgbu afọ, afọ ọsịsa, isi ọwụwa, mgbagwoju anya, ọsụsọ dị ukwuu, ahụ ọkụ, tachycardia, wdg. N'aka nke ọzọ, a kọwo na carbaryl ọgwụ ahụhụ nke nwere ọtụtụ ụdị carbamate (1-naphthyl N-methylcarbamate) na-egbu egbu nye ndị na-enweghị mmiri, amphibians, aṅụ mmanụ aṅụ na ụmụ mmadụ ma egosila na ọ na-egbochi acetylcholinesterase na-akpata nkwarụ (Smulders et al., 2003; Bulen na Distel, 2011). Ya mere, ịghọta usoro nke mmebi nje, nhazi mkpụrụ ndụ ihe nketa, mmeghachi omume enzymatic na sel dị oke mkpa maka ịmepụta atụmatụ bioremediation na gburugburu ebe ruru unyi.
Tebụl 2. Ozi zuru ezu gbasara njirimara nke physicochemical, ojiji, ụzọ njirimara na ọrịa ndị metụtara naphthalene na ihe ndị sitere na ya.
N'ime ebe ndị e merụrụ emerụ, ihe ndị na-eme ka ihe na-esi ísì ụtọ dị ka hydrophobic na lipophilic nwere ike ịkpata ọtụtụ mmetụta sel na microbiome gburugburu ebe obibi (obodo), dịka mgbanwe na mmiri mmiri akpụkpọ ahụ, ikike ime ka akpụkpọ ahụ dị ọcha, ọzịza lipid bilayer, mmebi nke nnyefe ike (ike njem eletrọn/ike proton), na ọrụ nke protein ndị metụtara membrane (Sikkema et al., 1995). Na mgbakwunye, ụfọdụ ihe ndị na-agbaze agbaze dị ka catechols na quinones na-emepụta ụdị oxygen reactive (ROS) ma na-etolite ihe ndị nwere DNA na protein (Penning et al., 1999). Ya mere, ọtụtụ ihe ndị dị otú ahụ na gburugburu ebe obibi na-etinye nrụgide nhọrọ na obodo microbial iji bụrụ ndị na-emebi ihe nke ọma na ọkwa dị iche iche nke physiological, gụnyere nnabata/njem, mgbanwe intracellular, njikọta/iji ya, na nhazi.
Nchọcha nke Ribosomal Database Project-II (RDP-II) gosiri na mkpokọta ụdị nje bacteria 926 ka ewepụtara site na ọdịbendị mgbasa ozi ma ọ bụ mmụba nke naphthalene ma ọ bụ ihe ndị sitere na ya. Otu Proteobacteria nwere ọnụọgụgụ kachasị elu nke ndị nnọchi anya (n = 755), nke sochiri Firmicutes (52), Bacteroidetes (43), Actinobacteria (39), Tenericutes (10), na nje bacteria a na-ekewaghị ekewa (8) (Foto nke 2). Ndị nnọchi anya γ-Proteobacteria (Pseudomonadales na Xanthomonadales) chịrị otu Gram-negative niile nwere nnukwu G+C (54%), ebe Clostridiales na Bacillales (30%) bụ otu Gram-positive nwere obere G+C. A kọrọ na Pseudomonas (ọnụọgụgụ kachasị elu, ụdị 338) nwere ike imebi naphthalene na ihe ndị sitere na methyl ya n'ọtụtụ gburugburu ebe obibi rụrụ arụ (kọl tar, mmanụ ala, mmanụ ala, sludge, mmanụ a wụfuru, mmiri mkpofu, ihe mkpofu organic na ebe a na-ekpofu ihe) yana na gburugburu ebe obibi na-adịghị emebi emebi (ala, osimiri, sedimenti na mmiri ala) (Foto nke 2). Ọzọkwa, ọmụmụ ihe bara ụba na nyocha metagenomic nke ụfọdụ n'ime mpaghara ndị a kpughere na ụdị Legionella na Clostridium na-enweghị ubi nwere ike inwe ikike imebi, na-egosi mkpa ọ dị ịkọpụta nje bacteria ndị a iji mụọ ụzọ ọhụrụ na ụdị dị iche iche nke metabolic.
Foto nke 2. Ụdị dị iche iche nke taxonomic na nkesa gburugburu ebe obibi nke ndị nnọchite anya nje bacteria na gburugburu ebe obibi nke e merụrụ site na ihe ndị sitere na naphthalene na naphthalene.
N'ime ọtụtụ nje dị iche iche na-emebi ihe na-esi ísì ụtọ nke na-emebi hydrocarbon, ọtụtụ n'ime ha nwere ike imebi naphthalene dị ka naanị isi iyi nke carbon na ike. A kọwawo usoro ihe omume ndị metụtara metabolism naphthalene maka Pseudomonas sp. (ụdị: NCIB 9816-4, G7, AK-5, PMD-1 na CSV86), Pseudomonas stutzeri AN10, Pseudomonas fluorescens PC20 na ụdị ndị ọzọ (ND6 na AS1) (Mahajan et al., 1994; Resnick et al., 1996; Annweiler et al., 2000; Basu et al., 2003; Dennis na Zylstra, 2004; Sota et al., 2006; A na-amalite metabolism site na dioxygenase multicomponent [naphthalene dioxygenase (NDO), mgbanaka hydroxylating dioxygenase] nke na-akwalite oxidation nke otu n'ime mgbanaka aromatic nke naphthalene site na iji oxygen molekul dị ka ihe ọzọ dị n'okpuru, na-agbanwe naphthalene ka ọ bụrụ cis-naphthalenediol (Foto 3). A na-agbanwe Cis-dihydrodiol ka ọ bụrụ 1,2-dihydroxynaphthalene site na dehydrogenase. Dioxygenase nke na-agbaji mgbanaka, 1,2-dihydroxynaphthalene dioxygenase (12DHNDO), na-agbanwe 1,2-dihydroxynaphthalene ka ọ bụrụ 2-hydroxychromene-2-carboxylic acid. Isomerization nke enzymatic cis-trans na-emepụta trans-o-hydroxybenzylidenepyruvate, nke hydratase aldolase kewara ka ọ bụrụ salicylic aldehyde na pyruvate. Organic acid pyruvate bụ ihe mbụ C3 sitere na ọkpụkpụ carbon naphthalene ma duzie ya n'ime ụzọ carbon etiti. Na mgbakwunye, salicylaldehyde dehydrogenase nke NAD+ na-adabere na ya na-agbanwe salicylaldehyde ka ọ bụrụ salicylic acid. A na-akpọ metabolism n'oge a "ụzọ elu" nke mmebi naphthalene. Ụzọ a na-adịkarị na ọtụtụ nje bacteria naphthalene na-emebi emebi. Agbanyeghị, enwere ihe ole na ole dị iche; dịka ọmụmaatụ, na thermophilic Bacillus hamburgii 2, Naphthalene 2,3-dioxygenase na-amalite mmebi naphthalene iji mepụta 2,3-dihydroxynaphthalene (Anweiler et al., 2000).
Foto nke 3. Ụzọ nke naphthalene, methylnaphthalene, naphthoic acid, na carbaryl deterioration. Ọnụọgụ ndị gbara okirikiri na-anọchite anya enzymes ndị na-akpata mgbanwe usoro nke naphthalene na ihe ndị sitere na ya ka ha bụrụ ngwaahịa ndị na-esote. 1 — naphthalene dioxygenase (NDO); 2, cis-dihydrodiol dehydrogenase; 3, 1,2-dihydroxynaphthalene dioxygenase; 4, 2-hydroxychromene-2-carboxylic acid isomerase; 5, trans-O-hydroxybenzylidenepyruvate hydratase aldolase; 6, salicylaldehyde dehydrogenase; 7, salicylate 1-hydroxylase; 8, catechol 2,3-dioxygenase (C23DO); 9, 2-hydroxymuconate semialdehyde dehydrogenase; 10, 2-oxopent-4-enoate hydratase; 11, 4-hydroxy-2-oxopentanoate aldolase; 12, acetaldehyde dehydrogenase; 13, catechol-1,2-dioxygenase (C12DO); 14, muconate cycloisomerase; 15, muconolactone delta-isomerase; 16, β-ketoadipatenollactone hydrolase; 17, β-ketoadipate succinyl-CoA transferase; 18, β-ketoadipate-CoA thiolase; 19, succinyl-CoA: acetyl-CoA succinyltransferase; 20, salicylate 5-hydroxylase; 21 - gentisate 1,2-dioxygenase (GDO); 22, maleylpyruvate isomerase; 23, fumarylpyruvate hydrolase; 24, methylnaphthalene hydroxylase (NDO); 25, hydroxymethylnaphthalene dehydrogenase; 26, naphthaldehyde dehydrogenase; 27, 3-formylsalicylic acid oxidase; 28, hydroxyisophthalate decarboxylase; 29, carbaryl hydrolase (CH); 30, 1-naphthol-2-hydroxylase.
Dabere na ihe dị ndụ na mkpụrụ ndụ ihe nketa ya, a na-eme ka salicylic acid si na ya pụta dịkwuo mma site na ụzọ catechol site na iji salicylate 1-hydroxylase (S1H) ma ọ bụ site na ụzọ gentisate site na iji salicylate 5-hydroxylase (S5H) (Foto nke 3). Ebe ọ bụ na salicylic acid bụ isi etiti na metabolism naphthalene (ụzọ elu), a na-akpọkarị usoro site na salicylic acid gaa na etiti TCA dị ka ụzọ dị ala, a na-ahazikwa mkpụrụ ndụ ihe nketa n'ime otu operon. Ọ bụ ihe a na-ahụkarị ịhụ na mkpụrụ ndụ ihe nketa dị na ụzọ elu operon (nah) na ụzọ ala operon (sal) na-achịkwa site na ihe ndị na-achịkwa nkịtị; dịka ọmụmaatụ, NahR na salicylic acid na-arụ ọrụ dị ka ihe na-akpali akpali, na-enye ohere ka operon abụọ ahụ metabolize naphthalene kpamkpam (Phale et al., 2019, 2020).
Tinyere nke a, a na-ekewa catechol n'ụzọ cyclic na 2-hydroxymuconate semialdehyde site na ụzọ meta site na catechol 2,3-dioxygenase (C23DO) (Yen et al., 1988) ma jiri 2-hydroxymuconate semialdehyde hydrolase mee ka ọ bụrụ 2-hydroxypent-2,4-dienoic acid. A na-agbanwe 2-hydroxypent-2,4-dienoate ka ọ bụrụ pyruvate na acetaldehyde site na hydratase (2-oxopent-4-enoate hydratase) na aldolase (4-hydroxy-2-oxopentanoate aldolase) wee banye n'okporo ụzọ carbon etiti (Foto 3). N'aka nke ọzọ, a na-ekewa catechol n'ụzọ cyclic na cis,cis-muconate site na ụzọ ortho site na catechol 1,2-oxygenase (C12DO). Muconate cycloisomerase, muconolactone isomerase, na β-ketoadipate-nollactone hydrolase na-agbanwe cis,cis-muconate ka ọ bụrụ 3-oxoadipate, nke na-abanye n'okporo ụzọ carbon etiti site na succinyl-CoA na acetyl-CoA (Nozaki et al., 1968) (Foto 3).
N'ụzọ gentisate (2,5-dihydroxybenzoate), a na-ekewa mgbanaka aromatic site na gentisate 1,2-dioxygenase (GDO) iji mepụta maleylpyruvate. Enwere ike itinye ngwaahịa a ozugbo na pyruvate na malate, ma ọ bụ enwere ike itinye ya na isomerylpyruvate, nke enwere ike itinye ya na pyruvate na fumarate (Larkin na Day, 1986). A hụla nhọrọ nke ụzọ ọzọ na nje bacteria Gram-negative na Gram-positive na ọkwa biochemical na mkpụrụ ndụ ihe nketa (Morawski et al., 1997; Whyte et al., 1997). Bakteria Gram-negative (Pseudomonas) na-ahọrọ iji salicylic acid, nke bụ ihe na-akpali metabolism naphthalene, na-ewepụ ya na catechol site na iji salicylate 1-hydroxylase (Gibson na Subramanian, 1984). N'aka nke ọzọ, na nje bacteria Gram-positive (Rhodococcus), salicylate 5-hydroxylase na-agbanwe salicylic acid ka ọ bụrụ gentisic acid, ebe salicylic acid enweghị mmetụta inductive na nsụgharị nke mkpụrụ ndụ ihe nketa naphthalene (Grund et al., 1992) (Foto 3).
Akọpụtala na ụdị dị iche iche dịka Pseudomonas CSV86, Oceanobacterium NCE312, Marinhomonas naphthotrophicus, Sphingomonas paucimobilis 2322, Vibrio cyclotrophus, Pseudomonas fluorescens LP6a, Pseudomonas na ụdị Mycobacterium nwere ike imebi monomethylnaphthalene ma ọ bụ dimethylnaphthalene (Dean-Raymond na Bartha, 1975; Cane na Williams, 1982; Mahajan et al., 1994; Dutta et al., 1998; Hedlund et al., 1999). N'ime ha, a mụọla ụzọ mbibi 1-methylnaphthalene na 2-methylnaphthalene nke Pseudomonas sp. CSV86 nke ọma na ọkwa biochemical na enzymatic (Mahajan et al., 1994). 1-Methylnaphthalene na-agbanwe site na ụzọ abụọ. Nke mbụ, a na-eme ka mgbanaka aromatic dị nro (mgbanaka methylnaphthalene a na-agbanweghị agbanwe) mepụta cis-1,2-dihydroxy-1,2-dihydro-8-methylnaphthalene, nke a na-eme ka ọ bụrụ methyl salicylate na methylcatechol, wee banye n'okporo ụzọ carbon etiti mgbe e kewasịrị mgbanaka ahụ (Foto 3). A na-akpọ ụzọ a "ụzọ isi iyi carbon". Na "ụzọ mwepụta ihe mkpofu" nke abụọ, enwere ike iji NDO mee ka otu methyl dị na ya dị ka 1-hydroxymethylnaphthalene, nke a na-eme ka ọ dị ka 1-naphthoic acid ma wepụ ya n'ime usoro ọdịbendị dị ka ngwaahịa na-adịghị mma. Ọmụmụ ihe egosila na ụdị CSV86 enweghị ike itolite na 1- na 2-naphthoic acid dị ka naanị isi iyi carbon na ike, na-akwado ụzọ mwepụta ihe mkpofu ya (Mahajan et al., 1994; Basu et al., 2003). Na 2-methylnaphthalene, otu methyl ahụ na-enweta hydroxylation site na hydroxylase iji mepụta 2-hydroxymethylnaphthalene. Na mgbakwunye, mgbanaka na-enweghị nnọchi nke mgbanaka naphthalene na-agafe hydroxylation mgbanaka iji mepụta dihydrodiol, nke a na-eme ka ọ bụrụ 4-hydroxymethylcatechol na usoro mmeghachi omume enzyme-catalyzed ma banye n'okporo ụzọ carbon etiti site na ụzọ cleavage meta-ring. N'otu aka ahụ, a kọrọ na S. paucimobilis 2322 jiri NDO mee hydroxylate 2-methylnaphthalene, nke a na-eme ka ọ dịkwuo oxidized iji mepụta methyl salicylate na methylcatechol (Dutta et al., 1998).
Naphthoic acids (ndị a gbanwere/ndị a na-agbanweghi agbanwe) bụ ngwaahịa ndị e mepụtara n'oge mmebi nke methylnaphthalene, phenanthrene na anthracene ma wepụta ha n'ime ihe e ji eme ihe. Akọpụtala na ala na-ekewapụ Stenotrophomonas maltophilia CSV89 nwere ike ime ka 1-naphthoic acid dị ka isi iyi carbon (Phale et al., 1995). Metabolism na-amalite site na dihydroxylation nke mgbanaka aromatic iji mepụta 1,2-dihydroxy-8-carboxynaphthalene. A na-eme ka diol nke sitere na ya dị ka catechol site na 2-hydroxy-3-carboxybenzylidenepyruvate, 3-formylsalicylic acid, 2-hydroxyisophthalic acid na salicylic acid wee banye n'okporo ụzọ carbon etiti site na ụzọ meta-ring cleavage (Foto 3).
Carbaryl bụ ọgwụ naphthyl carbamate. Kemgbe mgbanwe Green na India n'afọ 1970, iji fatịlaịza kemịkalụ na ọgwụ ahụhụ emeela ka mmụba nke mwepụta polycyclic aromatic hydrocarbon (PAH) sitere na isi mmalite ọrụ ugbo na-abụghị isi (Pingali, 2012; Duttagupta et al., 2020). A na-eji ọgwụ nje kemịkalụ agwọ ihe ruru 55% (hekta 85,722,000) nke ala ubi niile dị na India. N'ime afọ ise gara aga (2015–2020), ngalaba ọrụ ugbo India ejirila nkezi nke tọn 55,000 ruo 60,000 nke ọgwụ nje kwa afọ (Ngalaba Ndị Ọrụ Ugbo na Ọdịmma Ndị Ọrụ Ugbo, Ministry of Agriculture, Government of India, August 2020). Na ugwu na etiti Gangetic plains (steeti nwere ọnụ ọgụgụ mmadụ kachasị elu na ọnụọgụgụ mmadụ), ojiji nke ọgwụ nje na ihe ọkụkụ zuru ebe niile, ebe ọgwụ nje na-abụkarị ihe a na-ahụkarị. Carbaryl (1-naphthyl-N-methylcarbamate) bụ ọgwụ ahụhụ nke nwere ọtụtụ ihe dị iche iche, nke na-egbu egbu ma na-egbu egbu nke a na-eji arụ ọrụ ugbo India na nkezi ọnụego nke tọn 100-110. A na-ere ya n'aha azụmaahịa Sevin ma a na-eji ya achịkwa ụmụ ahụhụ (aphids, ndanda ọkụ, fleas, mites, spiders na ọtụtụ nje ndị ọzọ dị n'èzí) na-emetụta ọtụtụ ihe ọkụkụ (ọka, soybean, owu, mkpụrụ osisi na akwụkwọ nri). Enwere ike iji ụfọdụ nje dị ndụ dịka Pseudomonas (NCIB 12042, 12043, C4, C5, C6, C7, Pseudomonas putida XWY-1), Rhodococcus (NCIB 12038), Sphingobacterium spp. (CF06), Burkholderia (C3), Micrococcus na Arthrobacter chịkwaa ahụhụ ndị ọzọ. Akọpụtala na RC100 nwere ike imebi carbaryl (Larkin na Day, 1986; Chapalamadugu na Chaudhry, 1991; Hayatsu et al., 1999; Swetha na Phale, 2005; Trivedi et al., 2017). A mụọla ụzọ mbibi nke carbaryl nke ọma na ọkwa biochemical, enzymatic na mkpụrụ ndụ ihe nketa na ihe ndị dị na ala nke Pseudomonas sp. Ụdị C4, C5 na C6 (Swetha na Phale, 2005; Trivedi et al., 2016) (Foto 3). Ụzọ metabolic na-amalite site na hydrolysis nke njikọ ester site na carbaryl hydrolase (CH) iji mepụta 1-naphthol, methylamine na carbon dioxide. A na-agbanwe 1-naphthol ka ọ bụrụ 1,2-dihydroxynaphthalene site na 1-naphthol hydroxylase (1-NH), nke a na-agbanwe site na ụzọ carbon etiti site na salicylate na gentisate. Akọpụtala na ụfọdụ nje bacteria na-emebi carbaryl na-agbanwe ya ka ọ bụrụ salicylic acid site na nkewa nke mgbanaka catechol ortho (Larkin na Day, 1986; Chapalamadugu na Chaudhry, 1991). Ihe pụrụ iche bụ na nje bacteria na-emebi naphthalene na-agbanwekarị salicylic acid site na catechol, ebe nje bacteria na-emebi carbaryl na-ahọrọ ịgbanwe salicylic acid site na ụzọ gentisate.
Enwere ike iji ihe ndị sitere na Naphthalenesulfonic acid/disulfonic acid na naphthylaminesulfonic acid dị ka ihe ndị na-eme ka ihe dị n'etiti ihe na-emepụta agba azo, ihe ndị na-eme ka mmiri dị mmiri mmiri, ihe ndị na-agbasa ihe, wdg. Ọ bụ ezie na ihe ndị a nwere obere nsí nye ụmụ mmadụ, nyocha cytotoxicity egosila na ha na-egbu azụ, daphnia na algae (Greim et al., 1994). Akọpụtala na ndị nnọchi anya ụdị Pseudomonas (ụdị A3, C22) na-amalite metabolism site na okpukpu abụọ nke hydroxylation nke mgbanaka aromatic nwere otu sulfonic acid iji mepụta dihydrodiol, nke a na-agbanwekwu ka ọ bụrụ 1,2-dihydroxynaphthalene site na nkewa nke otu sulfite (Brilon et al., 1981). A na-eme ka 1,2-dihydroxynaphthalene nke sitere na ya pụta site na ụzọ naphthalene ochie, ya bụ, ụzọ catechol ma ọ bụ gentisate (Foto 4). A gosila na aminonaphthalenesulfonic acid na hydroxynaphthalenesulfonic acid nwere ike imebi kpamkpam site na ngwakọta nje bacteria na ụzọ catabolic (Nortemann et al., 1986). Egosila na otu onye n'ime ndị otu ahụ na-ewepụ aminonaphthalenesulfonic acid ma ọ bụ hydroxynaphthalenesulfonic acid site na 1,2-dioxygenation, ebe a na-ahapụ aminosalicylate ma ọ bụ hydroxysalicylate n'ime usoro ọdịbendị dị ka metabolite dead-end ma mesịa ndị otu ndị ọzọ nke ndị otu ahụ na-ewere ya. Naphthalenedisulfonic acid dịtụ polar mana ọ naghị emebi emebi nke ọma, ya mere enwere ike ịgbanwe ya site na ụzọ dị iche iche. Desulfurization mbụ na-eme n'oge regioselective dihydroxylation nke aromatic ring na otu sulfonic acid; Mwepụ nke abụọ nke mmiri mmiri mmiri na-eme n'oge hydroxylation nke 5-sulfosalicylic acid site na salicylic acid 5-hydroxylase iji mepụta gentisic acid, nke na-abanye n'okporo ụzọ carbon dị n'etiti (Brilon et al., 1981) (Foto 4). Enzymes ndị na-akpata mbibi naphthalene bụkwa ndị na-akpata metabolism naphthalene sulfonate (Brilon et al., 1981; Keck et al., 2006).
Foto nke 4. Ụzọ metabolic maka mmebi naphthalene sulfonate. Ọnụọgụ dị n'ime okirikiri na-anọchite anya enzymes ndị na-akpata metabolism naphthyl sulfonate, nke yiri/yiri enzymes akọwara na FIG. 3.
PAHs dị obere (LMW-PAHs) bụ ndị a na-ebelata, ndị na-enwe mmetụta hydrophobic na ndị na-anaghị agbaze nke ọma, ya mere ha anaghị enwe ike imebi/emebi ihe eke. Agbanyeghị, obere ihe ndị dị ndụ aerobic nwere ike ime ka ọ dị oxidize site na ịmịkọrọ oxygen molekul (O2). Enzymes ndị a bụ nke otu n'ime klaasị oxidoreductases ma nwee ike ime mmeghachi omume dị iche iche dịka aromatic ring hydroxylation (mono- ma ọ bụ dihydroxylation), dehydrogenation na aromatic ring cleavage. Ngwaahịa ndị a na-enweta site na mmeghachi omume ndị a dị n'ọnọdụ oxidation dị elu ma a na-agbanwe ha ngwa ngwa site na ụzọ carbon etiti (Phale et al., 2020). Akọpụtala na enzymes dị na ụzọ mbibi nwere ike ime ka ha rụọ ọrụ. Ọrụ nke enzymes ndị a dị obere ma ọ bụ enweghị atụ mgbe a na-etolite mkpụrụ ndụ na isi iyi carbon dị mfe dị ka glucose ma ọ bụ organic acids. Tebụl 3 na-achịkọta enzymes dị iche iche (oxygenases, hydrolases, dehydrogenases, oxidases, wdg) ndị metụtara metabolism nke naphthalene na ihe ndị sitere na ya.
Tebụl 3. Àgwà biochemical nke enzymes ndị na-akpata mmebi nke naphthalene na ihe ndị sitere na ya.
Ọmụmụ ihe gbasara redioisotope (18O2) egosila na itinye O2 molekul n'ime mgbanaka aromatic site na oxygenases bụ nzọụkwụ kachasị mkpa n'ịkwalite mmebi ọzọ nke ihe mejupụtara (Hayaishi et al., 1955; Mason et al., 1955). Ntinye nke otu atọm oxygen (O) site na oxygen molekul (O2) n'ime ihe mejupụtara ya bụ site na ma monooxygenases endogenous ma ọ bụ exogenous (a na-akpọkwa hydroxylases). A na-ebelata atọm oxygen ọzọ ka ọ bụrụ mmiri. Monooxygenases exogenous na-ebelata flavin na NADH ma ọ bụ NADPH, ebe na endomonooxygenases flavin na-ebelata site na ihe mejupụtara ya. Ọnọdụ hydroxylation na-ebute ụdị dị iche iche na nhazi ngwaahịa. Dịka ọmụmaatụ, salicylate 1-hydroxylase hydroxylates salicylic acid na ọnọdụ C1, na-emepụta catechol. N'aka nke ọzọ, salicylate 5-hydroxylase nke nwere ọtụtụ ihe mejupụtara (nke nwere reductase, ferredoxin, na oxygenase subunits) hydroxylates salicylic acid n'ọnọdụ C5, na-emepụta gentisic acid (Yamamoto et al., 1965).
Dioxygenases na-etinye atọm O2 abụọ n'ime ihe ndị dị n'okpuru ala. Dabere na ngwaahịa ndị e mepụtara, a na-ekewa ha n'ime dioxygenases hydroxylating ring na dioxygenases ndị na-agbaji mgbanaka. Dioxygenases ring hydroxylating na-agbanwe ihe ndị dị n'ime aromatic ka ọ bụrụ cis-dihydrodiols (dịka ọmụmaatụ, naphthalene) ma gbasaa n'etiti nje bacteria. Ruo taa, egosila na ihe ndị dị ndụ nwere ring hydroxylating dioxygenases nwere ike itolite na isi iyi carbon dị iche iche, a na-ekewakwa enzymes ndị a dị ka NDO (naphthalene), toluene dioxygenase (TDO, toluene), na biphenyl dioxygenase (BPDO, biphenyl). Ma NDO na BDO nwere ike ime ka hydroxylation okpukpu abụọ na nke dị n'akụkụ nke ọtụtụ polycyclic aromatic hydrocarbons dị iche iche (toluene, nitrotoluene, xylene, ethylbenzene, naphthalene, biphenyl, fluorene, indole, methylnaphthalene, naphthalenesulfonate, phenanthrene, anthracene, acetophenone, wdg) (Boyd na Sheldrake, 1998; Phale et al., 2020). NDO bụ sistemụ ọtụtụ ihe mejupụtara oxidoreductase, ferredoxin, na ihe mejupụtara oxygenase nke nwere ebe na-arụ ọrụ (Gibson na Subramanian, 1984; Resnick et al., 1996). Ngalaba catalytic nke NDO nwere nnukwu α subunit na obere β subunit nke edobere na nhazi α3β3. NDO bụ nke nnukwu ezinụlọ oxygenases, α-subunit ya nwekwara ebe Rieske [2Fe-2S] na mononuclear iron na-abụghị heme, nke na-ekpebi kpọmkwem ihe mejupụtara NDO (Parales et al., 1998). Dịka ọ na-adịkarị, n'otu okirikiri catalytic, a na-ebufe elektrọn abụọ site na mbelata nke pyridine nucleotide na ion Fe(II) na saịtị na-arụ ọrụ site na reductase, ferredoxin na saịtị Rieske. Ihe nhata ndị ahụ na-ebelata na-eme ka oxygen molecular rụọ ọrụ, nke bụ ihe dị mkpa maka substrate dihydroxylation (Ferraro et al., 2005). Ruo taa, naanị ole na ole NDO ka e sachara ma kọwaa n'ụzọ zuru ezu site na ụdị dị iche iche, a mụkwara njikwa mkpụrụ ndụ ihe nketa nke ụzọ ndị metụtara mmebi naphthalene n'ụzọ zuru ezu (Resnick et al., 1996; Parales et al., 1998; Karlsson et al., 2003). Ndị na-eme ka ihe dị n'ime ha dị iche iche (enzymes endo- ma ọ bụ ortho-ring-cleaving na enzymes exodiol- ma ọ bụ meta-ring-cleaving) na-arụ ọrụ na ihe ndị na-eme ka ihe dị n'ime ha dị ka hydroxylated aromatic compounds. Dịka ọmụmaatụ, dioxygenase ortho-ring-cleaving bụ catechol-1,2-dioxygenase, ebe dioxygenase meta-ring-cleaving bụ catechol-2,3-dioxygenase (Kojima et al., 1961; Nozaki et al., 1968). Na mgbakwunye na oxygenase dị iche iche, enwerekwa ọtụtụ dehydrogenases na-akpata mwepụ nke aromatic dihydrodiols, alcohols na aldehydes na iji NAD+/NADP+ dị ka ndị na-anabata elektrọn, nke bụ ụfọdụ n'ime enzymes dị mkpa metụtara metabolism (Gibson na Subramanian, 1984; Shaw na Harayama, 1990; Fahle et al., 2020).
Enzymes dị ka hydrolases (esterases, amidases) bụ klas nke abụọ dị mkpa nke enzymes ndị na-eji mmiri ekewapụ njikọ covalent ma gosipụta nkọwapụta substrate sara mbara. A na-ewere Carbaryl hydrolase na hydrolases ndị ọzọ dị ka akụkụ nke periplasm (transmembrane) na ndị otu nje bacteria Gram-negative (Kamini et al., 2018). Carbaryl nwere njikọ amide na ester; ya mere, enwere ike ịme ka ọ dị mmiri site na esterase ma ọ bụ amidase iji mepụta 1-naphthol. Akọpụtala na Carbaryl dị na Rhizobium rhizobium strain AC10023 na Arthrobacter strain RC100 na-arụ ọrụ dị ka esterase na amidase, n'otu n'otu. Carbaryl dị na Arthrobacter strain RC100 na-arụkwa ọrụ dị ka amidase. Egosila na RC100 na-eme ka ọgwụ ahụhụ anọ nke N-methylcarbamate dị ka carbaryl, methomyl, mefenamic acid na XMC dị mmiri mmiri (Hayaatsu et al., 2001). A kọrọ na CH dị na Pseudomonas sp. C5pp nwere ike ime ihe na carbaryl (ọrụ 100%) na 1-naphthyl acetate (ọrụ 36%), mana ọ bụghị na 1-naphthylacetamide, nke na-egosi na ọ bụ esterase (Trivedi et al., 2016).
Ọmụmụ ihe gbasara biochemical, ụkpụrụ nhazi enzyme, na nyocha mkpụrụ ndụ ihe nketa egosila na mkpụrụ ndụ ihe nketa naphthalene nwere nkeji nhazi abụọ ma ọ bụ "operon": nah ("ụzọ elu", ịtụgharị naphthalene ka ọ bụrụ salicylic acid) na sal ("ụzọ ala", na-agbanwe salicylic acid ka ọ bụrụ ụzọ carbon etiti site na catechol). Salicylic acid na ihe ndị yiri ya nwere ike ịrụ ọrụ dị ka ihe mkpali (Shamsuzzaman na Barnsley, 1974). N'ịnọ n'ihu glucose ma ọ bụ organic acids, a na-egbochi operon. Foto nke 5 na-egosi nhazi mkpụrụ ndụ ihe nketa zuru oke nke mmebi naphthalene (n'ụdị operon). A kọwawo ọtụtụ ụdị/ụdị aha nke mkpụrụ ndụ ihe nketa nah (ndo/pah/dox) ma chọpụta na ha nwere njikọ dị elu (90%) n'etiti ụdị Pseudomonas niile (Abbasian et al., 2016). A na-ahazi mkpụrụ ndụ ihe nketa nke ụzọ elu naphthalene n'usoro nkwekọrịta dịka egosiri na Foto 5A. A kọkwara na mkpụrụ ndụ ihe nketa ọzọ, nahQ, na-etinye aka na metabolism naphthalene ma na-adịkarị n'etiti nahC na nahE, mana ọrụ ya n'ezie ka a ka ga-akọwa. N'otu aka ahụ, a hụrụ mkpụrụ ndụ ihe nketa nahY, nke na-akpata chemotaxis naphthalene na-emetụta, na njedebe nke nah operon na ụfọdụ ndị so na ya. Na Ralstonia sp., a chọpụtara na mkpụrụ ndụ ihe nketa U2 nke na-akọwa glutathione S-transferase (gsh) dị n'etiti nahAa na nahAb mana ọ metụtaghị njirimara ojiji naphthalene (Zylstra et al., 1997).
Foto nke 5. Nhazi mkpụrụ ndụ ihe nketa na ụdị dị iche iche a hụrụ n'oge mbibi naphthalene n'etiti ụdị nje bacteria; (A) Ụzọ naphthalene dị elu, metabolism nke naphthalene gaa na salicylic acid; (B) Ụzọ naphthalene dị ala, salicylic acid site na catechol gaa na ụzọ carbon dị n'etiti; (C) salicylic acid site na gentisate gaa na ụzọ carbon dị n'etiti.
"Ụzọ dị ala" (sal operon) na-abụkarị nahGTHINLMOKJ ma na-agbanwe salicylate ka ọ bụrụ pyruvate na acetaldehyde site na ụzọ catechol metaring cleavage. A chọpụtara na mkpụrụ ndụ ihe nketa nahG (nke na-etinye salicylate hydroxylase) echekwara na njedebe dị nso nke operon (Fig. 5B). Ma e jiri ya tụnyere ụdị naphthalene ndị ọzọ na-emebi emebi, na P. putida CSV86 nah nah na sal operons bụ ndị nwere njikọ chiri anya ma nwee njikọ chiri anya (ihe dị ka 7.5 kb). Na ụfọdụ nje bacteria Gram-negative, dị ka Ralstonia sp. U2, Polaromonas naphthalenivorans CJ2, na P. putida AK5, a na-eme ka naphthalene dị ka metabolite carbon etiti site na ụzọ gentisate (n'ụdị sgp/nag operon). A na-egosipụtakarị kaseti mkpụrụ ndụ ihe nketa n'ụdị nagAaGHabAcAdBFCQEDJI, ebe nagR (nke na-etinye koodu nhazi ụdị LysR) dị na njedebe elu (Foto 5C).
Carbaryl na-abanye n'ime okirikiri carbon etiti site na mgbanwe nke 1-naphthol, 1,2-dihydroxynaphthalene, salicylic acid, na gentisic acid (Foto nke 3). Dabere na ọmụmụ mkpụrụ ndụ ihe nketa na metabolic, a tụrụ aro ka e kewaa ụzọ a ka ọ bụrụ "elu" (ntụgharị nke carbaryl ka ọ bụrụ salicylic acid), "etiti" (ntụgharị nke salicylic acid ka ọ bụrụ gentisic acid), na "ala" (ntụgharị nke gentisic acid ka ọ bụrụ etiti ụzọ carbon) (Singh et al., 2013). Nnyocha genomic nke C5pp (supercontig A, 76.3 kb) gosiri na mkpụrụ ndụ ihe nketa mcbACBDEF na-etinye aka na ntụgharị nke carbaryl ka ọ bụrụ salicylic acid, nke mcbIJKL na-esote na ntụgharị nke salicylic acid ka ọ bụrụ gentisic acid, na mcbOQP na ntụgharị nke gentisic acid ka ọ bụrụ etiti carbon (fumarate na pyruvate, Trivedi et al., 2016) (Foto 6).
Akọpụtala na enzymes ndị metụtara mmebi nke aromatic hydrocarbons (gụnyere naphthalene na salicylic acid) nwere ike ibute site na ihe ndị kwekọrọ na ya ma gbochie ha site na isi iyi carbon dị mfe dịka glucose ma ọ bụ organic acids (Shingler, 2003; Phale et al., 2019, 2020). N'ime ụzọ metabolic dị iche iche nke naphthalene na ihe ndị sitere na ya, amụọla atụmatụ nchịkwa nke naphthalene na carbaryl ruo n'ókè ụfọdụ. Maka naphthalene, NahR, onye na-achịkwa trans-action ụdị LysR na-achịkwa mkpụrụ ndụ ihe nketa dị na ma ụzọ elu na ala. Ọ dị mkpa maka mkpali nke mkpụrụ ndụ ihe nketa nah site na salicylic acid na ngosipụta dị elu ya na-esote (Yen na Gunsalus, 1982). Ọzọkwa, ọmụmụ egosila na ihe nnabata integrative (IHF) na XylR (sigma 54-dependent transcriptional regulator) dịkwa oke mkpa maka mkpali transcriptional nke mkpụrụ ndụ ihe nketa na metabolism naphthalene (Ramos et al., 1997). Nnyocha egosila na a na-akpali enzymes nke ụzọ mmeghe catechol meta-ring, ya bụ catechol 2,3-dioxygenase, n'ihu naphthalene na/ma ọ bụ salicylic acid (Basu et al., 2006). Ọmụmụ ihe egosila na a na-akpali enzymes nke ụzọ mmeghe catechol ortho-ring, ya bụ catechol 1,2-dioxygenase, n'ihu benzoic acid na cis,cis-muconate (Parsek et al., 1994; Tover et al., 2001).
N'ime ụdị C5pp, mkpụrụ ndụ ihe nketa ise, mcbG, mcbH, mcbN, mcbR na mcbS, na-akọwapụta ndị na-achịkwa ihe nke ezinụlọ LysR/TetR nke ndị na-achịkwa ihe ndekọ ihe ndị na-ahụ maka ijikwa mmebi carbaryl. A chọpụtara na mkpụrụ ndụ ihe nketa homologous mcbG nwere njikọ chiri anya na onye na-achịkwa ụdị LysR PhnS (mmadụ amino acid 58%) nke metụtara metabolism phenanthrene na Burkholderia RP00725 (Trivedi et al., 2016). A chọpụtara na mkpụrụ ndụ ihe nketa mcbH na-etinye aka na ụzọ etiti (ntụgharị nke salicylic acid gaa na gentisic acid) ma bụrụkwa nke onye na-achịkwa ihe ndekọ LysR NagR/DntR/NahR na Pseudomonas na Burkholderia. A kọrọ na ndị otu ezinụlọ a ghọtara salicylic acid dị ka molekul ihe na-eme ihe kpọmkwem maka mkpali nke mkpụrụ ndụ ihe nketa mmebi. N'aka nke ọzọ, a chọpụtara mkpụrụ ndụ ihe nketa atọ, mcbN, mcbR na mcbS, nke ndị na-achịkwa ụdị LysR na TetR, n'ụzọ dị n'okpuru (metabolites nke ụzọ carbon gentisate-central).
Na prokaryotes, usoro mbufe mkpụrụ ndụ ihe nketa kwụ ọtọ (nnweta, mgbanwe, ma ọ bụ mbufe) site na plasmids, transposons, prophages, genomic islands, na integrative conjugative elements (ICE) bụ isi ihe na-akpata plasticity na nje bacteria genomes, na-eduga na mmụba ma ọ bụ mfu nke ọrụ/àgwà ụfọdụ. Ọ na-enye nje bacteria ohere ịgbanwe ngwa ngwa na ọnọdụ gburugburu ebe obibi dị iche iche, na-enye uru metabolic nwere ike ịgbanwe nye onye ọbịa, dị ka mmebi nke aromatic compounds. A na-enwetakarị mgbanwe metabolic site na nhazi nke degeneration operons, usoro nhazi ha, na enzyme specificitys, nke na-eme ka mmebi nke ọtụtụ ihe aromatic dị mfe (Nojiri et al., 2004; Phale et al., 2019, 2020). A chọpụtala na kaseti mkpụrụ ndụ ihe nketa maka degeneration naphthalene dị na ọtụtụ ihe ndị na-agagharị agagharị dị ka plasmids (conjugative na non-conjugative), transposons, genomes, ICEs, na njikọta nke ụdị nje bacteria dị iche iche (Foto 5). Na Pseudomonas G7, a na-edegharị nah na sal operon nke plasmid NAH7 n'otu ntụzịaka ahụ ma bụrụ akụkụ nke transposon nwere nkwarụ nke chọrọ transposase Tn4653 maka ngagharị (Sota et al., 2006). Na ụdị Pseudomonas NCIB9816-4, a hụrụ mkpụrụ ndụ ihe nketa na plasmid conjugative pDTG1 dị ka operon abụọ (ihe dị ka 15 kb iche) nke e dere n'akụkụ dị iche iche (Dennis na Zylstra, 2004). Na ụdị Pseudomonas putida AK5, plasmid na-abụghị conjugative pAK5 na-akọwapụta enzyme nke na-akpata mbibi naphthalene site na ụzọ gentisate (Izmalkova et al., 2013). N'ime ụdị Pseudomonas PMD-1, nah operon dị na kromozom, ebe sal operon dị na plasmid conjugative pMWD-1 (Zuniga et al., 1981). Agbanyeghị, na Pseudomonas stutzeri AN10, mkpụrụ ndụ ihe nketa naphthalene niile (nah na sal operon) dị na kromozom ma a na-ewere ha site na mgbanwe, njikọtaghachi, na mgbanwe (Bosch et al., 2000). Na Pseudomonas sp. CSV86, nah nah na sal operon dị na genome n'ụdị ICE (ICECSV86). A na-echekwa ihe owuwu ahụ site na tRNAGly, nke na-esochikwa ugboro ugboro kpọmkwem nke na-egosi ebe njikọta/njikọ (attR na attL) na njikọta dị ka phage dị na nsọtụ abụọ nke tRNAGly, si otú a yie ihe ICEclc (ICEclcB13 na Pseudomonas knackmusii maka mbibi chlorocatechol). Akọpụtala na enwere ike ibufe mkpụrụ ndụ ihe nketa na ICE site na njikọta na ugboro nnyefe dị ala (10-8), si otú a na-ebufe ihe onwunwe mmebi nye onye nnata (Basu na Phale, 2008; Phale et al., 2019).
Ọtụtụ mkpụrụ ndụ ihe nketa na-akpata mbibi carbaryl dị na plasmids. Arthrobacter sp. RC100 nwere plasmids atọ (pRC1, pRC2 na pRC300) nke plasmids abụọ jikọtara ọnụ, pRC1 na pRC2, na-akọwapụta enzymes ndị na-agbanwe carbaryl ka ọ bụrụ gentisate. N'aka nke ọzọ, enzymes ndị metụtara mgbanwe nke gentisate na metabolites carbon etiti dị na kromozom (Hayaatsu et al., 1999). Nje bacteria nke ụdị Rhizobium. Nje AC100, nke ejiri mee mgbanwe nke carbaryl ka ọ bụrụ 1-naphthol, nwere plasmid pAC200, nke na-ebu mkpụrụ ndụ ihe nketa cehA nke na-egosi CH dịka akụkụ nke transposon Tnceh nke usoro ihe dị ka ntinye gbara gburugburu (istA na istB) (Hashimoto et al., 2002). N'ụdị Sphingomonas CF06, a kwenyere na mkpụrụ ndụ ihe nketa nke carbaryl dị na plasmids ise: pCF01, pCF02, pCF03, pCF04, na pCF05. Nha DNA nke plasmids ndị a dị elu, na-egosi na e nwere ihe omume mkpụrụ ndụ ihe nketa (Feng et al., 1997). N'ime symbiont nke carbaryl nke mejupụtara ụdị Pseudomonas abụọ, ụdị 50581 nwere plasmid conjugative pCD1 (50 kb) nke na-akọwa mkpụrụ ndụ ihe nketa carbaryl hydrolase mcd, ebe plasmid conjugative na ụdị 50552 na-akọwa enzyme 1-naphthol-degrading (Chapalamadugu na Chaudhry, 1991). Na ụdị Achromobacter WM111, mkpụrụ ndụ ihe nketa mcd furadan hydrolase dị na plasmid 100 kb (pPDL11). A gosila na mkpụrụ ndụ ihe nketa a dị na plasmids dị iche iche (100, 105, 115 ma ọ bụ 124 kb) na nje bacteria dị iche iche sitere na mpaghara dị iche iche (Parekh et al., 1995). Na Pseudomonas sp. C5pp, mkpụrụ ndụ ihe nketa niile na-akpata mbibi carbaryl dị na mkpụrụ ndụ ihe nketa nke na-agafe 76.3 kb nke usoro (Trivedi et al., 2016). Nyocha mkpụrụ ndụ ihe nketa (6.15 Mb) kpughere ọnụnọ nke 42 MGE na GEI 36, nke 17 MGE dị na supercontig A (76.3 kb) yana nkezi ọdịnaya G+C asymmetric (54–60 mol%), na-atụ aro ihe omume mbufe mkpụrụ ndụ ihe nketa kwụ ọtọ (Trivedi et al., 2016). P. putida XWY-1 na-egosipụta nhazi yiri nke mkpụrụ ndụ ihe nketa na-emebi carbaryl, mana mkpụrụ ndụ ihe nketa ndị a dị na plasmid (Zhu et al., 2019).
Na mgbakwunye na arụmọrụ metabolic na ọkwa biochemical na genomic, obere nje na-egosipụtakwa ihe ndị ọzọ ma ọ bụ mmeghachi omume dịka chemotaxis, njirimara mgbanwe elu sel, nhazi nkewa, ojiji preferential, mmepụta biosurfactant, wdg, nke na-enyere ha aka ime ka ihe ndị na-emebi ihe na-esi ísì ụtọ dịkwuo mma na gburugburu ebe ruru unyi (Foto 7).
Foto nke 7. Usoro nzaghachi dị iche iche nke nje bacteria na-emebi hydrocarbon dị mma maka mmebi ihe ndị na-emerụ emerụ nke ọma na ihe ndị na-emetọ ihe si mba ọzọ.
A na-ewere mmeghachi omume chemotactic dị ka ihe ndị na-eme ka mmebi nke ihe ndị na-emebi ihe dị ndụ dịkwuo mma n'ime gburugburu ebe obibi ndị e metọrọ n'ụzọ dị iche iche. (2002) gosiri na chemotaxis nke Pseudomonas sp. G7 gaa na naphthalene mụbara ọnụego mbibi naphthalene na sistemụ mmiri. Ụdị ụdị ọhịa G7 mebiri naphthalene ngwa ngwa karịa ụdị mutant na-enweghị chemotaxis. A chọpụtara na protein NahY (amino acids 538 nwere membrane topology) jikọtara ya na mkpụrụ ndụ ihe nketa ụzọ metacleavage na plasmid NAH7, dịka ndị na-agbanwe chemotaxis, protein a yiri ka ọ na-arụ ọrụ dị ka chemoreceptor maka mmebi naphthalene (Grimm na Harwood 1997). Ọmụmụ ihe ọzọ nke Hansel et al. (2009) gosiri na protein ahụ bụ chemotactic, mana ọnụego mmebi ya dị elu. (2011) gosiri mmeghachi omume kemotactic nke Pseudomonas (P. putida) na gas naphthalene, ebe mgbasa nke gas butere naphthalene na-aga n'ihu na mkpụrụ ndụ, nke na-achịkwa mmeghachi omume kemotactic nke mkpụrụ ndụ. Ndị nchọpụta jiri omume kemotactic a mee ihe iji mepụta nje ndị ga-eme ka ọnụego mmebi dịkwuo elu. Ọmụmụ ihe egosila na ụzọ chemosensory na-achịkwakwa ọrụ sel ndị ọzọ dịka nkewa sel, nhazi okirikiri sel, na nhazi biofilm, si otú a na-enyere aka ijikwa ọnụego mmebi. Agbanyeghị, iji ihe onwunwe a (chemotaxis) maka mmebi dị irè na-egbochi ọtụtụ nsogbu. Ihe mgbochi ndị bụ isi bụ: (a) ndị nnata paralogous dị iche iche na-amata otu ihe mejupụtara/ligands; (b) ịdị adị nke ndị nnata ọzọ, ya bụ, tropism ike; (c) ọdịiche dị mkpa n'usoro na mpaghara mmetụta nke otu ezinụlọ nnata; na (d) enweghị ozi na protein sensọ nje bacteria bụ isi (Ortega et al., 2017; Martin-Mora et al., 2018). Mgbe ụfọdụ, mmebi nke hydrocarbons aromatic na-emepụta ọtụtụ metabolites/intermediates, nke nwere ike ịbụ kemotactic maka otu ìgwè nje bacteria mana ọ na-asọ ndị ọzọ oyi, na-eme ka usoro ahụ sie ike. Iji chọpụta mmekọrịta nke ligands (aromatic hydrocarbons) na ndị na-anabata kemịkalụ, anyị wuru protein sensọ ngwakọ (PcaY, McfR, na NahY) site na ijikọ mpaghara sensọ na akara nke Pseudomonas putida na Escherichia coli, nke na-elekwasị anya na ndị na-anabata maka aromatic acid, TCA intermediates, na naphthalene, n'otu n'otu (Luu et al., 2019).
N'okpuru mmetụta nke naphthalene na polycyclic aromatic hydrocarbons ndị ọzọ (PAHs), nhazi nke akpụkpọ ahụ nje bacteria na iguzosi ike n'ezi ihe nke obere nje bacteria na-agbanwe agbanwe nke ukwuu. Ọmụmụ ihe egosila na naphthalene na-egbochi mmekọrịta nke acyl yinye site na mmekọrịta hydrophobic, si otú a na-eme ka ọzịza na mmiri nke akpụkpọ ahụ dịkwuo elu (Sikkema et al., 1995). Iji lụso mmetụta ọjọọ a ọgụ, nje bacteria na-achịkwa mmiri nke akpụkpọ ahụ site na ịgbanwe oke na nhazi abụba dị n'etiti iso/anteiso branched-chain fatty acids na isomerizing cis-unsaturated fatty acids ka ọ bụrụ trans-isomers kwekọrọ (Heipieper na de Bont, 1994). Na Pseudomonas stutzeri a kụrụ na ọgwụgwọ naphthalene, oke abụba abụba nke jupụtara na nke na-enweghị afọ ojuju mụbara site na 1.1 ruo 2.1, ebe na Pseudomonas JS150 oke a mụbara site na 7.5 ruo 12.0 (Mrozik et al., 2004). Mgbe a na-akọ ya na naphthalene, mkpụrụ ndụ Achromobacter KAs 3–5 gosipụtara mkpokọta mkpụrụ ndụ gburugburu kristal naphthalene na mbelata na chajị elu sel (site na -22.5 ruo -2.5 mV) yana njikọta cytoplasmic na vacuolization, na-egosi mgbanwe na nhazi sel na njirimara elu sel (Mohapatra et al., 2019). Ọ bụ ezie na mgbanwe sel/elu na-ejikọta ozugbo na nnabata ka mma nke ihe na-emetọ aromatic, atụmatụ bioengineering dị mkpa emebeghị nke ọma. Ejighị usoro nhazi nke ụdị sel eme ihe iji melite usoro bayoloji (Volke na Nikel, 2018). Ihichapụ mkpụrụ ndụ ihe nketa na-emetụta nkewa sel na-akpata mgbanwe na nhazi sel. Ihichapụ mkpụrụ ndụ ihe nketa na-emetụta nkewa sel na-akpata mgbanwe na nhazi sel. Na Bacillus subtilis, egosila na protein septum cell SepF na-etinye aka na nhazi septum ma dị mkpa maka usoro ndị ọzọ nke nkewa sel, mana ọ bụghị mkpụrụ ndụ ihe nketa dị mkpa. Mwepụ nke mkpụrụ ndụ ihe nketa nke na-agbanwe peptide glycan hydrolases na Bacillus subtilis butere ogologo mkpụrụ ndụ, mmụba ọnụego uto kpọmkwem, na mmụba ikike mmepụta enzyme (Cui et al., 2018).
A tụpụtara atụmatụ nkewa nke ụzọ mmebi carbaryl iji nweta mmebi dị irè nke ụdị Pseudomonas C5pp na C7 (Kamini et al., 2018). A na-atụ aro ka a na-ebuga carbaryl n'ime oghere periplasmic site na septum nke akpụkpọ ahụ dị n'èzí na/ma ọ bụ site na porin ndị a na-agbasa. CH bụ enzyme periplasmic nke na-eme ka hydrolysis nke carbaryl gaa na 1-naphthol, nke kwụsiri ike karị, hydrophobic karịa ma na-egbu egbu karịa. CH dị na periplasm ma nwee obere njikọ maka carbaryl, si otú a na-achịkwa nhazi nke 1-naphthol, si otú a na-egbochi mkpokọta ya na mkpụrụ ndụ ma na-ebelata nsí ya na mkpụrụ ndụ (Kamini et al., 2018). A na-ebuga 1-naphthol nke si na cytoplasm pụta n'ofe akpụkpọ ahụ dị n'ime site na nkewa na/ma ọ bụ mgbasa, wee bụrụ hydroxylated na 1,2-dihydroxynaphthalene site na enzyme dị elu 1NH maka metabolism ọzọ na ụzọ carbon etiti.
Ọ bụ ezie na obere ihe ndị dị ndụ nwere ikike mkpụrụ ndụ ihe nketa na nke metabolic iji mebie isi mmalite carbon xenobiotic, usoro nhazi nke ojiji ha (ya bụ, iji isi mmalite carbon dị mfe karịa nke mgbagwoju anya) bụ nnukwu ihe mgbochi maka mbibi biodegradation. Ọnụnọ na ojiji nke isi mmalite carbon dị mfe na-ebelata mkpụrụ ndụ ihe nketa na-emepụta enzymes nke na-emebi isi mmalite carbon dị mgbagwoju anya/nke na-anaghị amasị dịka PAHs. Ihe atụ a mụrụ nke ọma bụ na mgbe a na-enye glucose na lactose na Escherichia coli, a na-eji glucose eme ihe nke ọma karịa lactose (Jacob na Monod, 1965). Akọpụtala na Pseudomonas na-emebi ọtụtụ PAH na xenobiotic compounds dị ka isi mmalite carbon. Usoro nhazi nke ojiji isi mmalite carbon na Pseudomonas bụ organic acids > glucose > aromatic compounds (Hylemon na Phibbs, 1972; Collier et al., 1996). Agbanyeghị, enwere ihe dị iche. N'ụzọ na-adọrọ mmasị, Pseudomonas sp. CSV86 na-egosipụta usoro nhazi pụrụ iche nke na-eji hydrocarbons aromatic (benzoic acid, naphthalene, wdg) karịa glucose ma na-eme ka hydrocarbons aromatic na acid organic (Basu et al., 2006). Na nje bacteria a, a naghị achịkwa mkpụrụ ndụ ihe nketa maka mmebi na mbugharị nke hydrocarbons aromatic ọbụlagodi na ọnụnọ nke isi iyi carbon nke abụọ dị ka glucose ma ọ bụ organic acid. Mgbe a na-akụ na glucose na aromatic hydrocarbons medium, a hụrụ na a na-ebelata mkpụrụ ndụ ihe nketa maka mbugharị glucose na metabolism, ejiri aromatic hydrocarbons mee ihe na usoro log mbụ, a na-ejikwa glucose eme ihe na usoro log nke abụọ (Basu et al., 2006; Choudhary et al., 2017). N'aka nke ọzọ, ọnụnọ nke organic acid emetụtaghị ngosipụta nke aromatic hydrocarbon metabolism, yabụ a na-atụ anya na nje bacteria a ga-abụ ụdị nhọrọ maka ọmụmụ biodegradation (Phale et al., 2020).
A maara nke ọma na mgbanwe hydrocarbon nwere ike ibute nrụgide oxidative na mmụba nke enzymes antioxidant na microorganisms. Enweghị ike naphthalene biodegradation ma na mkpụrụ ndụ standalone na ọnụnọ nke ihe ndị na-egbu egbu na-eduga na ịmepụta ụdị oxygen reactive (ROS) (Kang et al. 2006). Ebe ọ bụ na enzymes naphthalene na-emebi emebi nwere ụyọkọ iron-sulfur, n'okpuru nrụgide oxidative, a ga-eme ka iron dị na heme na protein iron-sulfur dị oxidized, na-eduga na enweghị ike ịrụ ọrụ protein. Ferredoxin-NADP+ reductase (Fpr), yana superoxide dismutase (SOD), na-eme ka mmeghachi omume redox a na-agbanwe agbanwe dị n'etiti NADP+/NADPH na molekul abụọ nke ferredoxin ma ọ bụ flavodoxin, si otú a na-ewepụ ROS ma weghachite etiti iron-sulfur n'okpuru nrụgide oxidative (Li et al. 2006). Akọpụtala na nrụgide oxidative nwere ike ịkpalite ma Fpr na SodA (SOD) na Pseudomonas, a hụkwara mmụba nke ọrụ SOD na catalase na ụdị Pseudomonas anọ (O1, W1, As1, na G1) n'oge uto n'okpuru ọnọdụ agbakwunyere naphthalene (Kang et al., 2006). Ọmụmụ ihe egosila na mgbakwunye nke antioxidants dị ka ascorbic acid ma ọ bụ ferrous iron (Fe2+) nwere ike ịbawanye ọnụego uto nke naphthalene. Mgbe Rhodococcus erythropolis toro na naphthalene medium, a mụbara ntụgharị nke mkpụrụ ndụ ihe nketa cytochrome P450 metụtara nrụgide oxidative gụnyere sodA (Fe/Mn superoxide dismutase), sodC (Cu/Zn superoxide dismutase), na recA (Sazykin et al., 2019). Nnyocha proteomic nke tụnyere nke mkpụrụ ndụ Pseudomonas a zụlitere na naphthalene gosiri na mmụba nke protein dị iche iche metụtara nzaghachi nrụgide oxidative bụ atụmatụ ịnagide nrụgide (Herbst et al., 2013).
Akọpụtala na obere ihe ndị dị ndụ na-emepụta ihe ndị na-eme ka ihe dị ndụ dị ndụ n'okpuru ọrụ nke isi iyi carbon hydrophobic. Ndị a bụ ihe ndị na-eme ka ihe dị ndụ dị ndụ bụ ihe ndị nwere ike ịmepụta ihe ndị a na-akpọ "amphiphilic surface active compounds" nke nwere ike ịmepụta ihe ndị a na-akpọ "collections" na mmanụ ma ọ bụ ikuku na mmiri. Nke a na-akwalite mmetọ mmiri ma na-eme ka mmịpụta nke hydrocarbons aromatic dị mfe, na-ebute mmebi mmiri dị irè (Rahman et al., 2002). N'ihi ihe ndị a, a na-ejikarị ihe ndị na-eme ka ihe dị ndụ dị ndụ eme ihe n'ọtụtụ ụlọ ọrụ dị iche iche. Ịtinye ihe ndị na-eme ka ihe dị ndụ dị ndụ ma ọ bụ ihe ndị na-eme ka ihe dị ndụ dị ndụ na-eme ka ihe dị ndụ dị ndụ dịkwuo mma. N'ime ihe ndị na-eme ka ihe dị ndụ dị ndụ, a mụọla ma kọwaa rhamnolipids nke Pseudomonas aeruginosa mepụtara nke ọma (Hisatsuka et al., 1971; Rahman et al., 2002). Ọzọkwa, ụdị biosurfactants ndị ọzọ gụnyere lipopeptides (mucins sitere na Pseudomonas fluorescens), emulsifier 378 (site na Pseudomonas fluorescens) (Rosenberg na Ron, 1999), trehalose disaccharide lipids sitere na Rhodococcus (Ramdahl, 1985), lichenin sitere na Bacillus (Saraswathy na Hallberg, 2002), na surfactant sitere na Bacillus subtilis (Siegmund na Wagner, 1991) na Bacillus amyloliquefaciens (Zhi et al., 2017). Egosipụtala na surfactants ndị a dị ike na-ebelata nrụgide elu site na 72 dynes/cm ruo ihe na-erughị 30 dynes/cm, na-enye ohere maka mmịpụta hydrocarbon ka mma. Akọpụtala na Pseudomonas, Bacillus, Rhodococcus, Burkholderia na ụdị nje bacteria ndị ọzọ nwere ike imepụta ọtụtụ biosurfactants dabere na rhamnolipid na glycolipid mgbe a kụrụ ha na naphthalene na methylnaphthalene media (Kanga et al., 1997; Puntus et al., 2005). Pseudomonas maltophilia CSV89 nwere ike imepụta biosurfactant extracellular Biosur-Pm mgbe a kụrụ ya na ihe ndị na-esi ísì ụtọ dị ka naphthoic acid (Phale et al., 1995). Kinetics nke nhazi Biosur-Pm gosiri na njikọ ya bụ usoro uto na pH dabere na ya. Achọpụtara na ọnụọgụ Biosur-Pm nke mkpụrụ ndụ mepụtara na pH na-anọpụ iche dị elu karịa nke na pH 8.5. Mkpụrụ ndụ ndị toro na pH 8.5 bụ hydrophobic karịa ma nwee njikọ dị elu maka ihe ndị na-esi ísì ụtọ na aliphatic karịa mkpụrụ ndụ ndị toro na pH 7.0. Na Rhodococcus spp. N6, oke carbon ka ọ dị elu site na nitrogen (C:N) na mmachi ígwè bụ ọnọdụ kacha mma maka mmepụta nke biosurfactants sitere na extracellular (Mutalik et al., 2008). Emeela mgbalị iji melite biosynthesis nke biosurfactants (surfactants) site na imeziwanye ụdị na ịgbaze. Agbanyeghị, titer nke surfactant na usoro ọdịbendị dị ala (1.0 g/L), nke na-eweta ihe ịma aka maka mmepụta buru ibu (Jiao et al., 2017; Wu et al., 2019). Ya mere, ejirila ụzọ injinia mkpụrụ ndụ ihe nketa iji melite biosynthesis ya. Agbanyeghị, mgbanwe injinia ya siri ike n'ihi nnukwu nha nke operon (ihe dị ka 25 kb) na nhazi biosynthesis dị mgbagwoju anya nke sistemụ mmetụta quorum (Jiao et al., 2017; Wu et al., 2019). E meela ọtụtụ mgbanwe na injinịa mkpụrụ ndụ ihe nketa na nje bacteria Bacillus, nke bụ isi ebumnuche ya bụ ịbawanye mmepụta surfactin site na dochie promoter (srfA operon), na-egosipụta oke protein mbupụ surfactin YerP na ihe ndị na-achịkwa ComX na PhrC (Jiao et al., 2017). Agbanyeghị, ụzọ injinịa mkpụrụ ndụ ihe nketa ndị a enwetala naanị otu ma ọ bụ ole na ole mgbanwe mkpụrụ ndụ ihe nketa ma erutebeghị mmepụta azụmaahịa. Ya mere, ọmụmụ ihe ọzọ nke ụzọ njikarịcha dabere na ihe ọmụma dị mkpa.
A na-eme nnyocha gbasara mbibi ihe mkpofu nke PAH n'okpuru ọnọdụ ụlọ nyocha ọkọlọtọ. Agbanyeghị, n'ebe ndị ruru unyi ma ọ bụ n'ebe ndị ruru unyi, ọtụtụ ihe ndị na-adịghị arụ ọrụ nke ọma na ihe ndị na-akpata ihe mkpofu (okpomọkụ, pH, oxygen, nnweta nri, nnweta ihe ndị dị n'okpuru ala, ihe ndị ọzọ na-egbochi ihe mkpofu, wdg) egosila na ha na-agbanwe ma na-emetụta ikike mmebi nke ihe ndị dị ndụ.
Okpomọkụ nwere mmetụta dị ukwuu na mmebi PAH. Ka okpomọkụ na-abawanye, ntinye oxygen agbazere na-ebelata, nke na-emetụta metabolism nke obere nje aerobic, ebe ọ bụ na ha chọrọ oxygen molekul dị ka otu n'ime ihe ndị na-eme oxygenases nke na-eme mmeghachi omume hydroxylation ma ọ bụ ring cleavage. A na-ahụkarị na okpomọkụ dị elu na-eme ka ndị nne na nna PAH bụrụ ihe ndị na-egbu egbu karị, si otú a na-egbochi mmebi biodegradation (Muller et al., 1998).
A marala na ọtụtụ ebe ndị PAH metọrọ nwere oke pH dị elu, dịka ebe ndị e metọrọ site na mmiri mmiri acid mine (pH 1–4) na ebe gas/kol eke nke e metọrọ site na alkaline leachate (pH 8–12). Ọnọdụ ndị a nwere ike imetụta usoro mmebi ahụ nke ukwuu. Ya mere, tupu ejiri obere nje mee ihe maka ọgwụgwọ, a na-atụ aro ka ị gbanwee pH site na ịgbakwunye kemịkalụ kwesịrị ekwesị (nwere obere ikike mbelata oxidation) dị ka ammonium sulfate ma ọ bụ ammonium nitrate maka ala alkaline ma ọ bụ liming na calcium carbonate ma ọ bụ magnesium carbonate maka ebe acidic (Bowlen et al. 1995; Gupta na Sar 2020).
Ọkụ oxygen na mpaghara ahụ metụtara bụ ihe na-egbochi ọnụego nke mmebi mmiri PAH. N'ihi ọnọdụ redox nke gburugburu ebe obibi, usoro ọgwụgwọ mmiri in situ na-achọkarị ntinye oxygen site na isi mmalite mpụga (ịkụ ala, ikuku na-efe efe, na mgbakwunye kemịkalụ) (Pardieck et al., 1992). Odenkranz et al. (1996) gosipụtara na mgbakwunye nke magnesium peroxide (ihe na-ewepụta oxygen) na aquifer ruru unyi nwere ike imeziwanye ngwakọta BTEX nke ọma. Ọmụmụ ihe ọzọ nyochachara mmebi mmiri phenol na BTEX n'ime aquifer ruru unyi site na ịgbanye sodium nitrate na iwu olulu mmiri mwepụta iji nweta ọgwụgwọ mmiri dị irè (Bewley na Webb, 2001).