Περίληψη:
The ability of bacteria to degrade organic pollutants influences their fate in the environment, impact on the other biota and accumulation in the food web. The aim of this study was to evaluate abundance and expression activity of the catabolic genes targeting widespread pollutants, such as polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and hexachloro-cyclohexane (HCH) in the Black Sea water column and sediments. Concentrations of PAHs, PCBs and HCH were determined by gas chromatography (GC) coupled to mass spectrometry (MS) and electron capture (ECD) detectors. bphA1, PAH-RHDα, nahAc, linA and linB that encode biphenyl 2,3 dioxygenase, α-subunits of ring hydroxylating dioxygenases, naphthalene dioxygenase, dehydrochlorinase and halidohydrolase correspondently were quantified by quantitative PCR. More recalcitrant PAHs, PCBs and HCH tended to accumulate in the Black Sea environments. In water samples, 3- and 4-ringed PAHs outnumbered naphthalene, while PAHs with > 4 rings prevailed in the sediments. Congeners with 4–8 chlorines with ortho-position of the substituents were the most abundant among the PCBs. β-HCH was determined at highest concentration in water samples, and total amount of HCH exceeded its legacy Environmental Quality Standard value. bphA1, was the most numerous gene in water layers (105 copies/mL) and sediments (105 copies/mg), followed by linB and PAH-RHDα genes (103 copies/mL; 105 copies/mg). The least abundant genes were linA (103 copies/mL; 104 copies/mg) and nahAc (102 copies/mL; 104 copies/mg). The most widely distributed gene bphА1 was one of the least expressed (10−3-10−2 copies/mL; 10−1 copies/mg). The most actively expressed genes were linB (101-102 copies/mL; 103 copies/mg), PAH-RHDα (101 copies/mL; 102 copies/mg) and linA (10−1-100 copies/mL; 100 copies/mg). Interaction of bacteria with PAHs, PCBs and HCH is evidenced by high copy numbers of the catabolic genes that initiate their degradation. More persistent compounds, such as high-molecular weight PAHs or β-HCH are accumulating in the Black Sea water and sediments, albeit microbial activity is directed against them. © 2022
Συγγραφείς:
Prekrasna, I.
Pavlovska, M.
Oleinik, I.
Dykyi, E.
Slobodnik, J.
Alygizakis, N.
Solomenko, L.
Stoica, E.
Λέξεις-κλειδιά:
chlorine; dioxygenase; hexachlorocyclohexane; naphthalene; polychlorinated biphenyl; polycyclic aromatic hydrocarbon; protein biphenyl 2,3 dioxygenase; protein dehydrochlorinase; protein halidohydrolase; protein naphthalene dioxygenase; unclassified drug, Article; Black Sea; bphA1 gene; concentration (parameter); copy number variation; DNA degradation; electron capture detection; gas chromatography; gene; gene expression; genetic code; linA gene; linB gene; marine environment; mass spectrometry; microbial activity; microbial community; microbial interaction; molecular weight; nahAc gene; nonhuman; PAH RHD alpha gene; persistent organic pollutant; polymerase chain reaction; sea pollution; sea surface waters; water sampling
