Associations of aerobic bacteria capable of decomposing the organochlorine pesticide lindane at a concentration of 0.1 g/L in a mineral medium for 30–180 days were obtained via selection. It was found that the lindane-degrading associations L2-6, L3-6, L4-6, L6-6, and L4-10 were characterized by a low level of species diversity (Shannon index of 1.88–2.46). The associations include representatives of the classes of γ‑Proteobacteria (the genus Pseudomonas) and α-Proteobacteria (the genera Novosphingobium, Sphingoauranticus, Sphingomonas, Tardibacter). It was shown that the total DNA isolated from the bacterial associations of the sixth passage (L2-6, L3-6, L4-6, and L6-6) contained genes with a 98–100% level of similarity with the linABCX genes, which encode the “upper” pathways for aerobic lindane transformation. The bacterial association L4-10 effectively decomposed lindane in a mineral medium (100% destruction of 0.1 and 0.3 g/kg of lindane for 30 and 90 days, respectively) and in model soil systems (78.1–90% destruction of 0.5 g/kg of lindane for 45 days). Molecular-genetic and analytical methods indicated that the L4-10 association decomposed not only lindane but also the byproduct chlorine-organic compounds that form during its metabolism (1,3,4-trichlorobenzene, 2,5-dichlorophenol). Thus, the bacterial associations obtained in this study are of interest for the development of bioremediation technologies for areas contaminated with lindane.
Applied Biochemistry and Microbiology – Springer Journals
Published: Sep 1, 2021
Keywords: bacterial associations; lindane; destruction; lin genes