Deciphering the kinetics and pathway of lindane biodegradation by novel soil ascomycete fungi for its implication in bioremediation

Abstract

Lindane, an organochlorine pesticide, negatively affects living beings and the ecosystem. In this study, the potential of 9 Ascomycetes fungi, isolated from an hexachlorocyclohexane dumpsite soil, was tested for biodegradation of lindane. The strain Pleurostoma richardsiae (FN5) showed lindane biodegradation rate constant (K value) of 0.144 d-1 and a half-life of 4.8d. The formation of intermediate metabolites upon lindane degradation including & gamma;-pentachlorocyclohexene, 2,4-dichlorophenol, phenol, benzene, 1,3- cyclohexadiene, and benzoic acid detected by GC-MS and the potential pathway adopted by the novel fungal strain FN5 for lindane biodegradation has been elucidated. The study of gene profiles with reference to linA and linB in strain FN5 confirmed the same protein family with the reported heterologs from other fungal strains in the NCBI database. This study for the first time provides a thorough understanding of lindane biodegradation by a novel soil-borne Ascomycota fungal strain for its possible application in field-scale bioremediation.