Characterization of the metabolic pathway involved in assimilation of acenaphthene in Acinetobacter sp. strain AGAT-W

Abstract

Utilization of an enrichment technique led to isolation of a bacterium from municipal waste-contaminated soil in which acenaphthene was used as the sole source of carbon and energy. The isolate was identified as Acinetobacter sp. strain AGAT-W based on morphological, nutritional and biochemical characteristics and 16S rRNA sequence analysis. Characterization of metabolites by HPLC and GC-MS suggested hydroxylation of acenaphthene to 1-acenaphthenol, which was subsequently transformed to catechol via acenaphthenequinone, naphthalene-1,8-dicarboxylic acid, 1-naphthoic acid and salicylic acid before entering into the tricarboxylic acid cycle. Detection of key enzymes, viz., 1-acenaphthenol dehydrogenase, salicylaldehyde dehydrogenase and catechol 1,2-dioxygenase, in the cell-free extract of Acinetobacter sp. further supported the proposed degradation pathway. This study proposes a metabolic pathway involved in acenaphthene assimilation in strain AGAT-W.