Efficient degradation of dibutyl phthalate and utilization of Phthalic Acid Esters (PAEs) by Acinetobacter species isolated from MSW (Municipal Solid Waste) leachate

Bacteria from the genus Acinetobacter are opportunistic pathogens and cause harm to humans. In this study a new bacterial strain designated as Acinetobacter sp. 33F was isolated from municipal solid waste (MSW) leachate. This bacterium is useful as it degrades and utilizes dibutyl phthalate (DBP) as sole carbon source.  Acinetobacter sp. 33F degraded 82.45% of the initial 2000 mg/L of DBP in minimal salt medium. It degraded 54.36 % of initial DBP in samples collected from phthalate esters contaminated site. Monod model explained the growth kinetics of Acinetobacter sp. 33F. The calculated values of µ_max, K_s and yield were 0.01616 h^-1, 382.92 mg/L and 0.43 respectively. Stoichiometry of DBP degradation suggested that 43 g of microbial biomass was produced for every 100 g DBP consumed. Acinetobacter sp. 33F also grows on Di-Ethyl Phthalate (DEP), Di-Octyl Phthalate (DOP), Benzyl Butyl Phthalate (BBP), Mono-Butyl Phthalate (MBP) and Di–isodecyl Phthalate (DIDP) as sole carbon source. Five genes responsible for phthalate esters (PAEs) degradation were amplified from the genome of Acinetobacter sp. 33F. Acinetobacter sp. 33F can be considered as an important tool for remediation of sites contaminated with phthalate esters.