Biodegradation of an endocrine-disrupting chemical di-n-butyl phthalate by newly isolated Camelimonas sp. and enzymatic properties of its hydrolase

Abstract

An aerobic bacterial strain M11 capable of degrading dibutyl phthalate (DBP) was isolated and identified as Camelimonas sp. This strain could not grow on dialkyl phthalates, including dimethyl, diethyl, dipropyl, dibutyl and dipentyl phthalate, but suspensions of cells could transform these compounds to phthalate via corresponding monoalkyl phthalates. The degradation kinetics of DBP was best fitted by first-order kinetic equation. During growth in Brucella Selective Medium, M11 produced the high amounts of non-DBP-induced intracellular hydrolase in the stationary phase. The DBP hydrolase gene of M11 was cloned, and the recombinant DBP hydrolase had a high optimum degradation temperature (50 °C), and a wide range of pH and temperature stability.