Characterization of co-metabolic biodegradation of methyl <i>tert</i>-butyl ether by a <i>Acinetobacter</i> sp. strain

Abstract

Co-metabolic bioremediation is a promising approach for the elimination of methyl <i>tert</i>-butyl ether (MTBE), which is a common pollutant found worldwide in ground water. In this paper, a bacterial strain able to co-metabolically degrade MTBE was isolated and named as <i>Acinetobacter</i> sp. SL3 based on 16S rRNA gene sequencing analysis. Strain SL3 could grow on <i>n</i>-alkanes (C₅-C₈) accompanied with the co-metabolic degradation of MTBE. The number of carbons present in the <i>n</i>-alkane substrate significantly influenced the degradation rate of MTBE and accumulation of <i>tert</i>-butyl alcohol (TBA), with <i>n</i>-octane resulting in a higher MTBE degradation rate (<i>V</i> _max = 36.7 nmol min^-1 mg_protein ^-1, <i>K</i> _s = 6.4 mmol L^-1) and lower TBA accumulation rate. A degradation experiment in a fed-batch reactor revealed that the efficiency of MTBE degradation by <i>Acinetobacter</i> sp. strain SL3 did not show an obvious decrease after nine rounds of MTBE replenishment ranging from 0.1-0.5 mmol L^-1. The results of this paper reveal the preferable properties of <i>Acinetobacter</i> sp. SL3 for the bioremediation of MTBE <i>via</i> co-metabolism and leads towards the development of new MTBE elimination technologies.