Isolation and identification of biodegradation ability of alkane-degrading bacteria: Molecular detection and analysis of alkane hydroxylase genes

This study was conducted to characterize and to detect the alkane degradation capacity of the bacterial strain (strain Y9) isolated from the sea mud of the crude oil-polluted Dinghai area in China. A Gramnegative, strictly aerobic, oxidase negative, and catalase positive bacterium, strain Y9 was isolated and identified as Acinetobacter sp. based on its physiological characteristics and its 16S rRNA gene sequence analysis. The 16S rDNA of strain Y9 sequence is 99.8% identical with Acinetobacter venetianus RAG-1T. The Y9 strain had an obligate requirement for NaCl but could not tolerate high salt concentrations. Strain Y9 was able to degrade C9~C22 n-alkanes from diesel oil as the sole carbon source, and the degradation rate was up to 53.28% in 7 days at 30°C, pH 8.0. The concentrations of the initial diesel oil and initial bacteria were 4 and 2% (v/v), respectively. The length of alkane hydroxylase gene (alkB) and CYP153A obtained by PCR are 544 and 864 bp, and displays 84 and 98% with Acinetobacter sp. M-1 and Acinetobacter sp. OC4, respectively.