High efficiency degradation of alkanes and crude oil by a salt-tolerant bacterium Dietzia species CN-3

A bacterial strain , CN-3, was isolated from petroleum-contaminated sediment in Bohai Bay, China. Morphological, physiological and phylogenetic analyses indicated that the strain belonged to the genus Dietzia . It was capable of utilizing a wide range of alkanes (C 14 –C 31 ), aromatic compounds and crude oil as the sole carbon and energy sources. The bacterium showed high degradation rate (>80%) of the saturated hydrocarbons of crude oil in the pH range of 6–9. The degradation rate was hardly affected at a NaCl concentration up to 85 g L −1 , indicating that the strain can tolerate high salinities . The real-time quantitative Polymerase Chain Reaction (PCR) results showed that the CYP153 genes could be significantly induced by C 14 , C 15 , C 16 , C 26 and pristane, whereas the transcription level of alk B gene was increased moderately with C 14 , C 15 , C 16 , C 26 and pristane induction condition. A high degradation extent, wide substrate range and facile conditions enhanced the potential for this bacterial strain to be used in the bioremediation of crude oil pollution.