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 (C14-C31), 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 C14, C15, C16, C26 and pristane, whereas the transcription level of alkB gene was increased moderately with C14, C15, C16, C26 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.