Abstract: A high effective alkane-degradation bacterial strain C18 was isolated from oil-contaminated soil of a refinery, and it was identified as Pseudomonas plecoglossicida based on its morphological feature, biochemical & physiological characteristics and partial 16S sDNA sequence analysis. The ability of degrading n-hexadecane/diesel and growth kinetics of said strain were studied by shaking flask tests. It was found that the optimum conditions for the growth of strain C18 were under 30-37 ℃, system pH=7 and containing 1% NaCl. Even at pH=6-9 and system containing 5% NaCl, its ability to degrade n-hexadecane was still high. The growth kinetics research showed that when the concentration of n-hexadecane was 10-300 mg/L under optimum conditions, Michaelis equation could be acquired by calculation with being 15.22 mg/L and being 11.22 mg/(L·h). Under a diesel concentration of 3 000 mg/L, dominant bacterial strain C18 not only could degrade n-alkanes in diesel fuel effectively, but also could well degrade the cyclanes and aromatic hydrocarbons in diesel fuel within 60 h.

Key words: n-hexadecane, dominant bacteria, degradation performance, degradation kinetics