Comparative impact of cadmium on two phenanthrene-degrading bacteria isolated from cadmium and phenanthrene co-contaminated soil in China

Alcaligenes faecalis strain J08 and Brevundimonas sp. strain X08 were isolated from soils co-contaminated by cadmium (Cd) and polycyclic aromatic hydrocarbons (PAHs) in Northeast China. The two strains of bacteria were identified by phenotypic tests and 16S rDNA. Different Cd treatments (0.01 mM, 0.1 mM, 0.5 mM) showed no significant influence ( p > 0.05) on the biodegradation of phenanthrene by A. faecalis strain J08. Brevundimonas sp. strain X08 also presented no significant differences in the biodegradation of phenanthrene in Cd treatments (0.01 mM, 0.1 mM). The growth of Brevundimonas sp. strain X08 was prohibited significantly ( p < 0.05) by Cd in the concentration of 0.5 mM, but the biodegradation of phenanthrene in this group was not impaired. The specific biodegradation rate of Brevundimonas sp. strain X08 in the 0.5 mM Cd group was significantly ( p < 0.05) higher than rates in other Cd treatments (0 mM, 0.01 mM, 0.1 mM).