Abstract: The growth of three salt-tolerant bacterial strains (Microbacterium sp. S1, Zhihengliuella sp. G12 and Pseudomon asputida Y3) was investigated in inorganic salt media containing naphthalene, phenanthrene, retene or benzo [α] pyren as the sole carbon source and supplement with glucose at a concentration of 0, 0.5, 1.0, and 1.5 g/L for 7 d and the degradation of polycyclic aromatic hydrocarbons(PAHs) was analyzed by gas chromatography mass spectrometry(GC-MS) in order to probe into the degradation capabilities of three salt-tolerant bacterial strains for different PAHs. The results showed that all of the strains utilized the four kinds of PAHs as carbon sources, with the best growth in the naphthalene containing inorganic salt medium without glucose. Furthermore, the growth of these strains was found to be proportional to the concentration of glucose in the inorganic salt medium containing phenanthrene, retene or benzo [α] pyren, without significant difference among 0.5 g/L group， 1 g/L group and 1.5 g/L group(P>0.05). The maximal PAHs degradation rate was observed in the three strains cultured in the inorganic salt medium containing 1 g/L glucose, with an increase by 44.06% (S1), 70.56% (Y3) and 50.98% (G12) for naphthalene degradation, 49.66% (S1), 45.87% (Y3) and 38.29% (G12) for phenanthrene degradation, 66.13% (S1), 61.31% (Y3) and 56.20% (G12) for retene degradation, and 69.42% (S1), 65.79% (Y3) and 65.01% (G12) for benzo [α] pyren degradation. However, the PAHs degradation efficiency of the single cell was significantly reduced with the increase in glucose concentration. The findings indicate that co-metabolism effect might be involved in the degradation process of the four PAHs by the three strains.
2018, Vol. 33 
