[Biodegradation of o-chlorophenol by photosynthetic bacteria under co-metabolism]

Photosynthetic bacterial strain PSB-1D cannot utilize o-chlorophenol (2-CP) as the sole carbon source for energy. In this paper, different carbon sources (malic acid, sodium propionate, sodium acetate, sodium citrate, phenol, glucose, and soluble starch) were taken as the co-metabolism substrates to study their effects on PSB-1D growth and 2-CP degradation under the condition of aerobic culture in darkness. Among the substrates, glucose was most efficient, which promoted the reproduction of PSB-1D, enhanced the 2-CP degradation efficiency, and shortened the degradation period. The optimization experiment of added concentration of glucose showed that when the added glucose concentration was 3 g x L(-1), the PSB-1D cell concentration deltaD560 after 168 h culture was 1.749, the half-time of 2-CP was shortened to 3.9 d, and the degradation rate constant was increased to 0.00864 h(-1). The SDS-PAGE analysis on the total microbial cellular protein showed that taking glucose as the co-metabolism substrate, PSB-1D could induce a specific 2-CP-degrading enzyme.