共代谢条件下光合细菌对2-氯苯酚的生物降解

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

光合细菌PSB-1D不能利用2-氯苯酚(2-CP)作为唯一的碳源和能源.选用苹果酸、丙酸钠、乙酸钠、柠檬酸钠、苯酚、葡萄糖和可溶性淀粉等7种不同碳源作为光合细菌PSB-1D降解2-CP的共代谢基质,考察了在黑暗好氧培养条件下,不同共代谢基质对PSB-1D生长及降解2-CP效果的影响.结果表明:葡萄糖能够很好地促进PSB-1D的大量繁殖,提高降解效果,缩短降解周期,为最佳共代谢基质.对葡萄糖的投加浓度进行了优化,当葡萄糖的投加浓度为3g·L-1时,菌株PSB-1D培养168h后的菌体生长浓度ΔD560为1.749,2-CP的半衰期为3.9d,降解速率常数为0.00864h-1.采用SDS-PAGE对微生物全细胞蛋白质进行分析发现,在共代谢过程中当菌株PSB-1D利用葡萄糖作为底物提供能源和碳源时,可诱导产生2-CP特异性降解酶.

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·L-1,the PSB-1D cell concentration ΔD560 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.