滇池底泥微生物菌群对微囊藻毒素的生物降解

Biodegradation of microcystins by bacterial community enriched from the sediment of Dianchi Lake

采用滇池水华蓝藻中提取提纯的微囊藻毒素(m icrocystins,MCs)作为微生物生长的碳源和氮源,从长期暴露于蓝藻水华的滇池底泥中,通过从含低浓度到高浓度MCs的逐步培养驯化,获得了高效降解MCs的微生物混合菌群,在初始MC-RR和LR浓度大约分别为50 mg/L和30 mg/L下,3 d内可将MCs全部降解。进一步活性研究显示,不同含碳和含氮化合物虽然能够促进混合微生物菌群的生长,但对降解MCs却无明显的促进作用,说明MCs既可以作为微生物生长的碳源,又可以作为微生物生长的氮源,在富含有机物的天然水体中并不一定能够促进微生物对MCs的生物降解。

The bacterial community in the sediment of Dianchi Lake, which can biodegrade microcystins, was enriched with the methods of using extracted and purified MCs as the carbon and nitrogen sources from low to high concentrations of MCs in the culture medium for a long time. MC-RR and LR with each initial concentration of about 50 mg/L and 30 mg/L were completely biodegraded by this bacterial community in 3 d. It showed that the growth of this bacterial community was promoted however the biodegradation of MCs could not be improved in the presences of other various of carbon and nitrogen containing compounds, which indicated that MCs could be used as both the carbon and the nitrogen sources for the growth of this bacterial community, and the presence of other organic compounds can not promote the biodegradation of MCs in natural water bodies.