一株降解微囊藻毒素的缺陷短波单胞菌的分离鉴定及降解特性研究

从太湖水华腐烂蓝藻中筛选出一株能够降解MC-LR的细菌,将其编号为Q3.经形态、生理生化及16S rRNA基因序列分析鉴定为缺陷短波单胞菌(Brevundimonas diminuta).研究发现,在实验条件下该菌能以MC-LR为唯一碳源和氮源生长;7 d内可将初始浓度为0.96 mg·L-1的MC-LR降解为0.37 mg·L-1,降解效率达到61.5%.同时,本研究首次发现缺陷短波单胞菌能够降解藻毒素,并且在此菌种中扩增出了降解过程的关键基因mlr A,推测该菌可能与已报道的Sphingomonas sp.ACM-3962等菌具有相同的降解机制.

Isolation, identification and characterization of a novel microcystin-degrading bacterium

A novel microcystin-degrading bacterium Q3 is isolated from rotten cyanobacteria of Taihu Lake. According to the analysis of morphology, physiological characteristics, as well as 16S rRNA gene sequencing, it could be identified as Brevundimonas diminuta. This bacterium could use microcystin-LR as the sole carbon and nitrogen sources for growth. More importantly, this bacterium was capable of degrading MCs from the initial concentration of 0.96 mg·L^-1 to 0.37 mg·L^-1 during 7 days of incubation, with The degradation efficiency up to 61.5%. It is the first time to report that Brevundimonas diminuta could effectively degrade MCs. In addition, the mlrA gene, as a key enzyme for MCs degradation, was found and amplified in this strain. These results show that the MCs degradation pathway by Q3 is similar to that of Sphingomonas sp.ACM-3962.