摘要
从巢湖沉积物中分离出1株MC高效降解菌，命名为CH菌．根据16SrRNA基因序列分析结果，初步确定该菌为Paucibacter sp．．该菌能以MCLR为唯一碳源和能源生长，并且在10h内可将11．6μg·mL^-1的MCLR降解至检测限以下，其一级反应速率常数为0．242h^-1．CH菌降解MCLR的适宜温度为25～30℃，适宜pH为6～9．MCLR降解过程中产生1种含有Adda残基的中间产物，该产物与已报道的ACM-3962菌的降解产物不同，并且反应过程积累终产物Adda．在菌株CH中未检测到mlrA、mlrB、mlrC和mlrD这4个MC降解基因的同源基因．这些结果表明，Paucibactersp．CH菌降解MC的机制不同于已知的ACM-3962菌的降解机制．
A bacterium capable of degrading microcystin （MC） , strain CH, was isolated from the sediment of Lake Chaohu, China. Strain CH was tentatively identified as Paucibacter sp. based on the analysis of 16S rRNA gene sequences. Paucibacter sp. strain CH can use microcystin LR （MCLR） as the sole carbon and energy sources, and 11.6 μg·mL-1 of MCLR was degraded to below the detection limit within 10 hours with the first-order reaction rate constant of 0. 242 h^-1. The optimum temperature and initial pH for MC degradation were 25-30℃ and pH 6-9, respectively. A novel intermediate product containing the Adda residue was detected during the degradation of MCLR, which is different from those produced by strain ACM-3962, and Adda was recognized as the final product of the degradation process. Furthermore, no homologue to any of the four genes, mlrA, mlrB, mlrC and mlrD previously associated with the degradation of MCLR by strain ACM-3962 was found in strain CH. These findings suggest that Paucibacter sp. strain CH might degrade MC through a different pathway from that of strain ACM-3962.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2014年第1期313-318,共6页
Environmental Science
基金
国家自然科学基金项目(21077083)
中央高校基本科研业务费专项(2012-Ⅳ-095)
