环洞庭湖四个淡水湖渔场底泥产几丁质酶细菌的筛选鉴定、分布和产酶量研究

Screening,Identification,Distribution and Enzyme Production of Chitinase-Producing Bacteria from the Sediments in Fishing Grounds of Four Freshwater Lakes around Dongting Lake

为了解淡水湖渔场底泥中产几丁质酶菌株的产酶量和分布情况,对环洞庭湖的4个淡水湖渔场的表层底泥样品进行了无菌采集。利用稀释涂布平板法、点种法和摇瓶发酵法从底泥样品中筛选分离到26株产几丁质酶菌株,几丁质酶活在0.07~0.69 U/mL之间。对26株产几丁质酶菌株进行16S rRNA基因鉴定和系统发育分析。结果表明,26株菌株都分布于变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)的芽胞杆菌属(Bacillus)、假单胞菌属(Pseudomonas)、不动杆菌属(Acinetobacter)和微小杆菌属(Exiguobacterium)。且产几丁质酶细菌在4个淡水湖渔场表层底泥中的分布情况为安乐湖>东湖>北民湖>西湖。对产几丁质酶菌株的降解活力、种类组成及数量分布的研究可为淡水湖渔场底泥中产几丁质酶微生物资源的开发及应用提供参考。

In order to understand enzyme production and distribution of chitinase-producing bacteria from the sediments in fishing grounds of four freshwater lakes around Dongting Lake,the surface sediment samples were collected aseptically.Twenty-six chitinase-producing bacteria were screened and isolated from the sediment samples adopting dilution spread plate method,spot inoculation method,and shaking flask fermentation methods.The chitinase activity ranged from 0.07 to 0.69 U/mL.16S rRNA gene identification and phylogenetic analysis showed that 26 chitinase-producing bacteria were all distributed in Proteobacteria and Firmicutes,belonging to the genus of Bacillus,Pseudomonas,Acinetobacter,and Exiguobacterium.The quantity distribution of chitinase-producing bacteria from the surface sediments in fishing grounds of four freshwater lakes is as follows:Anle Lake in Hanshou County>East Lake in Huarong County>Beimin Lake in Li County>West Lake in Jinshi City.The study on the degradation activity,species composition and quantity distribution of chitinase-producing strains can lay a theoretical foundation for the exploitation and application of chitinase-producing microbial resources from the sediments in fishing grounds of freshwater lakes.