溶藻细菌DC-L5的分离、鉴定及其溶藻特性  

ISOLATION,IDENTIFICATION AND CHARACTERIZATION OF A STRAIN OF BLUE-GREEN ALGAE-LYSING BACTERIUM FROM LAKE DIANCHI

作　　者：卢兰兰[1,2] 李根保[1] 沈银武[1] 胡明明[1,2] 刘永定[1] 

机构地区：[1]中国科学院水生生物研究所,武汉430072 [2]中国科学院研究生院,北京100049

出　　处：《水生生物学报》2009年第5期860-865,共6页Acta Hydrobiologica Sinica

基　　金：863课题(编号:2005AA60101504);973项目(编号:2002CB412300)资助

摘　　要：从滇池蓝藻水华集聚区分离获得一株溶藻细菌DC-L5,通过形态及16S rDNA测序分析鉴定为短小芽孢杆菌。用小白鼠进行生物安全实验,小白鼠无中毒症状。研究表明当细菌处于对数生长期时溶藻效果最强,共培养5d使铜锈微囊藻的叶绿素a含量下降83.33%,使惠氏微囊藻、绿色微囊藻、水华束丝藻和水华鱼腥藻4种蓝藻叶绿素a下降率最高为67.6%,最低为58.5%,平均为62.25%。离心沉降后,发现沉淀菌体和无菌上清液对铜锈微囊藻都有溶藻效果,但溶藻效果不及原菌液,推测DC-L5可能是通过直接接触使藻细胞凝聚下沉及进一步的生物降解,同时存在抑制藻细胞生长的胞外分泌物。高温热处理后菌液溶藻作用不明显,推测高温可能使菌体或胞外分泌物质失活。In this study, one high-effect algae-lysing bacterium was isolated and purified from Lake Dianchi, which was labled as the strain DC-L5. The effect, host range, biosafety, lysing mechanism and lysing phenomenon of the algae-lysing bacteria were analyzed. Results were as the followings ： The strain was identified as Bacillus pumilus by means of morphological observation and 16S rDNA sequence analysis in the CCTCC （China Center for Type Culture Collection）. Toxicity test with mouse primarily showed that the strain was non-toxic. 4 kinds of DC-L5 cultures of different growth phases were added to Microcystis aeruginosa, and the strongest algae-lytic ability was found in the log phase of DC-L5 cultures, Chlorophyll a contents in culture of Microcystis aeruginosa reduced by 83.33% in 5 days. For the host range experiment, 4 kinds of dominant cyanobacteria in Lake Dianchi was researched, and average reduction rates of Chlorophyll a of 62.25% in cultures of Microcystis viridis, Microcystis wesenbergii, Aphanizomenon flos-aquae and Anabaena flos-aquae was observed with the highest 67.6% and the lowest 58.5% in 4 days respectively. After centrifugation and sedimentation, both the cells of bacteria and the cell-free suspension had strong algae-lytic activity, but the bacteria culture had the strongest algae-lyric activity, so it maybe showed the strain DC-L5 could directly cause the cyanobacterial cells agglomerated, sinked down and further lysed while the strain could excrete extra-cellular substances able to lyse cyanobacterial cells. In order to improve the algae-lytic activity of the strain DC-L5 to nature bloom, the bacteria cultures were added to nature cyanobacterial bloom dominant with Microcystis aeruginosa, which were sampled from Lake Dianchi and cultured in the lab. The result of nature bloom experiment showed the strain DC-L5 firstly disaggregated the cyanobacterial colony, reduced the floatability, degraded the pigments and then released inclusions of algal cells.

关 键 词：溶藻细菌 生物控藻 芽孢杆菌 蓝藻水华 微囊藻 

分 类 号：X172[环境科学与工程—环境科学]