溶藻细菌DC-L14的分离、鉴定与溶藻特性

Isolation, Identification and Characterization of Blue-green Algae-lysing Strain DC-L14 from Lake Dianchi, China

从滇池蓝藻水华集聚区分离获得一株溶藻细菌DC-L14,经16SrDNA序列分析鉴定为Lysinibacillus fusiformis;小白鼠毒性试验初步显示该菌株未产生小白鼠中毒毒素;该菌能使铜锈微囊藻905聚集成团,沉于瓶底,最终黄化;该菌作用4d,使惠氏微囊藻107、绿色微囊藻102、水华束丝藻和水华鱼腥藻的叶绿素a下降率最高为70.1%,最低为65.5%,平均为67.2%;当细菌处于稳定生长期时溶藻效果最强,共培养4d能使铜锈微囊藻905的叶绿素a含量下降82.1%;离心沉降后检测,发现菌体本身无溶藻效果,而无菌上清液与原菌液溶藻效果相同,高温处理后的菌液溶藻能力增强,推测该细菌是通过分泌溶藻物质溶藻,该物质可能为非蛋白质类,高温可能有利于溶藻物质的释放.

An algae-lysing strain DC-L14 was isolated from an area with dense blue-green algae in Lake Dianchi, southwestern China and it was identified as Lysinibacillusfusiformis based on 16S rDNA sequence analysis. The toxicity test on mouse primarily showed that the strain was non-toxic. Under the laboratory condition, the strain could cause Microcystis aeruginosa cells to agglomerate, sinking to bottom and becoming yellow. The reduction rate of chlorophyll a after 4 days was 67.2% on an average, with the highest of 70.1% and lowest of 65.5% in the cultures of Microcystis viridis, M. wesenbergii, Aphanizomenon flos-aquae and Anabaenaflos-aquae. The strongest algae-tytic ability was found at the stable phase of DC-L14 culture, which could reduce chlorophyll a content of M. aeruginosa by 82.1% in four days. After centrifugation and sedimentation, the cells of bacteria showed no algae-lytic ability, but the cell-free supernatant displayed the same algae-lytic ability as that of the whole bacteria culture, and the heated bacterial culture showed the highest algae-lytic ability, indicating that some extracellular and thermo-stable substances produced by this strain had the algae-lyric ability, and high temperature possibly reinforced the algae-lytic ability. Fig 4, Tab 1, Ref25