1株溶藻菌的部分生物学特性及溶鱼腥藻作用

Partial Biological Characteristics and Algicidal Activity of an Algicidal Bacterium

从淡水湖泊(武汉东湖)水样中成功筛选出1株具有溶藻特性的细菌,编号为A01.显微镜和电镜观察结果表明,菌株A01形态为杆状,长约1.5μm,宽约0.45μm,无鞭毛结构.革兰氏染色及16S rDNA的分子鉴定结果表明,该菌呈革兰氏阴性,属于不动杆菌属(Acinetobacter sp.).溶藻实验结果表明,菌株A01能有效溶解鱼腥藻(Anabaena eucompacta),向对数生长的鱼腥藻藻液中加入A01培养上清或菌体、并培养7 d后,鱼腥藻培养液的叶绿素a去除率分别为77%和61%.显微观察结果表明,与菌株A01的培养上清共培养3 d后的鱼腥藻细胞几乎都被破坏,而与菌体共孵育5 d后的鱼腥藻细胞才有明显裂解.这些结果表明,不动杆菌菌株A01的溶藻作用主要与其培养上清中的有效成分有关,不动杆菌菌株A01可分泌能有效溶解鱼腥藻的活性物质.

An algicidal bacterium was isolated from freshwater（Lake Donghu in Wuhan） and coded as A01.The morphology of the algicidal bacterium was observed using optical microscope and electron microscopes,the results showed that A01 was rod-shaped,approximately 1.5 μm in length and 0.45 μm in width and with no flagella structure.A01 was Gram-negative and belongs to the family Acinetobacter sp.though identification by Gram＇s staining and 16S rDNA gene analysis.A01 exhibited strong algicidal activity on the bloom-forming cyanobacterium Anabaena eucompacta under laboratory conditions.The removal rate of chlorophyll a after 7-day incubation with the culture supernatant of A01 and thalli were 77% and 61%,respectively.Microscopic observation showed that almost all cyanobacterial cells were destroyed within 3 d of co-incubation with the supernatant of algicidal bacterium,but a mass of the cyanobacterial cell lysis was observed only after 5 d of co-incubation with the thalli of algicidal bacterium.These results indicated that the main algicidal component of A01 was in its culture supernatant.In other words,the strain A01 could secrete algicidal component against Anabaena eucompacta.