溶藻细菌DC21的分离、鉴定及其溶藻特性

从云南滇池中分离得到一株溶藻细菌DC21,经鉴定为葡萄球菌属的1种(Staphylococcussp.),可溶解铜绿微囊等9种藻.试验表明,经过滤、离心沉降及高温灭菌处理的滤液,均能强烈抑制铜绿微囊藻的生长,说明其溶藻作用的因子之一为该菌的胞外分泌物,且这种物质具有热稳定性.细菌DC21使藻的光合作用受到抑制;在试验的第1d,受试藻的超氧物歧化酶及过氧化氢酶活性显著增高,但在第7d,这两种抗氧化保护酶的活性显著下降;受试藻的丙二醛含量明显增高,说明该菌促使其发生了膜脂过氧化.

Isolation, identification and algae-lytic characteristic of a bacterium Staphylococcus sp.

An algae-lytic bacterium DC21, isolated from Lake Dianchi, Yunnan, was identified to be a species belonging to genus Staphylococcus (Staphylococcus sp.). It was able to lyse 9 species of algae, such as cyanobacteria Microcystis aeruginosa (FACHB 905) and Aphanizomenon flos-aquae (FACHB 943), and other 7 species belonging to Cyanophyta and Chlorophyta. The growth of M. aeruginosa was strongly inhibited by the heated bacterium culture, or by the filtrate or the supernate of the bacterial cultures, indicating at least one of the algae-lytic factors produced by this Staphylococcus sp. was extracellular and thermo-stable. In the process of bacterial treatment, the photosynthesis of M. aeruginosa was suppressed intensively; enhancements of superoxide dismutase and catalase activities were detected in the algal cells at the first day of test, however, the pronounced decreases of them were observed on day 7; the malondialdehyde content of the tested algae increased obviously, indicating the lipid peroxidation of the cellular membrane was enhanced by this bacterium.