小麦内生溶藻细菌ZB1的分离鉴定及其溶藻特性

Identification and Algae-lytic Characteristics of Endophyte Algicidal Bacteria ZB 1 Strain Isolated from Wheat

【目的】为蓝藻水华的生物防治提供依据。【方法】以小麦中分离到1株内生细菌ZB1为研究对象,通过混菌法、平板溶藻法及液体溶藻法,考察了该菌株对铜绿微囊藻的溶藻活性。【结果】经形态学特征、生理生化特性及16S r DNA同源性序列分析,鉴定菌株ZB1为纺锤形赖氨酸芽孢杆菌(Lysinibacillus fusiformis)。菌株ZB1对铜绿微囊藻具有强烈的溶藻作用,且溶藻活性随菌液浓度的升高和作用时间的延长而增加;菌株ZB1的发酵原菌液、无菌上清液和高温处理液对铜绿微囊藻均具有溶藻作用,但菌体重悬液无溶藻作用;藻液中加入10%的无菌上清液,受试藻的叶绿素a含量由3.85 mg/L降至0.29 mg/L,除藻率为92.5%;溶藻物质具有热稳定性。【结论】菌株ZB1在蓝藻水华防治方面具有一定的应用价值。

[ Objective ] The present paper aims to provide the basis for biological control of algae bloom. [ Method] The algae-lytic activity of an endophyte bacteria ZB1 strain isolated from wheat against Microcystis aeruginosa was investigated by mixed bacteria, plate algae-lyric and liquid algae-lytic methods. [ Result ] The ZB1 strain is identified as Lysinibaeillus fusiformis by morphological feature, physiologicai-bioehemi- cal property and 16S rDNA homology sequence analysis. The ZB1 strain has a strong algae-lyric effect against Microcystis aeruginosa and the algae-lytic activity of ZB1 strain increases with increase of bacterium concentration and prolongation of action time. The fermentation original solution, sterile supernatant and high-temperature treating solution of ZB1 strain all have the algae-lyric effect but its bacterium resuspension solution has no the algae-lyric effect. The chlorophyll a content ofMicrocystis aeruginosa solution added with 10 % sterile supernatant reduces from 3.85 mg/L to 0.29 mg/L and its algae-lyric rate reaches 92.5 %. The algieidal substance is of a heat stability. [ Conclusion] ZB1 strain has a certain application value in control of algae bloom.