一株来自水库底泥的溶藻菌G2溶藻特性研究

Algae-lysing characteristics of an algicidal bacterium G2 from reservoir sediment

铜绿微囊藻(Microcystis aeruginosa)可引起藻类水华,其大量繁殖会对水体环境造成严重威胁。微生物除藻技术具有良好的应用前景。从陕西省西安市某水库的底泥中分离出一株对铜绿微囊藻具有溶解作用的菌株G2,经16S rDNA序列分析鉴定为纤维弧菌属(Cellvibrio sp.),GenBank登录号为MW221316,并对G2溶解铜绿微囊藻的可行性进行了研究。结果表明,G2通过分泌胞外物质间接溶藻,稳定期的G2对藻类去除效果最佳;提高G2的投加比例(>10%)有助于提升溶藻效果;G2对温度的变化较敏感,5和25℃时除藻率分别可达(59.42±0.88)%和(63.10±1.42)%,温度高于75℃除藻效果不佳;pH和光照对除藻效果影响不显著,G2具有对酸碱耐受能力强(pH 3~11)的特点。综上,G2能有效地抑制铜绿微囊藻繁殖,可作为一种潜在的控制有害藻华的生物制剂。

Microcystis aeruginosa can cause algal blooms,which has been a serious threat to the water environment.Microbial algae removal is a technology with good application prospects.In this study,we isolated a new algae-dissolving bacterium G2 from the reservoir substrate of Xi'an of Shaanxi Province,identified as Cellvibrio sp.according to 16S rDNA sequence analysis(GenBank accession No.:MW221316),and investigated the feasibility of G2's solubilizing M.aeruginosa.Results show that G2 solubilized algae by secreting extracellular substances indirectly,and it had the best removal effect on algae during the stabiliza-tion period.Increasing G2 dosing ratio(>10%)contributed to the effect of algae dissolution.G2 was sensitive to the change of temperature,and the algae removal rate reached(59.42±0.88)%and(63.10±1.42)%at 5 and 25℃,respectively.The removal ef-ficiency was poor at temperatures higher than 75℃.The pH and light had no significant influences on the algae removal effect,and G2 had strong tolerance to acid and alkali(pH 3−11).In conclusion,G2 can inhibit the growth of M.aeruginosa efficiently,so it is a promising biocontrol agent to mitigate cyanobacterial blooms.