两株溶藻细菌的分离鉴定及其溶藻特性

从富营养化池塘中筛选分离出两株溶藻细菌L7和L18,通过生理生化实验及16SrDNA测序进行鉴定,对其单一以及混合菌液去除铜绿微囊藻(Microcystis aeruginosa)、水华鱼腥藻(Anabaena flos-aquae)的效果进行研究,并考查其溶藻方式。结果表明:菌液的滤液有溶藻效果,溶藻细菌具有间接溶藻特性;细菌需要一定的初始浓度才能有明显的溶藻效果,初始浓度越高,溶藻效果越好;溶藻效果大致趋势为混合菌液>L18>L7;不同生长时期溶藻菌,其滤液的溶藻效果差异很大,衰减期的滤液溶藻效果好于对数生长期和稳定期的;滤液投加体积分数与溶藻效果成正相关;细菌鉴定结果表明,L7为蜡状芽孢杆菌(Bacillus cereus),L18为短小芽孢杆菌(Bacilluspumilus)。

Isolation and Identification of Two Algae-lysing Bacteria and Their Lytic Character

Two algae-lysing bacteria L7 and L18 were isolated from eutrophic pond. The lytic effect and lytic mode of single and mixed bacteria on Microcystis aeruginosa and Anabaena flosaquae were studied respectively. Results showed that the filtrate presented lytic effects, with property of indirect algae-lysing. A certain initial bacteria concentration was needed for bacteria to reach an obvious lytic effect. The higher the initial bacterium concentration was, the more obvious the lytic effect was. Different growth phase had significantly different effect on algae-lytic characters. The decline phase was proved better than log and plateau phase. The lytic effect of bacteria had direct ratio with filtrate volume percent. It was concluded that L7 belonged to Bacillus cereus and L18 belonged to Bacillus pumilus by analysis of biophysics, biochemistry experiment and 16SrDNA sequence.