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.