Separation And Algae-lytic Character Of Algae-lysing Bacteria EG₄₆ In Water

Nowadays,it is very important to find an effective method for controlling the algal bloom in a short time.So we investigated the algae-lysing bacteria in this study.The main results were as follows:1.Among 60 bacteria isolated from ladscape water in the decline of algal bloom,strain EG₄₆ showed strong lytic activities.The sequence analysis of 16S rDNA showed that EG₄₆ belonged to Bacillus cereus.It was shown that strain EG₄₆ had no adverse effect on mice by toxicity testing.2.The results showed that EG₄₆ can lyse Phormidium mucicola Naum., Anabaena flos-aquae,Oscillatoria tenuis and Cyclotella sp.obviously. The strain gave lethal effects on cyanobacteria by means of extracelluar products,which were secreted from the logarithmic phase and reached the peak value at the stationary phase.At a concentration of 5×10⁷ cfu/mL, the removal of Phormidium mucicola Naum.was 87.5%after 7 days.3.In our investigations,it was shown that lytic effect of EG₄₆ on Phormidium mucicola Naum.was straightly correlated with illumination, pH,salinity,the concentration of CaCl₂ and NaNO₃ in the medium. Photoperiod(L:D=16 h:8 h),pH 7,4‰NaCl,dense concentrations of CaCl₂ and NaNO₃ can promote the lytic effects of bacteria EG₄₆.4.The experiment showed that EG₄₆ had lytic effect on wild-type algae.So it may be used to control algal bloom of small size pond in the future.