| Three strains of bacteria were isolated from different eutrophic water bodies. They were numbered G-2, A-8 and L-9 by our lab. In order to ensure their taxonomic status,the morphological, physiological characteristics and Phylogenetic analysis based on 16 S r DNA sequence were used to identify three strains of bacteria. According to the results,the three strains G-2, A-8 and L-9 were respectively identified as Bacillus cereus,Acinetobacter Haemolytius, Leucobacter tardus.The microcystins degradation efficiency of A-8 and L-9 were measured by M9medium(added MC). According to ELISA testing, the strains A-8, L-9 had good biodegradation of microcystins and the removal rates were 30.4% and 41.9%respectively on the third day.The rules of growth and algicidal effects of G-2 and A-8 were also studied,and their algicidal mechanisms were discussed initially.These results indicated that the strains algicidal bacteria removed algae by their metabolite substances, and the metabolite substances secreted by G-2 and A-8 could remain active at high temperature.The initial algal concentrations influence the removal rates of G-2 and A-8 strongly. For G-2 the greater the initial algal concentration the faster the degradation of algal, but the influence of initial algal concentration was weak on algicidal efficiency of A-8. The temperature, illumination and p H also had influence on the algicidal effects. According to the results, the removal rates of G-2 and A-8 were the best at 30 ℃ or 35 ℃. The A-8strain showed the best algicidal effects when were under p H arrange from 7.02 to 9.97,while the G-2 was p H 9.97. The algicidal effects of two strains under different illumination were tested. And the results indicated that the longer of the illumination thefaster the degradation of algal. They also had different lytic effects on more than ten species of Cyanobacteria, such as Nodular, Nostoc, Oscillatoria. |
PDF Full Text Request