Studies On Lytic Characterization Of Microcystis Aeruginosa By Algicidal Bacterium H1 And Multiple Algicidal Microorganisms

Recently, eutrophication and harmful algae blooms have become increasingly severe in our country. As a result, aquatic environment and aquatic ecological safety have been greatly endangered. The use of algicidal bacteria to control algal blooms attracted many concern while the physical, chemical and other biological methods are not good at removing algae. In this paper, Microcystis aeruginosa, which is the main components in algae blooms, and algicidal bacteria H1, which has a significant effect in the degradation of Microcystis aeruginosa, were selected as research objective to study the algae-lysing characterization of Microcystis aeruginosa by algicidal bacterium H1. Meanwhile, the lytic effect of multiple algicidal microorganisms with different formula was studied.The algae-lysing characteristics of the bacteria H1 against Microcystis aeruginosa showed that it had a significant degradation effect, however, large amounts of N and P would be released to the water after 24～48 h. Bacteria H1 removed algae by not directly but secreting metabolites which participated in the degradation reaction of Microcystis aeruginosa. The metabolites were hydrophilic and could bear high temperature. The algae-lysing effect was promoted by the increase of cultivation time of bacteria H1 and was weakened by the growth of Microcystis aeruginosa. Bacteria H1 had the most significant degradation effect against Microcystis aeruginosa which was in its initial stage of growth while bacteria H1 in its steady growth period had a better degradation effect compared to bacteria H1 in its growth period.Reasearch on multiple algicidal microorganisms dominated by bacteria H1 showed that multiple algicidal microorganisms combined with bacteria H1 and bacteria D1 would inhibit its lytic effect and this effect would reduce while the bacteria D1 component decreased, multiple algicidal microorganisms combined with bacteria H1 and bacteria K2 had no significant effect on its lytic effect, and multiple algicidal microorganisms combined with bacteria H1 and bacteria T5 would promote its lytic effect and this effect would enhance while bacteria T5 component increased. Meanwhile, the inhibit effect of bacteria D1 was greater than the promote effect of bacteria T5. This study also indicated that the best formula of multiple algicidal microorganisms was bacteria H1 and bacteria T5 mixed with 1:1, and some bacteria K2 can also be added into multiple algicidal microorganisms to strengthen its buffering capacity to the environmental change while in practice.