Study Of Microecosystem On Microcystis Aeruginosa And Aerobic Bacteria

Water eutrophication caused by water pollution lead to increasingly serious water blooms, which bring serious harm and economic loss on drinking water resources and aquaculture, and bring some threat to the health of people. On the microalgae bloom control, in addition to the traditional physical and chemical methods, in recent years, domestic and foreign scholars began to a lot of research on controlling microalgae outbreak by microorganism, reported in literature, the present research more to study the relationship between algae-lysing bacteria with microalgae. In this paper, on the basis of research at home and abroad, has studied the relationship between non algae-lysing bacteria with Microcystis aeruginosa. This research studied the interaction between the two microorganism, providing some comprehensive and effective fundamental experiment data for microbial method on blooms governance, eutrophication control and so on.In order to explore the change regularity of algae and bacteria biomass and the change rule of dissolved organic matter in different systems, this study built two different algal- bacterial symbiotic system by Microcystis aeruginosa which on the early stage and medium stage of the logarithmic growth with 15# aerobic becteria(Hereinafter referred to as system 1 and system 2).This research monitor the content of chlorophyll a,the number of bacteria, dissolved organic carbon and dissolved organic matter by the UV spectrophotometry, microscope counting method, combustion oxidation- non-dispersive infrared absorption method, three-dimensional excitation emission matrix fluorescence spectroscopy, obtained the following conclusions:(1) Through monitoring of algae and bacteria in the system,concluded that in system 1 and system 2 algae would release nutrients which synthesized by photosynthesis to symbiotic environment, bacteria would secrete a substance or produce siderophores transporting trace elements to promote the growth of algae. Algae and bacteria in the symbiotic system compete limited nutrients to maintain their growth or secrete metabolites to the environment to inhibit the growth of other.(2) Through the analysis of dissolved organic matter’s three-dimensional fluorescence spectroscopy, in the two symbiotic system, algae and bacteria are more easy to use tyrosine-like, tryptophan-like and soluble microbial by-product, and fulvic acid-like, humic acid-like can be a small amount of accumulation in the system, not easy to be absorbed. Through the analysis of the total fluorescence intensity of dissolved organic matter found, microorganism will be more use of fluorescent organic matter when it in good growth environment, stable life status,while other phases, it was More easy to absorb the non-fluorescent material.(3) Compared with the system 1,algae in the system 2 shows a greater competitive advantage when competing with the bacteria, which can suppress the growth of bacteria,making the maximum number of bacteria in the system 2 less than the system 1. Algae and bacteria system 2 had a more fierce competition on nutrients, so that some nutrients in system 2 were used more fully.