| With the rapid development of the national industrialization process, environmental pollution aggravating. With arbitrary emissions of sewage, resulting in the inland and coastal water quality in our country also worse every day. Eutrophication, algal blooms frequently, affected the ecological safety and human health production labor seriously. So it’s urgent to explore the effective ways of inhibiting bloom outbreaks. Based on the physical-chemical or the other biological treatment of water pollution are not ideal, Utilizing algae lysing bacteria removal of algal bloom has become a research hotspot of biological control of algae.The algicidal bacteria often direct isolated from the occurrence of eutrophication in water and it often has a certain of pertinence, but also has an effective control on the algae control, This paper selected two strains of algicidal bacteria preserved by units that separated from Huangdao Shandong and Taihu eutrophic pond of Jiangsu. We get the results through 16Sr DNA sequence and physiological-biochemical identification, they are contained in Achromobacter sp. and Bacillus sp., for the convenience of study they are respectively named Y and T fungi. Based on previous studies, This reasech optimized the culture condition of the two strains and as well as Microcystis aeruginosa at the same time, we studied the algicidal characteristics on common harmful water bloom algal Microcystis aeruginosa and the algae lysing specificity, the mechanism of algicidal and the algicidal substances were also explored. The results were as follow:1、The culture conditions of two algae lysing bacteria are optimized by improving the nutrient medium, table temperature and the PH. Three experimental factors on the effect of two algae lysing bacteria’s growth, using the methods of step control of single factor variables explored the best conditions for the growth of two strains.2、The experimental finds that two strains of algae lysing bacteria Y, T can both strongly inhibit the growth of Microcystis, causing a content decreased of algal chlorophyll significantly, and the removal rate of Microcystis algal as high as 99%.3、In the treatment of two algicidal bacteria Y and T culture solution, the all kinds of chlorophyll fluorescence kinetics parameters of Microcystis aeruginosa Showing a downward trend with the increase of co-culture time with the two kinds of strains. We conjecture that the two bacterial strains Y and T relies on the destruction of Microcystis aeruginosa cell photosynthetic system mechanism, to inhibit algae photosynthesis to reach the algicidal effect.4、Explore the mechanism of action of two strains of algae lysing bacteria, the results show that the mainly lytic factor of two strains are not the bacteria but the extracellular secretion of them. The two strains of algicidal bacteria are both mainly indirect algicidal by secreting extracellular active substrate, while the bacteria cells also have certain inhibition on the growth of Microcystis.5、Two algae lysing bacteria algae lysing belongs to indirect algicidal and the extracellular algae lysing active material has good thermal stability.6、The analysis showed that two strains of algicidal bacteria extracellular inhibitory activity, two strains of algicidal substances are not proteins or nucleic acid compounds. The alpha naphthol reaction of Y strain sterile filtrate was positive shows the formation of lavender purple ring. Because of the variety of furfural derivatives, glucuronic acid and acetone, formic acid and lactic acid were showed similar color of positive reaction, The results show that, there may be carbohydrate in Y strain sterile filtrate. The sterile filtrate of strain T showed negative reaction, suggesting that algicidal substance of bacteria T does not belong to carbohydrate, may be other small molecular material with heat resistance.7、The Y strains algicidal substances with molecular weight less than 3 kDa and the T strains algicidal substances with molecular weight of 5-10 kDa. |
PDF Full Text Request