Inhibition Of Antioxidant Competition On The Growth And Proliferation Of Microcystis Aeruginosa

The phenomenon of bloom in reservoirs,rivers and lakes caused by eutrophication is still very common.Microcystins and other secondary metabolites released by microcystis blooms pose a threat not only to human health,but also to aquatic organisms,seriously affecting the safety of water quality.How to effectively and greenly prevent and control the proliferation and outbreak of algal blooms is a hot issue in the field of environmental research.Biological method is one of the more environmentally friendly methods in algae removal technology,but at present,the existing technology is difficult to implement and the efficiency of algae removal is low.Based on the competition of antioxidant effect between Microcystis and its symbiotic bacteria,this paper makes a preliminary attempt to study the potential of a new algae control technology with high efficiency and environmental protection.the main results are as follows:1)The growth and antioxidant function of Microcystis aeruginosa and its symbiotic bacteria were studied,and the feasibility of this idea was preliminarily confirmed.According to the analysis of microbial diversity,Microcystis aeruginosa coexisted with many species of different genera.KEGG metabolic pathway function prediction analysis showed that the relative abundance of peroxidase metabolic pathway of Microcystis aeruginosa was lower than that of its symbiotic bacteria,which meant that the antioxidant metabolism of Microcystis aeruginosa was weaker than that of its symbiotic bacteria.At the same time,after the addition of antibiotics,except for one strain of Microcystis Wyeth,the growth of Microcystis was inhibited and the growth rate of logarithmic phase slowed down obviously.These results show that the growth of Microcystis aeruginosa can not be separated from symbiotic bacteria.2)The specific inhibitor of catalase was used to explore its inhibitory effect on catalase and its regulatory effect on the growth of Microcystis aeruginosa,and the feasibility of this idea was further verified.it laid a foundation for the subsequent inhibition of the growth of Microcystis aeruginosa based on symbiotic catalase deletion mutants.In the concentration optimization experiment of inhibitors,different concentrations of3-Amino-1,2,4-triazole(ATZ)were added to the experimental group.The results showed that the growth of algae was inhibited in the logarithmic phase,and the inhibitory effect was enhanced with the increase of ATZ concentration.The results of inhibition experiment showed that the catalase activity of the flora decreased significantly,the antioxidant capacity of the flora was affected,and the level of reactive oxygen species in the environment increased,which inhibited the normal growth of algae cells.From the species abundance clustering heat map,it was further seen that after the inhibition of ATZ,the abundance of symbiotic bacteria decreased at first,then significantly increased,and the abundance of algae also significantly decreased.Symbiotic bacteria propagated in large numbers to resist oxidative stress and maintain the antioxidant balance of the flora.3)The kat B deletion mutant of Pseudomonas aeruginosa was successfully constructed,which made the mutant lose the ability to encode catalase.The inhibitory effect of the mutant on the growth of Microcystis aeruginosa provided theoretical proof for a new idea of algae inhibition.The effect of mutants on the growth of Microcystis aeruginosa was studied under different inoculum size.The results showed that the growth of Microcystis aeruginosa in the experimental group was significantly inhibited,and the inhibitory effect was enhanced with the increase of inoculation amount.