To Investigate The Regulation Mechanism Of Mycobacteria On Soil Microecology

Myxobacteria are predatory bacteria that are mainly distributed in a variety of soil environments.It can prey on bacteria and fungi through multiple predation mechanisms,and is generally considered to be a key bacterium that regulates the structure and function of soil microbial communities.It is of great practical significance to strengthen the research on the distribution characteristics of myxobacteria in different environments and their regulation and control on soil microecology.In order to explore the regulation mechanism of myxobacteria predation on soil microecology,this paper firstly used high-throughput sequencing technology to carry out community analysis of myxobacteria in 6 different fecal samples,and explored their environmental distribution characteristics in different samples and their effects on other microorganisms.Then the Lawn predation method was used to determine the predatory diameter of 9 species of prey bacteria by myxobacteria EGB to determine its predatory ability to prey bacteria.The high-throughput sequencing technology was used to analyze the changes in microbial community structure caused by myxobacteria predation.At the same time,the signal molecules AHLs were added to deal with myxobacteria EGB,and the effects of AHLs on myxobacteria EGB movement,growth and predation activity were investigated.The main research results are as follows:1)There were significant differences in bacterial diversity in different fecal samples.Except that the bacterial community structure of the two species of wormcast was similar,there were significant differences in bacterial community structure among other fecal samples.There were differences in the richness and diversity of myxobacteria in different fecal samples,and the difference in fecal species was the main reason for the differences in community structure and dominant myxobacteria in different fecal samples.Myxobacteria diversity was significantly correlated with bacterial diversity in fecal samples,and myxobacteria diversity might have an effect on the diversity and distribution of other microorganisms in fecal samples.2)Myxobacteria EGB had significantly different predation ability against 9different prey bacteria,and myxobacteria had significantly higher predation ability against Bacillus tropicalis than other bacteria(P<0.05).Adding unequal myxobacteria to the artificial microcosm system containing 9 kinds of prey bacteria could significantly reduce the diversity index of bacterial community(Shannon).PCo A results showed that myxobacteria predation could affect microcosmic microbial community structure.After cultured for 24 h in the artificial microcosm,the relative abundance of 7 prey bacteria decreased significantly(Lef Se,P<0.05),but the relative abundance of Burkholderia cenocepacia increased significantly(P<0.05).The results of the artificial microcosm experiment showed that the addition of myxobacteria was the main factor affecting the change of microbial community structure,and the addition of the smallest dose of myxobacteria(1 m L)also had a significant effect.With the increase of culture time,Burkholderia cenocepacia is the only prey bacteria that can resist myxobacteria and has high abundance.3)The signal molecule AHLs had no obvious linear rule on colony expansion of myxobacteria EGB.Adding 15 ?M/L AHLs could significantly promote the growth of myxobacteria EGB,and high concentration of AHLs may have a better promoting effect on the growth of myxobacteria.AHLs could promote the predation activity of myxobacteria EGB,but it may be affected by the species of prey,AHLs concentration and medium type.