Research On The Urease Producing Bacterial Population Resources And Their Promoting Growth In Guizhou Karst Topography

The soil in Guizhou karst area has an ancient geological history,and the ecological environment is stable and diverse.The soil in this area is rich in carbonates and has a rich beneficial microbial population.Soil urease plays an important role in soil ecosystems,especially in soil material conversion and energy metabolism.It is also an important indicator for evaluating the quality of ecological environment and soil fertility.Urease is widely used in biochemical engineering,industrial manufacturing and environmental protection,so it has profound significance for the study of urease.In this study,160 soil samples were collected from Guizhou area for the collection of soil samples.The soil environmental information of the sample was collected,the physical and chemical properties of the soil samples were determined,and the soil-developable urease was analyzed by plate dilution coating.The bacteria were counted,and then the effects of karst landform soil on culturable bacteria were investigated.The strains were further identified based on 16SrDNA sequencing,pure culture morphology of colonies,Gram staining and physiological and biochemical tests.On the principle of enzyme-linked reaction,the urease activity of urease-producing bacteria was determined.Finally,four strains with high urease activity were selected,which were QSH003N10(Acinetobacter radioresistens),AL30N1(Bacillus litoralis),AL10N28(Enterobacter aerogenes),QSH003N6(Acinetobacter junii),in turn,studied the growth of maize plants under different bacterial conditions.The results show that the soil moisture content of karst landform in Guizhou is low,the mean value is:14.41%.The soil is rich in Fe,Ca,Ti,K,P Five elements,other elements are less.The soil PH value of five regions was neutral partial alkali,the total average was:7.278,the difference was small.There were significant differences in soil organic matter content in various regions,with a total average of 18.894%.Guizhou Karst geomorphology soil microbial resources and abundant,rich in the number of cultured bacteria about 30-4.47x109,can be cultured"urease production bacteria"content roughly in the 0-9.98x104 cell/g soil,in the cultured flora accounted for roughly in 0-1.01%.The cultured objects isolated from soil in this study were 2238 strains.After the identification of 530 strains of 16SrDNA series,343 strains of urea-producing bacteria were successfully identified,and 25 genera were 79 species.The dominant bacteria were the genus Enterobacter(10 of 12.66%)and the genus Pseudomonas(10 of 12.66%),the genus Bacillus(12 of 15.19%),followed by the genus Bacillus(4 of which accounted for 5.06%).After the comparison sequence and related website,11 strains were found to have no Chinese name,suspected to be a new record.Gram staining was carried out on 79 kinds of urea-producing bacteria,gram staining negative bacteria were 19 species,and gram staining positive bacteria were 60 species.Most of the fungi are rod-shaped,short rodshaped,and less part of the fungus spherical.The PH value,water content,organic matter and environment of karst soil in Guizhou have a great relationship,and the number of bacteria cultured by soil sample is also closely related to the environment.Corn Pot experiment showed that corn plants had significant changes in plant height,leaf width,leaves,fresh dry weight,root length and chlorophyll content after inoculation of AL30N1,QSH003N10,AL10N28 and QSH003N6 bacteria during seedling,and compared with CK,the growth status of inoculation fungi was good,The results of maize seedling and total nutrient solution were not significant,and further verification showed that urea-producing bacteria had a stimulating effect on maize plants.In this study,the soil characteristics of Guizhou karst were analyzed,and the soil characteristics and the beneficial microbial germplasm resources of urease-producing bacteria were analyzed.The karst special landform biological resources are extremely rich,and after preliminary research,it will be beneficial to the development and utilization of beneficial microbial resources.