Study On Community Structure And Function Of Bacterial In Water And Soil Of Huguangyan

Huguangyan is a volcanic Maar lake, which must have special microbe secreting metabolic products. So Systematically studing the composition of the microbe of the region and diversity of microbial are extremely important on facilitating the extreme environmental microbial resources in the biotechnology industry and providing a theoretical basis in the use of microorganisms of the region for the future and its metabolites in strains.1.Counts and distribution of bacteria in HuguangyanWater sample and soil sample are collected by 4 seasons, November in 2008, March, June, September in 2009. Four sampling points are Huguangyan center island, mudflats, free captive stations and barbecue areas. Heterotrophic bacteria, phosphorus bacteria, nitrifying bacteria, nitrification bacteria and E. coli are measured by colony-forming unit(CFU) and most probable number(MPN) on the count. The results showed that the average total number of heterotrophic bacteria is 1.5×105CFU/ml, the average total number of phosphate solubilizing bacteria is 2.02×105CFU/ml, the average number of nitrifying bacteria and nitrification were 117.7MPN/mL and 8.96MPN/mL. The average total of E.C. is 2663.13 / L. From spatial distribution,the number of heterotrophic bacteria of mudflats Department is at most, center island at least; phosphate solubilizing bacteria in the sediment in the Central Island Department is more, water less; E.C.in water in Centre Island is at least; nitrifying bacteria and nitrification bacteria in all sampling points are less. Generally speaking, microbiology quantitative indicators of Centre Island is the best. From the seasonal distribution, the distribution of heterotrophic bacteria and phosphate solubilizing in the sediment is indiciplined; the distribution of bacteria in the water generally positively correlated with temperature; the number of E.C. in spring are more, less in winter; seasonal difference of nitrifying bacteria and nitrite bacteria was not significant.2. Distribution of diversity index of heterotrophic bacteriathe extent of microbial diversity Huguangyan water is evaluated by Simpson's index (L) and Shannon-wiener index (H). The results showed that: diversity index was highest in spring, lowest in winter; free captive stations and barbecue areas have a high diversity index, center island and mudflats have a lower diversity index. 3.Identification of superior heterotrophic bacteria198 strains of heterotrophic bacteria and 83 strains of phosphorus bacteria separated from Water and sediment from the Huguangyan. According to the morphological characteristics and cultural characteristics of the bacteria initially getting 12 superior heterotrophic bacteria and 3 phosphorus bacteria. Strains are Identified though determination 16S rDNA sequence. 12 strains of heterotrophic bacteria : 5 are Bacillus sp., 2 are Pseudomonas sp., 2 are Stenotrophomonas sp., 1 are Staphylococcus sp.,1 are Exiguobacterium sp.,1 are Enterobacter sp.. 1 strains of phosphorus bacteria has not identified, the other two respectively are Acinetobacter sp. and Escherichia sp.4. Cellulose-decomposing activity, antibacterial activity and phosphate solubilizing capacity198 strains of heterotrophic bacteria are inoculated CMC substrate, stained by congo red and rescreened by liquid medium. 4 strains are determined as highly active cellulose-decomposing bacteria.Antibacterial activity of 198 strains of heterotrophic bacteria on the jar fermentation are determined in term of the cup-plate method. The results show that 15 strains with activity towards Staphylococcus aureus;8 strains with activity towards Bacillus subtilis;11 strains with activity towards Escherichia coli. Phosphate solubilizing bacteria are screened by Ca3(PO4)2 culture medium. Activity of strains transferred to liquid culture medium are measured solubilizing rate and quantity of dissolved phosphorus after 9d .The results show that 2 strains of efficient decomposition of phosphorus are rescreened by liquid fermentation medium.The experimental results show that Huguangyan is a kind of poornutrient lake and water quality belongs to the earth,s surface waterⅡ.Bacteria composition of Huguangyan is dominated by Firmicutes, which is a major feature to distinguish it from other oligotrophic lakes; the proportion of Gram-positive bacteria is far higher than that of other domestic and foreign fresh water lake, which is another feature; strains with cellulolytic activity accounted for 24% of the total, strains with antibacterial activity accounted for 17%, solubilizing bacteria is more , but active is less strong.