Study On The Influence Of Applied Arsenic On Microbial Population And Ecology In Soil

There is a great deal of research about arsenic contaminated soil in the world, but research about applied arsenic soil is a fat lot. This study mostly employed indoor simulation means, adding 4 different As concentrations ranging from 0 to 2000mg/kg in soils, working over the effects on soil microorganisms, the biological effects of soil microorganisms, and comparing with investigated soil. While arsenic-resisted strain can be filtrated from tame soil, it can provide theoretical basis for the bioremediation technology.Microbial population in the applied arsenic tame soil reduced along with the mass of arsenic adding. The amount of autotrophic microorganisms reduced along with the concentration of arsenic adding, it indicated that arsenic in the soil could restrain and poison the autotrophic microorganisms, and then the amount of autotrophic microorganisms rising up along with the concentration of arsenic; the amount of heterotrophic microorganisms varied like wave, it indicated that low concentration of arsenic could stimulate the growing of heterotrophic microorganisms and high concentration of arsenic could restrain the heterotrophic microorganisms.The investigation of arsenic contaminated soil indicated that, in the organic culture medium with no arsenic, the microbial population of tea plantation soil is more than that in arsenic contaminated soil. In the culture medium with arsenic, the microbial population in arsenic contaminated soil is more than tea plantation. Especially in the culture medium with high concentration of arsenic, the microbial population of tea plantation decreased obviously but the microbial population in the arsenic contaminated soil was rising up obviously, that's because there were large numbers of arsenic-resisted microorganisms in the arsenic contaminated soil and arsenic became the necessary element of some arsenic-resisted microorganisms in their growing.The article studied the effect of soil microbial biology from different concentration of applied arsenic by molecular biology experimental methods. The result of the experiment indicated: almost microorganisms in the soil could resist arsenic, and individual population is sensitive to arsenic-contamination so that the population came down obviously. Along with the concentration of arsenic adding, the effect for diversity of soil microbial gene enhanced, some bands became dark or disappeared, indicating that arsenic-contaminated had obvious toxic action to microbial population in the soil. When the arsenic concentration rose to 2000mg/kg, some bands became bright, and some new bands appeared, indicating that new arsenic-resisted flora appeared. Preponderant flora existed in each treated soil pervasively, but the variety of bands' brightness in different track was obvious, indicating that the population of microorganisms in the soil was rising up along with the intensity of arsenic-contaminated.Screening from tame soil with high concentration arsenic applied, strain B,C,F,N,P belonged to Arthrobacter sp., and E,K belonged to Comamonadaceae bacterium, and I,L belonged to Alcaligenes sp., and J belonged to Micrococcineae bacterium.In summary, applied arsenic had obvious effect to the population and biology of microorganisms in the soil. The filtration of the arsenic-resisted strain had actual meaning to using microorganisms to remedy arsenic-contaminated soil.