Characterization Of A Chlorothalonil-Degrading Bacterium And The Effect On Remediation Of Polluted Soil

The chlorothalonil have long-term applied to the soil, causing serious pollution of soil. This experiment mainly study the microorganism of the technology of chlorothalonil degradation. This test is through long-term of chlorothalonil from on the soil of the36strains get screening of chlorothalonil degradation bacterium, From the three strains of chlorothalonil were high efficiency degradation bacterium, these three degrading bacteria degradation of the characteristic, In addition, Also carry a soil degradation test, the reason of the strains are presented here:1. By adding a rich culture method and enrichment, training, From the surveyed got36samples of plant resistance strains, We found that after screening get more kinds of degrading bacteria for bacteria. Strains B2, B31, B36of chlorothalonil as the only carbon source of inorganic salt culture medium to grow on. By high gas chromatography spectrometer the strains of the determination of degradation ability, and the results show that:The inorganic salts liquid medium,30℃,180r/min constant temperature wave bed oscillation training12days later, Degradation rate were80.44%、83.74%、82.74%.2. Through the form observation, bacterium of dyeing and physical and chemical properties analysis,16SrDNA sequence analysis, confirmed B2, B31, B36strains of the reason respectively, Enterbacteriacea, Achromobacter, Klebsiella.3. In growth conditions, the results of the study show that:B2best condition is30℃temperature degradation, adding amount solution of50ml/250ml, optimal pH for7, degradation rate was80.44%, the optimal carbon source is the sucrose, the optimum nitrogen source for beef cream, optimal carbon nitrogen than is3/1, the optimum conditions drop solution rate was91.45%.B31the best conditions for the temperature25℃degradation, adding amount of50ml solution/250ml, optimal pH for7, degradation rate is83.74%, and the optimal carbon source is the sucrose, the optimum nitrogen source for yeast juice, optimal carbon nitrogen than is2/1, the optimum condition of the degradation rate of91.24%.B36best degradation conditions for30℃temperature, adding amount of50ml solution/250ml, optimal pH for7, degradation rate was82.74%, the optimal carbon source is the sucrose, the optimum nitrogen source for beef cream, optimal carbon nitrogen than is3/1, the optimum condition of the degradation rate of88.62%.4. Highly effective gas chromatography (HPLC) to the strains of the bacteria the degradation of soil suppress the clear effect. Results show that the technology used in the system of soil add of chlorothalonil80%-in the recovery120%to pesticide residue extraction standard requirements. Will strains in with20mg/10g of chlorothalonil sterilization soil, the results showed, B2, B31, B36three kinds of bacteria single additive to soil degradation efficiency after less than in the laboratory is generally in triangle bottles of test data, the degradation rate at50%range float. Two strains of degradation efficiency is a single hybrid strains of the numerical value of dosing a little high, are less than80%, the reason of this kind of phenomenon is likely to be common existence conditions, form symbiotic model, so that each of the strains of chlorothalonil use for better. Three kinds of bacteria in the case of mixed, degradation efficiency is the highest, to80.68%, the effect is good.The study of chlorothalonil residues of soil and environmental bioremediation is of great significance.