Study On Bacteria Mixtures Of Nicosulfuron·Atrazine Isolation And Degradation Characteristics

To nicosulfuron and atrazine degradation bacteria as the main research object, the study of its degradation characteristics of the system. Main content is as follows:(1) Using liquid chromatography residue detection conditions, chromatographic column C18reverse phase column, mobile phase of acetonitrile, methanol:water:glacial acetic acid=60: spoken10μL, flow rate:1.0ml/min, detection wavelength:254nm, the column temperature:25℃, sample size:10μl.Nicosulfuron cycling standard curve for Y=20.16532142X-1.0857226, R2=0.9999, the retention time:5.722min; Atrazine standard curve for Y=8.60050892X+1.0644156, R2=0.9999, the retention time:11.606min, phase relations very good, good chromatographic peak separation target, peak symmetry.(2) Nicosulfuron samples added recovery was86.43%-86.43%, adding atrazine the sample recovery rate81.75%-85.09%, high performance liquid chromatography (HPLC) coefficient of variation between1.38%to2.22%, the sample pretreatment method of addition recovery rate and the precision of the HPLC are accord with the requirement of pesticide residue detection technology, argues that this method is stable, and easy to operate, reliable, satisfy the requirement of experiment.(3) This experiment through collected in three different soil, by using liquid enrichment method three agents (nicosulfuron, atrazine and nicosulfuron+atrazine) degradation bacteria screening, crossed separation strains, were41strains, including6isolates the degradation rate is more than15%, respectively is YU6, YU10, Y15, Y16, U4, U13. By adding the total metabolites, two efficient degradation bacteria, YU6, U4respectively, including YU6degradation bacteria in the degradation of nicosulfuron capacity from17.68%to75.56%; U4degrading bacteria in the degradation of atrazine capacity from14.69%to32.84%.(4) By strain YU6, U4degradation characteristics of the study can be concluded that the optimal degradation conditions YU6strains of30℃, pH=6.0, the initial content is1.6%, nicosulfuron initial concentration of100mg/L; U4strain is the optimal degradation conditions of30℃, pH=7.0, initial content of0.4%sucrose, atrazine initial concentration of150mg/L.By strain YU6, U4establishes a compound bacteria degradation characteristics of the study can be concluded that the optimal degradation conditions for compound bacterium of30℃, pH=7.0, Compound bacterium (YU6:U4) the optimal distribution ratio is2:1,after dispensing of initial concentration of300mg/L, the nicosulfuron degradation rate was87.73%, the atrazine degradation rate was35.61%.(5) Through the appraisal of16SrDNA, YU6strains and coli Citrobacter freundii. S3-12similarity, the highest can amount to94.1%. U4strains and coli Ochrobactrum anthropi. SOA10similarity, highest can amount to97.4%.