Isolation And Identification Of A Dmso Degrading Bacteria And Its Degradation Characteristics

A bacterial strain, capable of utilizing DMSO as sole carbon source was isolated from activated sludge collected from wastewater-treating system of a pesticide manufacturer. This strain was identified as Pseudomonas alcaliphila according to its morphological, physiological and biochemical analysis and the analysis of its16S rRNA gene sequence, and named DO-2.DO-2could utilize glucose better of carbon source, and it could utilize peptone better of nitrogen source. The optimal C/N (mol) for it is5:1. The strain grew best after28h in LB medium;The optimal growth temperature and pH is35℃and9.0respectively.Ventilation had great impact on the growth of DO-2, adequate oxygen could improving the growth of the strain. Strain could grow well in the NaCl solution with the concentration of10-20g·L-1, improving the concentration of NaCl,the strain would grow bad.DO-2has resistance to a few antibiotics, and has sensitivity to rarely sorts, such as Gentamicin.DO-2strains using DMSO as the sole carbon source48h, the growth reached the maximum and stabilized at this time also the best on the degradation of DMSO, the concentration of DMSO was just11.72mg·L-1.The strain degraded benazolin-ethyl the best at35℃and pH9.0. Low concentrations of DMSO degraded rapidly,when the concentration of DMSO increasing to400mg·L-1,producing toxic effects on the strain,inhibited the degradation of DMSO. Improving inoculation rate from0.5%to4%could speed up the degradation of DMSO;Ventilation great effect on the degradation of DMSO.Used sodium alginate embedding the DMSO degrading strain DO-2,results showed that mechanical strength of immobilized beads best and the degradation of DMSO effect was best when the concentration of sodium alginate was2%, the concentration of CaCl2was3%and immobilized time was6h.Add degrading strains favor the degradation of DMSO wastewater and improve the wastewater COD removal, COD removal could reach92%and93%; In continuous operation conditions, the loss of suspended bacteria easily lead to decline in COD removal, while the immobilized bacteria are easily preserved, COD removal remain reached83.15%. Immobilization is conducive to resolving the loss of the actual wastewater treatment sludge problems, and has good application prospects.