二甲戊灵降解细菌的筛选、鉴定及其降解特性研究

采用富集培养法,从新疆棉田土壤中分离筛选二甲戊灵高效降解菌株,研究不同培养条件对二甲戊灵降解的影响,以期为二甲戊灵污染土壤的治理提供依据。结果表明,经平板法初筛获得9株高度耐受二甲戊灵的降解细菌,其中,菌株JY-2和JY-5在3 d后对100 mg/L二甲戊灵的降解率在75%以上。此2株细菌经形态观察和16S rDNA序列分析,被初步鉴定为沙雷氏菌(Serratia sp.)和假单胞菌(Pseudomonas sp.)。2株细菌均能在以二甲戊灵为唯一碳源的无机盐培养基中生长,其在外加碳源量0.5%、菌株接种量10%、初始二甲戊灵质量浓度200 mg/L、pH值7.0、温度30℃的最佳培养条件下振荡培养3 d,对二甲戊灵的降解率分别可达83.34%和82.79%。可见,此2株细菌有较强的适应能力,能高效、快速地降解二甲戊灵。

Screening,Identification and Degradation Characterization of Pendimethalin Degrading Bacteria

To provide the basis for the treatment of soil contaminated by pendimethalin,the efficient strains degrading pendimethalin were screened out by enrichment culture method from Xinjiang cotton field soil and the effects of different culture conditions were studied.The results showed that nine strains highly tolerant to pendimethalin were obtained from the soil by flat plate method,in which two strains (JY2 and JY-5) in culture fluid could degrade more than 75％ of 100 mg/L pendimethalin after 3 days.By morphological observation and 16S rDNA sequence analysis,the two bacterial strains were identified as Serratia sp.and Pseudomonas sp.,respectively.In addition,the strains could utilize pendimethalin as sole carbon source for growth,and under the optimum culture conditions of 0.5％ carbon source,10％ inoculum,200 mg/L pendimethalin,pH 7.0 and temperature 30 ℃,the pendimethalin degradation rates of the two strains could respectively reach 83.34％ and 82.79％.Obviously,these two strains had a strong ability to adapt the environment,and the degradation for pendimethalin was highly efficient and rapid.