施氏假单胞菌PFS-4的筛

发布时间：2018-08-25 20:24

【摘要】：从长期施用二氯喹啉酸的土壤中分离到1株能以二氯喹啉酸为碳源生长的菌株,命名为PFS-4。经16S rRNA基因序列和生理生化特性分析,将菌株PFS-4鉴定为施氏假单胞菌(Pseudomonas stutzeri)。以麦秆吸附-海藻酸钠包埋方式对菌株进行复合固定,采用正交实验对固定条件进行优化,研究温度、pH值、碳源对固定化菌剂降解二氯喹啉酸的影响;考察固定化菌剂对污水中二氯喹啉酸的去除效果,并对比分析游离菌及固定化菌剂去除能力的差异。结果表明,固定化菌剂制备的最佳条件为:海藻酸钠质量分数为5%,Ca Cl2为4%,菌胶比1∶2,交联时间5 h。在温度为30℃、pH值为7的条件下,经5 d培养,固定化菌剂对500 mg·L~(-1)二氯喹啉酸降解率为92.3%。在处理污水中二氯喹啉酸时,游离菌的降解能力受到极显著抑制(P0.01),而对固定化菌剂降解率影响相对较小,去除率保持在64%以上。麦秆吸附-海藻酸钠包埋固定化菌剂对不良环境具有较好缓冲性,可用于微生物降解菌的开发利用。
[Abstract]:A strain, named PFS-4., which can grow with dichloroquinolinic acid as carbon source, was isolated from the soil treated with dichloroquinolinic acid for a long time. The 16s rRNA gene sequence and physiological and biochemical characteristics were analyzed, and the strain PFS-4 was identified as (Pseudomonas stutzeri). The strain was immobilized by wheat stalk adsorption-sodium alginate. The optimum conditions were optimized by orthogonal experiment. The effects of temperature pH value and carbon source on the degradation of dichloroquinolinic acid by immobilized bacteria were studied. The effect of immobilized bacteria on the removal of dichloroquinolinic acid from sewage was investigated, and the difference between free bacteria and immobilized bacteria was analyzed. The results showed that the optimum conditions for preparation of immobilized bacteria were as follows: sodium alginate was 5% Ca Cl2, the ratio of bacteria to gum was 1: 2, and the crosslinking time was 5 h. The degradation rate of 500 mg L ~ (-1) dichloroquinolinic acid was 92.3 when the temperature was 30 鈩，

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