邻苯二甲酸二（2-乙基）己酯降解菌的筛选鉴定及固定化研究

发布时间：2018-05-15 07:21

  本文选题：邻苯二甲酸二(2-乙基)己酯降解菌 + 生物降解　； 参考：《江苏科技大学》2015年硕士论文

【摘要】：从污水处理厂活性污泥和垃圾填埋场垃圾渗滤液中分离出3株以邻苯二甲酸二(2-乙基)己酯(DEHP)为唯一碳源生长的细菌菌株S1、S2、S3。通过形态观察、生理生化实验和16S rDNA序列分析等手段对菌株进行了鉴定。研究了这3株菌的生长特性和降解特性,优化了菌株降解DEHP的工艺条件,探讨了菌株降解底物的广谱性。制备了竹炭/聚氨酯复合材料,并对其进行了表征。将分离的菌株固定到竹炭/聚氨酯复合材料上,并研究了固定化菌对DEHP的降解特性。菌株的鉴定和生长特性研究结果表明:菌株S1为代尔夫特菌(Delftia sp.),其最适生长温度为30℃、pH范围为7-8,底物浓度为800mg/L;S2为睾丸酮丛毛单胞菌(Comamonas testosterone),其最适生长温度为30℃,pH范围为7-9,底物浓度为400-800mg/L;S3为金黄色杆菌属(Chryseobacterium sp.),其最适生长温度为30℃,pH为8,底物浓度为400mg/L。菌株对DEHP的降解工艺优化结果表明,菌株S1降解DEHP的适宜条件为:pH为8,温度30℃,投菌量为5%,底物浓度800mg/L;菌株S2降解DEHP的适宜条件为:pH为8,温度30℃,投菌量为5%,底物浓度400mg/L;菌株S3降解DEHP的适宜条件为:pH为7,温度30℃,投菌量为10%,底物浓度400mg/L。在最适条件下,菌株S1能在72h内将浓度为800mg/L的DEHP基本降解完,菌株S2能在72h内将浓度为400mg/L的DEHP基本降解完,菌株S3降解完400mg/L的DEHP需要120h。菌株降解底物的广谱性研究结果表明,三株菌均能有效降解DMP、DEP、DBP和DNOP,培养5d后菌株S1对DMP、DEP、DBP、DNOP的降解效率均在60%以上,菌株S2对DMP、DEP、DBP、DNOP的降解效率均在50%以上,菌株S3对DMP、DEP的降解效率达70%以上,对DBP和DNOP的降解率在40%左右。制备的竹炭/聚氨酯复合材料与聚氨酯相比,化学结构并未发生改变,含有大量亚氨基、氨基、羟基等活性化学基团,但化学稳定和孔隙率有了明显提高。3株菌在竹炭/聚氨酯复合载体上的固定化条件为:以竹炭含量为3%的竹炭/聚氨酯复合材料作为固定化载体,固定化载体用量为0.025g,最佳固定化时间是24h。在此固定化条件下,载体对菌株S1、S2、S3的最大吸菌量分别为216mg/g、204mg/g和212mg/g。菌株S1,S2,S3经竹炭/聚氨酯复合材料固定后,适应期明显缩短,对DEHP的降解速度和降解效率显著提高。竹炭/聚氨酯复合材料是一种固定菌株S1、S2、S3的理想载体。
[Abstract]:Three strains of bacterial strain S1S2OS3 were isolated from activated sludge and landfill leachate of sewage treatment plant, with dioxy 2-ethyl hexyl phthalate (DEHP) as the sole carbon source. The strains were identified by morphological observation, physiological and biochemical experiments and 16s rDNA sequence analysis. The growth and degradation characteristics of the three strains were studied, the process conditions of DEHP degradation were optimized, and the broad-spectrum properties of substrate degradation were discussed. Bamboo charcoal / polyurethane composites were prepared and characterized. The isolated strains were immobilized on bamboo charcoal / polyurethane composites and the degradation characteristics of DEHP by immobilized bacteria were studied. The results of identification and growth characteristics showed that strain S1 was Delftia sp., the optimum growth temperature was 30 鈩，

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