邻苯二甲酸二正戊酯高效降解菌的筛
发布时间：2018-09-17 12:11
【摘要】：邻苯二甲酸二正戊酯属于邻苯二甲酸酯类的一种,该类物质是一种在全世界范围内广泛使用的增塑剂,并且有环境激素作用,由于其在生态环境中的广泛存在,对动物和人体有潜在危害。目前并没有关于邻苯二甲酸二戊酯的降解报道。本论文采用污水处理厂处理池中的活性污泥,经过污泥曝气驯化、富集、分离筛选得到一株能以邻苯二甲酸正二戊酯为唯一碳源生长的菌株,命名为LS1。根据表型特征、生理生化特性,结合16SrRNA基因序列同源性比较,将LS1菌株初步鉴定为睾丸酮丛毛单胞菌(Comamonas testosteroni.)。通过研究其生长特性发现,菌株LS1在LB液体培养基中生长良好,8h时进入对数生长期,30～40h为稳定生长期;菌株LS1的最适生长温度为30℃,最适pH范围为7.0～8.0;装液量越少,菌株生长越好,装液量代表培养基中溶氧量,增加溶解氧的量有利于菌体生长;菌株对果糖、木糖、蔗糖、麦芽糖、葡萄糖等有机碳源的利用情况均较差;氮源中利用蛋白胨生长最好,其次是氯化铵和硝酸钾,基本不利用尿素和亚硝酸钠。菌株LS1具有较好的耐盐性,NaCl浓度在0～15 g/l范围内均能较优地生长,在废水处理应用中具有突出优势。菌株对邻苯二甲酸二正戊酯的降解特性表明,在30℃,pH=7.0条件下,菌株在培养基中培养48h即可降解200 mg/L的邻苯二甲酸正二戊酯;培养液中的菌株光密度随着邻苯二甲酸正二戊酯的降解相应的逐渐上升,并且伴随着pH的变化,表明菌株LS1以邻苯二甲酸正二戊酯为唯一碳源进行生长。菌株LS1在30℃、pH7.0～8.0条件下降解效果最好,与其生长的最适温度和pH一致。邻苯二甲酸正二戊酯的起始浓度越低,越容易被菌株利用,降解较快,;LS1还能够利用邻苯二甲酸为唯一碳源生长,不能利用其他邻苯二甲酸酯类。研究了菌株LS1降解DAP的降解动力学,得出了降解动力学方程。根据在NCBI库中找到的一段睾丸酮丛毛单胞菌CNB-2全序列中4,5-邻苯二甲酸双加氧酶基因片段设计引物,利用PCR技术在菌株LS1中成功扩增出了 4,5-邻苯二甲酸双加氧酶基因的片段;通过液质联用检测对邻苯二甲酸正二戊酯降解过程中的代谢产物,结合相关文献,推测代谢途径为:先水解为邻苯二甲酸,再双加氧生成顺式-4,5-二羟基-4,5-二氢邻苯二甲酸,然后脱氢生成4,5-二羟基邻苯二甲酸,后者再通过脱羧生成原儿茶酚,之后进入三羧酸循环,最终生成C0_2和H_20。
[Abstract]:Di-amyl phthalate is a kind of phthalate ester, which is a kind of plasticizer widely used in the world, and has the function of environmental hormone, because of its widespread existence in ecological environment. Potentially harmful to animals and human beings. There are no reports of the degradation of diamyl phthalate. In this paper, the activated sludge from the sewage treatment plant was treated with activated sludge. After the sludge was acclimated and enriched by aeration, a strain which could grow with n-diamyl phthalate as the sole carbon source was isolated and screened, named LS1.. According to phenotypic characteristics, physiological and biochemical characteristics and homology comparison of 16SrRNA gene sequence, LS1 strain was identified as (Comamonas testosteroni.). By studying its growth characteristics, it was found that the stable growth period of strain LS1 was 30 ~ 40 h after entering logarithmic growth phase in LB liquid medium for 8 h, the optimum growth temperature of LS1 was 30 鈩，
本文编号：2245883
[Abstract]:Di-amyl phthalate is a kind of phthalate ester, which is a kind of plasticizer widely used in the world, and has the function of environmental hormone, because of its widespread existence in ecological environment. Potentially harmful to animals and human beings. There are no reports of the degradation of diamyl phthalate. In this paper, the activated sludge from the sewage treatment plant was treated with activated sludge. After the sludge was acclimated and enriched by aeration, a strain which could grow with n-diamyl phthalate as the sole carbon source was isolated and screened, named LS1.. According to phenotypic characteristics, physiological and biochemical characteristics and homology comparison of 16SrRNA gene sequence, LS1 strain was identified as (Comamonas testosteroni.). By studying its growth characteristics, it was found that the stable growth period of strain LS1 was 30 ~ 40 h after entering logarithmic growth phase in LB liquid medium for 8 h, the optimum growth temperature of LS1 was 30 鈩，
本文编号：2245883
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