3-溴咔唑降解菌的筛
发布时间：2019-03-09 19:17
【摘要】：卤代咔唑属于杂环芳烃类化合物,其结构与多氯二苯并呋喃相似,也具有类二VA英毒性、生物累积性和持久性等性质。作为一种新型持久性有机污染物,自20世纪80年代在环境中首次发现至今,已有20多种卤代咔唑在土壤和河流湖泊沉积物中被检出。但是目前关于卤代咔唑环境行为的研究少之又少,相关数据也非常缺乏,所以相关研究的开展具有很好的理论和实际意义。本论文以3-溴咔唑为对象,对其微生物降解过程进行了研究。在苏州某农药厂的污染土壤中筛选分离得到三株具3-溴咔唑降解活性的菌株,命名为CH-1,CH-2和CH-3,选取具较高活性的菌株CH-1开展进一步研究,通过16S r DNA基因序列同源性分析及生理生化特性研究,确定其为寡养单胞菌属(Stenotrophomonas sp.)。进一步确定最适降解条件,单因素实验结果表明菌株CH-1降解3-溴咔唑的最适条件为:p H 7.0,温度30℃。在此条件下,8 d后初始浓度为50 mg/L的3-溴咔唑降解率达到70%左右;当p H值小于5.0或大于9.0时,菌株的降解活性显著受到抑制;当温度在30~35℃之间时,菌株有较好的降解效果,当温度低于20℃或高于40℃时,菌株的降解效率明显降低;当初始浓度为25~50 mg/L时,CH-1有很好的降解效果,当初始浓度高于100 mg/L时抑制作用明显,初始浓度为200mg/L时8 d降解率下降为41%;外加碳源酵母粉和葡萄糖对降解效率也有一定的促进作用。最后通过产物分析初步推断降解途径。利用气相色谱-质谱联用仪(GC-MS)对菌株CH-1降解3-溴咔唑的降解产物进行检测和鉴定,确定其主要降解产物为(2E,4Z)-6-(2氨基-5溴苯基)-2氧基-2,4-二烯酸。
[Abstract]:Halocarbazole belongs to heterocyclic aromatic compounds. Its structure is similar to that of polychlorinated dibenzofuran (PCDF). It also has the properties of toxicity bioaccumulation and persistence of diVA-like compounds. As a new persistent organic pollutant, more than 20 halogenated carbazoles have been detected in soil, river and lake sediments since they were first discovered in the environment in the 1980s. However, there are few studies on the environmental behavior of halocarbazole and lack of relevant data, so it is of great theoretical and practical significance to carry out the related research. In this paper, the microbial degradation process of 3-bromocarbazole was studied. Three strains with 3-bromocarbazole degrading activity were isolated from the contaminated soil of a pesticide factory in Suzhou, and named CH-1,CH-2 and CH-3, to select high active strains CH-1 for further study. By homology analysis of 16s r DNA gene sequence and physiological and biochemical characteristics, the 16s r (Stenotrophomonas sp.). Gene was identified as Oligomonas spp. (Stenotrophomonas sp.). The results of single factor experiment showed that the optimum degradation conditions of 3-bromocarbazole by strain CH-1 were: p H 7.0 and temperature 30 鈩，
本文编号：2437775
[Abstract]:Halocarbazole belongs to heterocyclic aromatic compounds. Its structure is similar to that of polychlorinated dibenzofuran (PCDF). It also has the properties of toxicity bioaccumulation and persistence of diVA-like compounds. As a new persistent organic pollutant, more than 20 halogenated carbazoles have been detected in soil, river and lake sediments since they were first discovered in the environment in the 1980s. However, there are few studies on the environmental behavior of halocarbazole and lack of relevant data, so it is of great theoretical and practical significance to carry out the related research. In this paper, the microbial degradation process of 3-bromocarbazole was studied. Three strains with 3-bromocarbazole degrading activity were isolated from the contaminated soil of a pesticide factory in Suzhou, and named CH-1,CH-2 and CH-3, to select high active strains CH-1 for further study. By homology analysis of 16s r DNA gene sequence and physiological and biochemical characteristics, the 16s r (Stenotrophomonas sp.). Gene was identified as Oligomonas spp. (Stenotrophomonas sp.). The results of single factor experiment showed that the optimum degradation conditions of 3-bromocarbazole by strain CH-1 were: p H 7.0 and temperature 30 鈩，
本文编号：2437775
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