3-溴咔唑降解菌的篩
發(fā)布時(shí)間：2019-03-09 19:17
【摘要】：鹵代咔唑?qū)儆陔s環(huán)芳烴類化合物,其結(jié)構(gòu)與多氯二苯并呋喃相似,也具有類二VA英毒性、生物累積性和持久性等性質(zhì)。作為一種新型持久性有機(jī)污染物,自20世紀(jì)80年代在環(huán)境中首次發(fā)現(xiàn)至今,已有20多種鹵代咔唑在土壤和河流湖泊沉積物中被檢出。但是目前關(guān)于鹵代咔唑環(huán)境行為的研究少之又少,相關(guān)數(shù)據(jù)也非常缺乏,所以相關(guān)研究的開(kāi)展具有很好的理論和實(shí)際意義。本論文以3-溴咔唑?yàn)閷?duì)象,對(duì)其微生物降解過(guò)程進(jìn)行了研究。在蘇州某農(nóng)藥廠的污染土壤中篩選分離得到三株具3-溴咔唑降解活性的菌株,命名為CH-1,CH-2和CH-3,選取具較高活性的菌株CH-1開(kāi)展進(jìn)一步研究,通過(guò)16S r DNA基因序列同源性分析及生理生化特性研究,確定其為寡養(yǎng)單胞菌屬(Stenotrophomonas sp.)。進(jìn)一步確定最適降解條件,單因素實(shí)驗(yàn)結(jié)果表明菌株CH-1降解3-溴咔唑的最適條件為:p H 7.0,溫度30℃。在此條件下,8 d后初始濃度為50 mg/L的3-溴咔唑降解率達(dá)到70%左右;當(dāng)p H值小于5.0或大于9.0時(shí),菌株的降解活性顯著受到抑制;當(dāng)溫度在30~35℃之間時(shí),菌株有較好的降解效果,當(dāng)溫度低于20℃或高于40℃時(shí),菌株的降解效率明顯降低;當(dāng)初始濃度為25~50 mg/L時(shí),CH-1有很好的降解效果,當(dāng)初始濃度高于100 mg/L時(shí)抑制作用明顯,初始濃度為200mg/L時(shí)8 d降解率下降為41%;外加碳源酵母粉和葡萄糖對(duì)降解效率也有一定的促進(jìn)作用。最后通過(guò)產(chǎn)物分析初步推斷降解途徑。利用氣相色譜-質(zhì)譜聯(lián)用儀(GC-MS)對(duì)菌株CH-1降解3-溴咔唑的降解產(chǎn)物進(jìn)行檢測(cè)和鑒定,確定其主要降解產(chǎn)物為(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，
本文編號(hào)：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，
本文編號(hào)：2437775
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