西维因降解菌株A-1的分离及其西维因降解途径的研究
时间:2018-08-02 16:03 来源:毕业论文 作者:毕业论文 点击:次
| 摘要：西文因是一种应用广泛的氨基甲酸酯类杀虫剂，由于该类农药大面积、持续地使用，其在环境中的残留会对人类的健康和生态环境的平衡产生潜在的威胁。以生物降解方式处理环境中残留的西文因污染是一种环境友好型的处理方式，具有彻底性、高效性和不会产生二次污染等优势。26605 本研究从受西文因污染的土壤中分离得到一株西文因降解菌A-1，根据其生理生化特性16s rRNA序列相似性比较，初步鉴定其为Pseudomonas sp. 。 菌株A-1的最适生长pH为7.0，最适生长温度为30℃，最适装液量为25mL，最适生长NaCl浓度为5 g•L-1。降解西文因的最适温度为30℃，与菌体的最适生长温度相一致；通气量对菌株A-1降解西文因的影响较大，通气量越大，降解速率越快；降解速度与接种量成正相关，接种量越大，西文因降解速度越快。 通过对菌株A-1降解西文因中间产物的HPLC-MS分析推断，和对可能中间产物进行降解实验得出，A-1具有与C5pp相同的降解西文因的途径。 毕业论文关键词：西文因；分离鉴定；降解途径 Isolation of Carbaryl Degradation Strain A-1 and Study on the Degradation Pathway of Carbaryl Abstract: Carbaryl is a widely used carbamate insecticide. Its residual in the environment will have a potential threat to human health and ecological environment because of the large area of these pesticides, continuous use. The biodegradation of residual carbaryl contamination in the environment is an environmentally friendly treatment that is thorough, efficient and does not produce secondary pollution. A carbaryl-degrading bacterium A-1 was isolated from the contaminated soil in this study. It was initially identified as Pseudomonas sp. according to their physiological and biochemical characteristics, degradation characteristics and 16s rRNA similarity comparison. The optimum growth pH of the strain A-1 was 7.0. The optimum growth temperature was 30℃. The optimum loading volume was 25mL, the optimum NaCl concentration was 5 g•L-1. The optimum temperature for degradation of carbaryl was 30℃, which was consistent with the optimum growth temperature of the cells. The effect of ventilation on the degradation of carbaryl by strain A-1 was greater. The higher the ventilation, the faster the degradation rate was. The rate of degradation was positively correlated with the inoculation amount. The greater the inoculation amount, the faster the degradation rate of carbaryl. In the deduced by HPLC-MS analysis of the degradation of the carbaryl intermediates of strain A-1 and degradation of the possible intermediates, it was found that A-1 had the same pathway for degradation of carbaryl as C5pp. Key words: carbaryl; isolation and identification; degradation pathway 目 录 摘要3 关键词3 Abstract3 Key words3 引言4 第一章 西文因降解菌的分离和生物学特性及降解特性研究 5 1 材料与方法 5 1.1 培养基与菌株 5 1.2 化学试剂 5 1.3 西文因降解菌的分离 5 1.4 西文因降解菌的鉴定 6 1.4.1 菌体总DNA的提取 6 1.4.2 降解菌株16S rRNA的PCR扩增 6 1.4.3 PCR产物的T/A克隆，酶连产物的转化 6 1.4.4 菌株质粒DNA的小量提取 6 1.4.5 16S rRNA基因序列的测定 7 1.4.6 降解菌株的系统发育分析 7 1.5 菌体生长量的测定 7 2 结果与分析 7 2.1 西文因降解菌的分离 7 2.2 菌株的降解特性 8 2.3 菌株生长及降解特性的影响因素 9 3 小结 12 第二章 西文因降解途径的分析 13 1 材料与方法 13 1.1 培养基与菌株 13 1.2 化学试剂 13 1.3 分析方法 13 1.4 代谢途径的推断 13 2 结果与分析 13 2.1 中间产物的HPLC-MS分析 13 (责任编辑：qin) |