《高效脱色菌的筛选及对偶氮染料降解的研究》由会员分享，可在线阅读，更多相关《高效脱色菌的筛选及对偶氮染料降解的研究（92页珍藏版）》请在金锄头文库上搜索。
1、石河子大学 硕士学位论文 高效脱色菌的筛选及对偶氮染料降解的研究 姓名：张胜琴 申请学位级别：硕士 专业：生物化工 指导教师：李春;曹竹安 20100501 石河子大学硕士学位论文 摘 要 - I - 摘摘 要要 偶氮染料占有机染料总产量的 80%， 它们包含一个或多个偶氮键， 由于其色谱齐全， 被广泛地应用于印染、印刷及其他多种工业领域。但是，约有 2%的染料在生产过程中 被排出。由于这些染料本身或其代谢产物有毒性或致癌性，染料废水已经造成严重的环 境问题。 很多物理-化学方法已经被广泛应用于染料废水的处理，但是，这些方法往往价格 高昂，且容易产生二次污染，所以应用受到限制。用微生物法降解染
2、料废水，成本低而 且环境友好，已引起越来越多研究者的重视。近几年，人们发现了许多高效降解偶氮染 料的微生物，包括细菌，真菌及藻类。 本论文以含偶氮染料酸性大红 GR 的印染废水为研究对象，分离到在好氧条件下和 厌氧条件下有较高脱色能力的菌株共 38 株，经进一步筛选得到 3 株高效脱色菌株，分 别命名为 ZL3-1、Z1 和 Z2，其中 Z1 和 Z2 能在高碱条件下对染料脱色。经 16/26SrDNA 分析，鉴定菌株分别为 ZL3-1 热带假丝酵母（Candida tropicalis） ，Z1 巴斯德葡萄球菌 （Staphylococcus pasteuri） ，Z2 为蜡状芽孢杆菌（Ba
3、cillus cereus） 。 研究表明， 这些菌株均不能以染料为唯一碳源， 最佳碳源为葡萄糖， 加入量为 5g/L。 无机氮源对菌体的生长和脱色影响不大。菌株 ZL3-1 适宜在有氧条件下脱色，为温度不 敏感菌株，在 25-40之间脱色影响不大，最佳脱色温度 30。菌株 ZL3-1 对环境中 的 pH 值和染料浓度有较大的适应和耐受能力，在 pH3-9 和 50mg/L-300mg/L 的浓度下 都能保持较高的脱色降解活性。原始的 ZL3-1 菌株对盐度的耐受力很差，经驯化后可耐 盐 15%。菌株 Z1 和 Z2 为耐碱菌株，在厌氧条件，pH12 条件下的脱色率仍高于 90%。 且对染料浓
4、度有很高的耐受力， 在 300mg/L 时 40h 脱色率为 93%。 这三株菌均可对多种 染料脱色， 具有脱色的广谱性， 并且具有耐盐耐碱性， 有望应用于实际染料废水的处理。 通过紫外-可见光谱、HPLC 和 GC/MS 等技术分析可知，酸性大红 GR 脱色机理主 要是偶氮双键在催化作用下进行的还原裂解反应， 同时在脱色过程中伴随产生了中间产 物芳香胺类化合物。研究还对 ZL3-1 和 Z1 的脱色作用酶进行了研究，发现 ZL3-1 有 3 种作用酶，分别为偶氮还原酶、漆酶和木质素过氧化物酶；Z1 的脱色作用酶为偶氮还 原酶。 基因工程菌的构建主要从已知偶氮还原酶基因和未知偶氮还原酶基因两方
5、面构建， 已知偶氮还原酶是以克雷伯氏菌为模板，未知偶氮偶氮还原酶基因是以 ZL3-1 为模板， 构建出有脱色能力的菌株。 关键词关键词: 偶氮染料 酸性大红 GR 脱色 生物降解 基因工程菌 石河子大学硕士学位论文 Abstract - II - Abstract Azo dyes, characterized by the presence of at least one azo bond (-N=N-) bearing aromatic rings, represent 80% of the total colorants listed in the color index and are
6、 extensively used in textile dyeing, paper printing and many other industries. However, it is estimated that 2% of these dyes are discharged in aqueous effluents during the manufacturing process. Waste containing dye has raised an important environmental problem since some of the dyes or their metab
7、olites may be highly toxic and carcinogenic,. Although many physical-chemical methods have been conducted in the process of waste from textile manufacturing plants, they are generally expensive and prone to lead to secondary pollution. Therefore, their application is limited. Since the microbial bio
8、degradation of dyes is low-cost and environmental-friendly, it has raised more attention by researchers as a better alternative. In recent years, many microorganisms have been developed for high-effect degradation of azo, including bacteria, fungi and algae. We used dyeing wastewater containing Acid
9、 Scarlet GR as the subject in the study, which is belong to azo dyes. 38 high-efficient decoloring strains were separated under aerobic condition and anaerobic condition. After further screening，3 strains with the optimal decoloring were screened and named ZL3-1, Z1 and Z2. Z1 and Z2 showed best eff
10、ect on decoloring at high alkalescence. Through sequencing analysis of 16/26s rDNA gene, these strains were identified as Candida tropicalis ZL3-1, Staphylococcus pasteuri Z1 and Bacillus cereus Z2. The result showed that these strains were unable to used dyes as the sole carbon source, the optimal
11、carbon source was glucose, the concentration of glucose was 5g/L. Inorganic nitrogen sources had little effect on the cell growth and decolorization. The strain ZL3-1 was suitable for growth and decolorization under aerobic conditions, as it was temperature-unsensitive strain. Temperature between 25
12、-40, has not effect on the decolorization rate. Strain ZL3-1 had a adaptive and resistive capability of pH and dye concentration in environment. It could kept the higher activity of decolorization and degradation under pH 3.0-9.0 and the dye concentration at 50-300mg/L. Original strain ZL3-1 had poo
13、r tolerance to salinity, but after acclimation the resistive of salinity became 15%. Z1 and Z2 were alkali-resistant bacteria, under anaerobic condition, after 40h the decolorization rate were above 90% at pH 12. It also can kept the higher activeness of decolorization and 石河子大学硕士学位论文 Abstract - III
14、 - degradation under the high dye concentration, the decolorization rate was 93% at 300mg/L after 40h. All the three strains can decolorized various dyes inclued acid dyes, basic dyes, direct dyesand so on. they had broad-spectrum of decolorization and may be used in the actual dye wastewater. Accor
15、ding to the analysis of UV-Vis absorption spectrum, HPLC and GC-MS spectrum, the decolorization mechanism of Acid Scarlet GR was that cracking reaction, which produced aromatic amine as an intermediate product happened on the azo-bond of dyes. Construction of genetically engineered bacteria mainly b
16、egan from two aspects: one was known the azo reductase gene and the other was unknown azo reductase gene. The former took klebsiella pneumoniae as templat and the latter took Candida tropicalis ZL3-1 as template. The results of construction also had breakthrough, but not ideal. Key words: azo dye Acid Scarlet GR decolorization bio-degradation genetic enginee
