偶氮染料的微生物脱色研究进展

微生物法是染料废水治理的重要方法。本文综述了特异性酶作用下好氧细菌和真菌对偶氮染料的脱色以及厌氧条件下氧化还原介质作为电子穿梭体时偶氮染料的非特异性还原过程。指出厌氧偶氮还原是偶氮染料还原的主要形式, 电子供体不同脱色效率不同。对目前生物法去除偶氮染料存在的问题进行了分析, 提出了相应的对策措施。     

脱色细菌的分离和对偶氮染料的脱色研究

从印染废水中分离到8株对多种染料具有较好脱色效果的细菌,在所试验的10种染料中对其中大部分都有较好的脱色作用,尤其对三种酸性黑10B、酸性黑NG、直接湖蓝的脱色率最高;在各菌株最适条件下对这三种染料脱色率都能达到80%以上,其中有些菌株对直接湖蓝的脱色率达到100%。本实验研究了这8个菌株在不同的pH值、温度、需氧量条件下对这三种染料的脱色情况,并对有代表性的菌株脱色前后的化学需氧量(COD)值进行测定来判断染料的降解情况。     

基因工程微生物生态学研究进展

基因工程微生物(genctically enginccred microorganism,GEM)生态学的研究已成为微生物分子生态学的一项主要研究内容之一．随着分子标记和分子生物学检测手段的引入,传统的微生物生态学研究被注入了新的活力,在分子水平上探讨基因工程微生物与环境及环境中土著生物之间的关系已成为可能．基因工程微生物生态学是一门内容涉及分子生物学、微生物学、生态学等诸多学科的新型交叉边缘学科．本文提出加紧进行转基因生物生态学和转基因生物的风险评价的研究工作,建立适合中国国情的检测手段和评价标准,有助于我国基因工程微生物生态学的健康发展．     

氧气对混合菌群脱色降解偶氮染料效果的影响

【背景】偶氮染料及其中间产物具有一定的环境毒性,利用混合菌群降解偶氮染料是一种环境友好型方法,但降解过程中氧气的存在起到至关重要的作用,可以促进或抑制偶氮染料的微生物降解作用。【目的】探讨氧气对偶氮染料微生物脱色液的影响,分析氧气对混合菌群脱色降解偶氮染料效果的影响。【方法】利用混合菌群DDMY1在3种培养条件(好氧、厌氧、兼氧)下,对7种偶氮染料进行脱色降解,探讨偶氮染料脱色液对氧气的响应情况,利用紫外可见分光光度法(ultraviolet visible spectrophotometry,UV-vis)和傅里叶变换红外光谱法(Fourier transform infrared spectroscopy,FTIR)对脱色产物进行分析。【结果】在兼氧和厌氧条件下反应48 h后的染料脱色液,与氧气充分接触后,部分偶氮染料微生物脱色液发生较为明显的复色现象,如活性黑5、直接黑38;UV-vis分析结果表明,这种复色现象是由于脱色液与氧气接触之后产生新物质所致;FTIR分析结果表明,混合菌群对发生复色反应的偶氮染料仍然具有一定脱色降解效果,但是脱色尚不够完全。【结论】兼氧和厌氧条件下,氧气对部分偶氮染料微生物脱色液具有较为明显的影响,从而影响混合菌群对偶氮染料的整体脱色效果,这可为今后研究偶氮染料彻底生物降解提供理论基础。     

假单胞菌S—42对偶氮染料的脱色和降解代谢

Pseudomonas S-42 was capable of decolorizing azo dyes such as Diamira Brilliant Orange RR(DBO-RR), Direct Brown M (DBM), Eriochrome Brown R(EBR) and so on. The cell suspension, cell-free extract and purified enzyme of Pseud. S-42 could decolorize azo dyes under similar conditions: the optimum pH and temperature laid 7.0 and 37 degrees C respectively. The efficiencies of decolorizing of DBO-RR, DBM, EBR by intact cells stood more than 90%. When the cell concentration was 15 mg(wet)/ml and the reaction time was 5 hours, the decolorizing activity for above three azo dyes by intact cells were 1.75, 2.4, 0.95 micrograms dye/mg cell, respectively. Cell-free extract and purified enzyme could well express the decolorizing activity only under the anaerobic condition and added NADH. Purified enzyme belongs to azoreductase, its molecular weight is about 34,000-2000 daltons, and its Vmax and Km for DBO-RR are 13 mumol.mg protein-1.min-1 and 54 mumol/L. The results of the detection of the biodegrading products of DBO-RR by spectrophotometric and NaNO2 reactional methods showed that the biodegradation of azo dyes was initiated by the reduction cleavage of azo bonds. It was hypothesized that biodegrading metabolism pathway of DBO-RR by Pseudomonas S-42.     

耐盐偶氮染料脱色菌株GYW的筛选及特性

从某印染厂排水沟的底泥中分离筛选到1株对偶氮染料具有脱色能力的耐盐菌株GYW, 经16S rDNA序列分析, 鉴定为盐单胞菌属(Halomonas)中度耐盐菌。实验结果表明, 菌株GYW可以耐受10%以上的高盐度, 对酸性大红GR和其它偶氮染料具有广谱的脱色能力, 处于对数生长期的细胞脱色能力最强。对酸性大红GR的最佳脱色条件为：温度30°C, pH 7.5, LB培养基。氯离子对酸性大红GR脱色的抑制作用较强, 硫酸盐对脱色影响不大, 添加甜菜碱可提高染料的脱色速率, 最佳添加量为200 mg/L。     

细菌利用不同碳、氮源共代谢降解脱色偶氮染料研究进展

本文主要综述了细菌利用碳、氮源等不同共代谢基质降解脱色偶氮染料的研究进展。综合文献结果表明,在单一碳源、单一氮源、复合碳氮源等不同共代谢基质条件下,细菌降解脱色偶氮染料的效能存在较大差异。其影响因素主要包括碳源种类、氮源种类、浓度、碳氮源复合比例等,其中碳、氮源种类影响最为显著。针对偶氮染料,只有提供合适的碳、氮源共代谢基质,才能对细菌降解脱色的效果起到明显的促进作用。同时,在不同碳、氮源共代谢基质条件下,细菌菌群群落结构及优势功能菌种差异较大,而不同碳、氮源共代谢基质作为偶氮染料还原脱色的电子供体,产生的脱色效能也有显著不同。最后,对利用碳、氮源共代谢降解脱色偶氮染料的研究方向进行了展望,认为复合合适的碳、氮源在提高细菌菌群降解脱色效率方面具有较大潜力,另一方面,细菌混合菌群利用碳、氮源共代谢降解脱色偶氮染料的微观分子生态学机制,酶学作用机制,功能菌种与功能蛋白之间相互作用机制等还有待深入研究。     

微生物对三苯基甲烷类染料脱色的研究进展

三苯基甲烷染料广泛应用于纺织印染、医药、生物染色、造纸、皮革、食品及化妆品等领域, 常见的有作为抗菌剂的孔雀石绿和结晶紫等。由于其特殊的化学结构, 在环境中较稳定且难以降解脱色, 因此其生物脱色降解的研究可为印染废水处理和染料污染环境的生物修复提供理论依据。本文从细菌、放线菌、真菌及藻类等微生物对三苯基甲烷类染料降解脱色研究新进展做综述。通过分析不同微生物脱色三苯基甲烷类染料的中间产物来探讨其降解机理和降解途径, 同时论及功能酶的分离纯化、酶学特性及其编码基因的克隆表达新进展, 并分别从基础理论和应用两方面对微生物降解三苯基甲烷类染料未来的研究方向进行了展望。     

脱水污泥中脱色偶氮染料功能菌群的驯化分离

【目的】获得降解混合偶氮染料的高效降解菌,应用于印染行业偶氮染料废水的生物处理和资源化。【方法】以某污水处理厂的脱水污泥作为分离源,经偶氮染料废水驯化后,分离筛选出9株偶氮染料脱色株(命名为T-1-T-9),通过形态观察、生理特征及基于16S rRNA基因序列的分子生物学鉴定,初步认定分离株分属于芽孢杆菌属(Bacillus)、微小杆菌属(Exiguobacterium)、寡单胞菌属(Stenotrophomonas)和副球菌属(Paracoccus)。【结果】所得分离株纯培养均可不同程度地脱色单一偶氮染料和混合偶氮染料,其中T-8对甲基橙和金橙I的脱色速率最大,40 h的脱色率分别为85.9%和86.2%,T-8菌株干粉也可在无外源碳源的条件下完全脱色金橙I。分离株混合培养脱色混合偶氮染料的效率明显高于纯培养,可达90.1%。【结论】脱水污泥作为脱色偶氮染料功能菌群的新来源具有良好的应用价值。     

微生物染料脱色研究进展

近年来,利用微生物对各种染料及染料废水脱色的研究报道很多,包括细菌、真菌等,脱色机制包括吸附脱色和降解脱色。综述了国内外有关这两大类微生物脱色研究的最新进展,对各种脱色机制在实际染料废水处理中的应用现状和研究方向进行了讨论。     

耐碱的偶氮染料脱色菌筛选及其特性的研究

从浙江某污水处理厂的活性污泥中筛选出若干株在高pH条件下对偶氮染料酸性大红GR有脱色能力的菌株,经脱色验证得到一株具有高效脱色活性的菌株Z1,经鉴定为巴斯德葡萄球菌(Staphylococcus pasteuri),并对此菌株的脱色特性进行了初步研究。结果表明,在厌氧条件下,Z1在pH7~12,40h对50mg/L的酸性大红GR脱色率均可达90%以上。该菌株对染料有较强的耐受力,在酸性大红GR浓度为300mg/L时,48h的脱色率仍可达93%。此外,该菌株能够对多种偶氮染料脱色,具有较好的脱色广谱性,有望应用于处理工业废水中的偶氮染料。     

Kinetic Studies of Reactive Azo Dye Decolorization in Anaerobic/aerobic Sequencing Batch Reactors

The decolorization kinetics of Remazol Brilliant Violet 5R (RBV-5R) and Remazol Black B (RB-B) (mono- and diazo reactive dyes, respectively) was investigated in the first 9 h (anaerobic phase) of a 24-h cycle anaerobic/aerobic sequencing batch reactor (SBR). Two distinct, successive decolorization periods were observed for both dyes, apparently due to different decolorization mechanisms. The apparent first-order rate constants were much lower for the second periods. First-order kinetics were apparently followed for both periods of RBV-5R but not for the first decolorization period of RB-B, possibly due to the occurrence of mass transfer limitations.     

类胡萝卜素合成的相关基因及其基因工程

类胡萝卜素具有多种生物功能,尤其在保护人类健康方面起着重要的作用,如它们是合成维生素A的前体,能够增强人体免疫力和具有防癌抗癌的功效。人体自身不能合成类胡萝卜素,必须通过外界摄入;但类胡萝卜素在许多植物中含量较低,并且很难用化学方法合成。随着类胡萝卜素生物合成途径的阐明及其相关基因的克隆,运用基因工程手段调控类胡萝卜素的生物合成已成为可能。本文综述了微生物和高等植物类胡萝卜素生物合成途径中相关基因的克隆,以及运用这些基因通过异源微生物生产类胡萝卜素和提高作物类胡萝卜素含量的基因工程研究进展。     

Bacterial Decolorization of Azo Dyes by Rhodopseudomonas palustris

Summary The ability of Rhodopseudomonas palustris AS1.2352 possessing azoreductase activity to decolorize azo dyes was investigated. It was demonstrated that anaerobic conditions were necessary for bacterial decolorization, and the optimal pH and temperature were pH 8 and 30–35 °C, respectively. Decolorization of dyes with different molecular structures was performed to compare their degradability. The strain could decolorize azo dye up to 1250 mg l⁻¹, and the correlation between the specific decolorization rate and dye concentration could be described by Michaelis–Menten kinetics. Long-term repeated operations showed that the strain was stable and efficient during five runs. Cell extracts from the strain demonstrated oxygen-insensitive azoreductase activity in vitro.     

Decolorization of Synthetic Dyes by Aspergillus flavus

A problem of paramount importance that has attracted the attention of environmental biologists is the discharge of highly colored effluents into the environment by various industries, which use a wide range of synthetic dyes. The existing chemical methods for dye degradation are not only expensive but also contributes to secondary pollution due to high dose of the chemicals used. Hence an alternative is to exploit the potential of microorganisms to alleviate this problem. The current paper deals with the isolation, characterization, and sugar utilization for better growth of Aspergillus flavus, a marine fungus from the Bay of Bengal. The goal is to assess the bioremediation potential of a variety of synthetic, paper mill, and color photography dyes. A correlation between the amount of sugar used, biomass, and quality of protein produced was observed. This fungus is capable of reducing between 80% and 90% of synthetic dyes and 100% color photography effluents within 3 to 7 days, and 8 days, respectively. Significant effect of carbon sources was observed in the decolorization of the synthetic dye crystal violet, up to 90% in 3 to 7 days, by Aspergillus flavus. The organism showed better growth with fructose as the sole carbon source for the least sugar consumption. Therefore, this fungus can be used as an economical and eco-friendly tool to minimize the pollution by industries to a significant extent.     

植物抗病毒基因工程的研究进展

自１９８６ 年首次成功获得转基因抗病毒植物以来,植物抗病毒基因工程的研究与应用在世界各地蓬勃发展。本文综述了国内外在这方面的研究进展及最新成就,以及此领域的存在问题和前景展望。     

斑马鱼基因工程的研究进展

对国内外斑马鱼基因工程研究进展。包括最近获得的大批转基因斑马鱼品系、靶向筛选的转基因斑马鱼、斑马鱼转基因技术的发展和斑马鱼基因工程的热点问题与应用前景进行了综述。指出我国已建立日趋成熟的斑马鱼转基因技术、细胞核移植技术和染色体组操作技术,具有斑马鱼细胞遗传学和胚胎学基础,我国有望在不久的将来获得定向整合的基因工程斑马鱼,并推动生物技术应用研究领域的进步和发展。     

Bioremediation of Textile Azo Dyes by Aerobic Bacterial Consortium Aerobic Degradation of Selected Azo Dyes by Bacterial Consortium

An aerobic bacterial consortium consisting of two isolated strains (BF1, BF2) and a strain of Pseudomonas putida (MTCC1194) was developed for the aerobic degradation of a mixture of textile azodyes and individual azodyes at alkaline pH (9-10.5) and salinity (0.9-3.68 g/l) at ambient temperature (28 +/- 2 degrees C). The degradation efficiency of the strains in different media (mineral media and in the Simulated textile effluent (STE)) and at different dye concentrations were studied. The presence of a H2O2 independent oxidase-laccase (26.5 IU/ml) was found in the culture filtrate of the organism BF2. The analysis of the degraded products by TLC and HPLC, after the microbial treatment of the dyes showed the absence of amines and the presence of low molecular weight oxidative degradation products. The enzymes present in the crude supernatant was found to be reusable for the dye degradation.     

藜芦醇和吐温80对白腐菌产木质素降解酶的影响及在偶氮染料脱色中的作用

担子菌PM2在限氮液体培养下,分泌木质素过氧化物酶和锰过氧化物酶;藜芦醇、吐温 80的补充,提高了该菌锰过氧化物酶的产生,获得的最大锰过氧化物酶Mnp酶活为254.2u/L、190.2 u/L,分别是对照的3.4倍和2.5倍。选择三种偶氮染料,在染料体系下,进一步分析藜芦醇、吐温 80对担子菌PM2产过氧化物酶及染料脱色的影响。结果表明,担子菌PM2分泌的锰过氧化物酶Mnp与染料脱色有关,脱色程度受其分子结构特征影响;吐温80的补充,更有利于染料的脱色降解,48h后三种染料均可达到80%以上的脱色率。