摘要：本文详细介绍了菌株GS-4-08对目标染料-甲基橙的厌氧还原特点和影像因素。由于偶氮染料废水的好氧稳定性特点，应用传统的活性污泥法处理效果不佳。针对这种现象，本文力求筛选出一株高效降解偶氮染料的细菌，并且对其特性进行一系列相关的研究。
经过常规的生理、生化以及分子生物学鉴定，该菌株是克雷柏氏杆菌属的一种，用于研究偶氮染料的脱色效果。这种细菌通过革兰氏染色法的形态描述和16S rRNA基因分析被鉴定为克雷柏氏杆菌的一员。在适当电子供体存在下，这种细菌在偶氮染料脱色和产氢方面具有良好的能力。该菌种对甲基橙厌氧脱色的最佳pH值，温度，电子供体类型及浓度分别为7, 35oC and 20 mM 的蔗糖。
研究结果表明即使在0.5 mM的高浓度的甲基橙存在条件下，这种菌株都能够有效的将电子供体转为H2以及产生其他有用产品（例如：乙醇和乙酸），表明了这种细菌对染料的高耐受力。在偶氮染料的脱色过程中，有效的将电子供体转化成H2不仅能够有效的抑制挥发性脂肪酸 (VFAs)的积累，同时还能够回收能源物质。
实验结果表明由于菌株GS-4-08在偶氮染料脱色和生物产氢能力方面相当可观，因此是一株潜在的可应用在印染废水的处理工艺中的有效细菌。
关键词：偶氮染料，细菌，脱色，生物产氢
Abstract：A facultative anaerobic bacteria strain GS-4-08, isolated from an anaerobic sequence batch reactor for simulated dye wastewater treatment, was investigated for azo-dye decolorization. This bacterium was identified as a member of Klebsiella oxytoca based on Gram staining, morphology characterization and 16S rRNA genes analysis.
It exhibited good ability in simultaneous azo dye decolorization and H2 production in the presence of appropriate electron donor (ED). The optimum pH, temperature and ED type and concentration for anaerobic decolorization of methyl orange (MO) by this stain were 7, 35oC and 20 mM of sucrose, respectively. This strain was found to be able to efficiently convert ED into H2 and other valuable products (e.g., ethanol and acetate) during azo dye decolorization even at a high MO concentration of 0.5 mM, indicating a high MO tolerability.
This efficient bio-hydrogen production from ED can not only avoid the inhibition of accumulated volatile fatty acids (VFAs) during MO decolorization, but also recover energy at the same time. Finally, a possible co-metabolism mechanism of MO decolorization and H2 production by genus GS-4-08 was proposed based on the analysis of intermediate and end products.
These results show that Klebsiella oxytoca GS-4-08 was a powerful bacterium for simultaneous dye decolorization and H2 production, and can be potentially applied in dye wastewater treatment.
Keywords: azo dye，bacteria，decolorization，bio-hydrogen production
