摘要：本文詳細介紹了菌株GS-4-08對目標染料-甲基橙的厭氧還原特點和影像因素。由于偶氮染料廢水的好氧穩定性特點，應用傳統的活性污泥法處理效果不佳。針對這種現象，本文力求篩選出一株高效降解偶氮染料的細菌，并且對其特性進行一系列相關的研究。

　　　經過常規的生理、生化以及分子生物學鑒定，該菌株是克雷柏氏桿菌屬的一種，用于研究偶氮染料的脫色效果。這種細菌通過革蘭氏染色法的形態描述和16S rRNA基因分析被鑒定為克雷柏氏桿菌的一員。在適當電子供體存在下，這種細菌在偶氮染料脫色和產氫方面具有良好的能力。該菌種對甲基橙厭氧脫色的最佳pH值，溫度，電子供體類型及濃度分別為7, 35oC and 20 mM 的蔗糖。

　　　研究結果表明即使在0.5 mM的高濃度的甲基橙存在條件下，這種菌株都能夠有效的將電子供體轉為H2以及產生其他有用產品（例如：乙醇和乙酸），表明了這種細菌對染料的高耐受力。在偶氮染料的脫色過程中，有效的將電子供體轉化成H2不僅能夠有效的抑制揮發性脂肪酸 (VFAs)的積累，同時還能夠回收能源物質。

　　　實驗結果表明由于菌株GS-4-08在偶氮染料脫色和生物產氫能力方面相當可觀，因此是一株潛在的可應用在印染廢水的處理工藝中的有效細菌。

關鍵詞：偶氮染料，細菌，脫色，生物產氫

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