Guo Guang, Tian Fang, Zhang Can, Liu Tingfeng, Yang Feng, Hu Zhixin, Liu Chong, Wang Shiwei, Ding Keqiang
College of Environmental Engineering, Nanjing Institute of Technology, Nanjing, 211167, China.
Center for Disease Prevention and Control of Chinese PLA, Beijing, 100071, China.
Water Sci Technol. 2019 Jun;79(11):2036-2045. doi: 10.2166/wst.2019.210.
To obtain a bacterial consortium that can degrade azo dyes effectively, a bacterial consortium was enriched that can degrade Metanil yellow effectively. After 6 h, 96.25% Metanil yellow was degraded under static conditions by the bacterial consortium, which was mainly composed of Pseudomonas, Lysinibacillus, Lactococcus, and Dysgonomonas. In particular, Pseudomonas played a main role in the decolorization process. Co-substrate increased the decolorization rate, and yeast powder, peptone, and urea demonstrated excellent effects. The optimal pH value and salinity for the decolorization of azo dyes is 4-7 and 1% salinity respectively. The bacterial consortium can directly degrade many azo dyes, such as direct fast black G and acid brilliant scarlet GR. Azo reductase activity, laccase activity, and lignin peroxidase activity were estimated as the key reductase for decolorization, and Metanil yellow can be degraded into less toxic degradation products through synergistic effects. The degradation pathway of Metanil yellow was analyzed by Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry, which demonstrated that Metanil yellow was cleaved at the azo bond, producing p-aminodiphenylamine and diphenylamine. These findings improved our knowledge of azo-dye-decolorizing microbial resources and provided efficient candidates for the treatment of dye-polluted wastewaters.
为了获得能够有效降解偶氮染料的细菌群落，富集了一种能够有效降解酸性金黄G的细菌群落。6小时后，该细菌群落在静态条件下对酸性金黄G的降解率达到96.25%，该细菌群落主要由假单胞菌属、赖氨酸芽孢杆菌属、乳球菌属和 Dysgonomonas 组成。特别是，假单胞菌在脱色过程中起主要作用。共底物提高了脱色率，酵母粉、蛋白胨和尿素表现出优异的效果。偶氮染料脱色的最佳pH值和盐度分别为4-7和1%盐度。该细菌群落可以直接降解许多偶氮染料，如直接耐晒黑G和酸性大红GR。测定了偶氮还原酶活性、漆酶活性和木质素过氧化物酶活性作为脱色的关键还原酶，酸性金黄G可通过协同作用降解为毒性较小的降解产物。通过傅里叶变换红外光谱和气相色谱-质谱联用仪分析了酸性金黄G的降解途径，结果表明酸性金黄G在偶氮键处断裂，生成对氨基二苯胺和二苯胺。这些发现增进了我们对偶氮染料脱色微生物资源的了解，并为处理染料污染废水提供了有效的候选菌株。
