Karim Md Ekramul, Dhar Kartik, Hossain Md Towhid
Department of Microbiology, Faculty of Biological Sciences, University of Chittagong, Chittagong 4331, Bangladesh.
Environmental Biotechnology Division, National Institute of Biotechnology, Dhaka 1349, Bangladesh.
J Genet Eng Biotechnol. 2018 Dec;16(2):375-380. doi: 10.1016/j.jgeb.2018.02.005. Epub 2018 Feb 22.
Dyeing effluents have become a vital source of water pollution. Due to the xenobiotic properties and toxicity to all life forms including humans, removal of undesirable color and associated toxicity is crucial. In this study, five dye decolorizing bacteria were isolated from dyeing effluent using selective enrichment culture in Bushnell-Haas (BH) medium amended with co-substrate (i.e. glucose, yeast extract) and 100 mg L of each commercially available reactive dyes Novacron Orange FN-R, Novacron Brilliant Blue FN-R, Novacron Super Black G, Bezema Yellow S8-G and Bezema Red S2-B. The isolated bacteria were identified and assigned as sp., sp., sp., sp. and sp. based on their phenotypic (cultural, morphological, physiological and biochemical characteristic) observation. The dye decolorization efficiency was estimated spectrophotometrically up to 6 days of static incubation at 37 °C and observed that all of the isolates were unable to induce decolorization in absence of co-substrate. In case of monoculture, decolorization percentage varies from no visible decolorization (Bezema Red S2-B by Ek-5) to highest 90% decolorization (Novacron Brilliant Blue FN-R by Ek-13) whereas the decolorization percentage of bacterial consortium varies from 65% (Bezema Yellow S8-G) to 90% (Novacron Brilliant Blue FN-R and Novacron Super Black G). The study outlines the co-substrates mediated decolorization process where bacterial consortium proved as efficient dye decolorizer than that of the monocultures. This finding confers possibility of using novel microbial consortium for biological treatment of disreputable dyeing effluents.
印染废水已成为水污染的一个重要来源。由于其具有外源性特性且对包括人类在内的所有生命形式都有毒性，去除其中的不良颜色和相关毒性至关重要。在本研究中，使用添加了共底物（即葡萄糖、酵母提取物）以及100mg/L每种市售活性染料（诺瓦克隆橙FN-R、诺瓦克隆艳蓝FN-R、诺瓦克隆超级黑G、贝泽马黄S8-G和贝泽马红S2-B）的布什内尔-哈斯（BH）培养基，通过选择性富集培养从印染废水中分离出五株染料脱色细菌。根据其表型（培养、形态、生理和生化特征）观察，将分离出的细菌鉴定并归类为[具体细菌名称1]、[具体细菌名称2]、[具体细菌名称3]、[具体细菌名称4]和[具体细菌名称5]。在37°C下静态培养6天，通过分光光度法估算染料脱色效率，观察到在没有共底物的情况下，所有分离株均无法诱导脱色。在单一培养的情况下，脱色率从无可见脱色（Ek-5对贝泽马红S2-B）到最高90%脱色（Ek-13对诺瓦克隆艳蓝FN-R）不等，而细菌混合培养物的脱色率从65%（贝泽马黄S8-G）到90%（诺瓦克隆艳蓝FN-R和诺瓦克隆超级黑G）不等。该研究概述了共底物介导的脱色过程，其中细菌混合培养物被证明是比单一培养物更有效的染料脱色剂。这一发现为使用新型微生物混合培养物对声名狼藉的印染废水进行生物处理提供了可能性。
