title: Evaluation of Bacillus sp. MZS10 for decolorizing Azure B dye and its decolorization mechanism.
abstract: To evaluate decolorization and detoxification of Azure B dye by a newly isolated Bacillus sp. MZS10 strain, the cultivation medium and decolorization mechanism of the isolate were investigated. The decolorization was discovered to be dependent on cell density of the isolate and reached 93.55% (0.04 g/L) after 14 hr of cultivation in a 5 L stirred-tank fermenter at 2.0 g/L yeast extract and 6.0 g/L soluble starch and a small amount of mineral salts. The decolorization metabolites were identified with ultra performance liquid chromatography-tandem mass spectroscopy (UPLC-MS). A mechanism for decolorization of Azure B was proposed as follows: the C=N in Azure B was initially reduced to -NH by nicotinamide adenine dinucleotide phosphate (NADPH)-dependent quinone dehydrogenase, and then the -NH further combined with -OH derived from glucose to form a stable and colorless compound through a dehydration reaction. The phytotoxicity was evaluated for both Azure B and its related derivatives produced by Bacillus sp. MZS10 decolorization, indicating that the decolorization metabolites were less toxic than original dye. The decolorization efficiency and mechanism shown by Bacillus sp. MZS10 provided insight on its potential application for the bioremediation of the dye Azure B.
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China; School of Biological and Chemical Engineering, Nanyang Institute of Technology, Nanyang 473004, China.
authors: Huixing
authors: H
authors: Li
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
authors: Ruijing
authors: R
authors: Zhang
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China. Electronic address: ltang@jiangnan.edu.cn.
authors: Lei
authors: L
authors: Tang
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
authors: Jianhua
authors: J
authors: Zhang
authors: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China. Electronic address: maozg@jiangnan.edu.cn.
authors: Zhonggui
authors: Z
authors: Mao
mesh_terms: D001399:Azure Stains / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity; D001407:Bacillus / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002853:Chromatography, Liquid / Q000379:methods; D004396:Coloring Agents / Q000378:metabolism; D007220:Industrial Waste; D007700:Kinetics; D013058:Mass Spectrometry / Q000379:methods; D015394:Molecular Structure; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D045868:Sorghum / Q000187:drug effects; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001399:Azure Stains; D004396:Coloring Agents; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D009243:NAD; D009249:NADP; C025819:Azure B
keywords: Azure B; Bacillus sp.; decolorization; graphy-tandem mass spectroscopy; phytotoxicity; ultra performance liquid chromato