Efficient secretory production of CotA-laccase and its application in the decolorization and detoxification of industrial textile wastewater

• Published in: Environmental science and pollution research international Vol. 22; no. 12; pp. 9515 - 9523
• Main Authors: Guan, Zheng-Bing, Shui, Yan, Song, Chen-Meng, Zhang, Ning, Cai, Yu-Jie, Liao, Xiang-Ru
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2015; Springer Nature B.V
• Subjects: Acetosyringone; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bacillus pumilus; Bacillus subtilis; Bacillus subtilis - enzymology; Bacillus subtilis - genetics; Bacillus subtilis - metabolism; Bacteria; Bioavailability; Biological treatment; Bioreactors; Cloning; Coloring Agents - metabolism; Decoloring; Decolorization; Deoxyribonucleic acid; Detoxification; DNA; Dyes; E coli; Earth and Environmental Science; Ecotoxicology; Effluent treatment; Effluents; Environment; Environmental Chemistry; Environmental Health; Enzymes; Escherichia coli; Escherichia coli - genetics; Fisheries; High temperature; Industrial production; Industrial textiles; Laboratories; Laccase; Laccase - genetics; Laccase - metabolism; Land management; Peptides; Plasmids; Protein expression; Proteins; Recombinant; Research Article; Temperature; Textile Industry; Textile industry wastes; Textile industry wastewaters; Textiles; Toxicity; Waste Water Technology; Wastewater treatment; Water Management; Water Pollutants, Chemical - metabolism; Water Pollution Control; China; Textile wastewater; Signal peptide; Mediator; CotA-laccase
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-015-4426-6

Fungal laccases are typically unstable at high pH and temperature conditions, which limit their application in the decolorization of textile wastewater. By contrast, the highly stable bacterial laccases can function within a wider pH range and at high temperatures, thus have significant potential in treatment for textile wastewater. In our previous work, a thermo-alkali-stable CotA-laccase gene was cloned from Bacillus pumilus W3 and overexpressed in Escherichia coli . In this study, the robust CotA-laccase achieved efficient secretory expression in Bacillus subtilis WB600 by screening a suitable signal peptide. A maximum CotA-laccase yield of 373.1 U/mL was obtained at optimum culture conditions in a 3-L fermentor. Furthermore, the decolorization and detoxification of textile industry effluent by the purified recombinant CotA-laccase in the presence and absence of redox mediators were investigated. Among the potential mediators that enhanced effluent decolorization, acetosyringone (ACS) was the most effective. The toxicity of the CotA-laccase-ACS-treated effluent was greatly reduced compared with that of the crude effluent. To the best of our knowledge, this study is the first to report on the heterologous expression of CotA-laccase in B. subtilis . The recombinant strain B. subtilis WB600-5 has a great potential in the industrial production of this bacterial enzyme, and the CotA-laccase-ACS system is a promising candidate for the biological treatment of industrial textile effluents.