Optimization of fermentation conditions of CotA laccase from recombinant Escherichia coil Article

cited authors

  • Zhang, N; Wang, C; Zhao, M; Zhang, Y

fiu authors

abstract

  • CotA laccase is important for its applications in industries such as environmental protection, food industry, and paper biobleaching. A recombined expression vector pET-22b(+) /CotA was transferred into Escherichia coli BL21 (DE3). The effects of induction expression conditions and the fermentation medium on the production of CotA laccase by recombinant E. coli were investigated using one factor method and orthogonal design. The strain was cultured first under the following conditions: 0.6 mmol L -1 copper ions, 1 g L -1 glucose as carbon source, 15 g L -1 tryptone and 2 g L -1 ammonium sulfate as nitrogen source, inoculum concentration 10%, temperature 37 °C and shaking speed 200 r/min. IPTG was added to the culture at 1.0 mmol L -1 when the D 600 nm of culture reached 1.0. After 12 h cultivation at 25 °C, the highest laccase yield was obtained. The laccase activity of the extraction of the fermentation broth after optimization (3 526 U mL -1) was 2.96 times than that before optimization (only 1 190 U mL -1). The optimum temperature and pH of the enzyme activity were 45 °C and 7.2, respectively. The decolorization rate of Remazol brilliant blue R (RBBR) by CotA laccases reached over 90%. The result indicated that the CotA laccase had the potential to be industrial enzyme. Fig 6, Tab 3, Ref 17.

publication date

  • August 25, 2011

Digital Object Identifier (DOI)

start page

  • 563

end page

  • 567

volume

  • 17

issue

  • 4