Decolorization of recombinant laccase from Bacillus subtilis

Bacterial decolorization is associated with involvement of various enzymes such as lignin peroxidase, laccase, azoreductase and biotransformation enzymes. Especially, bacterial laccase plays an important role in the decolorization process. Hereby, the broad substrate range makes laccases candidates for many industrial and biotechnological applications, such as bioremediation, decolorization of synthetic dyes, and biosensors. In this research, the recombinant laccase was trialed for its ability in ındustrial dye decolorization. The laccase-producing bacterial strain was isolated from Petrol-contaminated soils in Istanbul. In this research, the laccase gene was cloned from Bacillus subtilis and efficiently expressed in Escherichia coli BL21DE3 in a biologically active form. A dye decolorization experiment was conducted using six dyes, Turquoise blue Hf6 (λmax=613nm), Remazol black R.B (λmax=595nm), Remazol Brilliant Red BB (λmax=590nm), Coomassie brilliant blue (595nm), Crystal violet (570nm), Methyl red (520nm). The reaction mixture contained 0.1 M citrate_phosphate buffer (pH 6.0), dye (4 mM), purified laccase (100 U), and the CuSo4 (0.1 mM). The reaction incubated at 50 °C under mild shaking conditions. The control samples were run in parallel without the addition of laccase. After 6 hours of incubation at 50 ° C in the test tubes, significant differences wereobserved in the control tubes at pH 7. Acknowledgment:The authors thank Pamukkale University, Scientific Research Project Funding (PAÜBAP) for their financial support [Project number: 2016FEBE043].

Keywords:

Bacillus suptilis , Decolorization , Laccase , E.coli.