Evaluation of Cerrena unicolor BCC 300 and their enzymes for decolorization of synthetic dyes

Abstract

The aim of this study was to evaluate the capability of few WRB to produce lignin-modifying enzymes in the presence of dyes and to establish parameters providing maximum and fast decolorization of selected dyes by crude laccase. In the submerged culti-vation in the glycerol-based medium supplemented with 0.3 mM synthetic dyes, Cerrena unicolor BCC300, Coriolopsis gallica BCC1184, and Trametes versicolor BCC13 produced 69.3-88.4 U/ml, 54.3-59.0 U/ml, and 1.7-14.3 U/ml laccase, respectively, and demonstrated a high decolorization potential of Amaranth, Remazol Brilliant Blue R, and Indigo carmine. Involvement of laccase in these dyes decolorization was assessed and proved using the crude laccase obtained from the C. unicolor BCC300 culture liquid. Against Amaranth, the C. unicolor BCC300 laccase was most effective at pH 6-7, toward Indigo carmine at pH 6, whereas the decolorization of RBBR occurred at a maximum rate at pH 5. The decolorization activity by the enzyme decreased with increasing dye concentration. Nevertheless, it completely decolorized 0.08% RBBR and Indigo carmine after 24 h incubation. Amaranth was more resistant to the laccase action and only 55% of dye was decolorized after 24 h incubation. Concentration of laccase of 1 U/ml was sufficient to completely decolorize RBBR and Indigo carmine. However, increasing the enzyme concentration to 3 and 10 U/ml enhanced the rate of decolorization. Overall, the isolated from C. unicolor BCC300 crude laccase showed catalytic properties required for their biotechnological applications.