Optimization of culture medium composition for Mn-peroxidase and tyrosinase production during Reactive Black 5 decolourization by yeast Trichosporon akiyoshidainum

MARTORELL, MARÍA M; PAJOT, HIPÓLITO F; ROVATI, JOSÉ I; CASTRO, GUILLERMO R; CASTELLANOS, LUCÍA IC

Trivandrum

Congreso; New Horizons in Biotechnology; 2011

National Institute for Interdisciplinary Science and Technology- CSIR and Biotech Research Society of India

Decolourization and degradation of diazo Reactive Black 5 dye was carried out by yeast Trichosporon akiyoshidainum. A nine-factor Plackett-Burman design was employed for study and optimization of decolourization process and production of Mn-Peroxidase and tyrosinase activities. In the present study, 26 individual experiments were conducted and three responses were evaluated. Raising yeast extract concentration significantly enhances decolourization and Mn-Peroxidase production. Carbon and nitrogen sources, glucose and (NH4)2SO4, showed no significant effect on any response over the tested concentration range. Other culture medium components such as CaCl2 or MgSO4 could be excluded from the medium formula as they had no effect on the evaluated responses. Metal ions (Fe, Cu and Mn), showed different effects on decolourization or on enzymatic activities. Addition of cupper significantly enhanced Mn-P activity and decreased dye decolourization. On the contrary, iron had a positive effect on decolourization and no effect on enzymes production. Oddly, increasing manganese concentration had a positive effect on tyrosinase production but without affecting decolourization or Mn-Peroxidase activity. These results strongly suggest that dye decolourization should be regarded as a complex multi-enzymatic process, where optimal media composition should arise as a compromise between those optimal for each implied enzyme production.