Optimization of Culture Conditions During the Solid-State Fermentation of Tea Residue Using Mixed Strains

In the present research mixed strains of Bacillus subtilis, Aspergillus niger and Saccharomyces cerevisiae were used for solid state fermentation of tea residue. Fermentation conditions were optimized using response surface methodology as: temperature 29.24%, water content 54.14%, fermentation time 5.58 days, B. subtilis: A. niger: S. cerevisiae inoculum ratio 1:1:2. At optimal conditions there was a significant increase in crude protein (CP), the reducing sugar, cellulose activity of 19.32%, 39.5%, 33.3% respectively in comparison with pre-fermentation.