Intergeneric protoplast fusion from improved cellulose and protein biomass yield

Penicillium funiculosum Thom MG-171 was used for the fusion technique with the standard Trichoderma reesei strain. Recombinants using the protoplast fusion technique with T. reesei RUT C-30 and P. funiculosum Thom MG-171 as parents, were produced. Fusants 34, 35, 36, and 37 exhibited banding patterns with polyacrylamide gel electrophoresis indicative of recommendation. Although the CMCase and FPase activities were still inferior as compared to the T. reesei parent B-glucosidase activity, which is the rate limiting step, was much higher. On the other hand, fusants 34,35, 36, and 37 were superior in CMCase and FPase activities compared to the P. funiculosum MG-171 parent strain but had lower B- glucosidase activities. Optimization of fermentation conditions showed that generally higher CMCase, FPase and B-glucosidase and biomass proteins were obtained at an initial pH of 6.0 at 30 deg C. Statistically, the enzyme and biomass protein production were significantly affected by pH substrates. Among the fusants, fusant 37 gave the better cellulase activity. Rice straw was substrate for enzyme production while corn cobs gave the best results for biomass protein. With the results of this study, an initial pH of 6.0 and temperature of 30 deg C, would be optimal for growth and enzyme production. Cellulases were not detected on the first day of fermentation. Maximum production of CMCase activity was obtained at 96 hours while B-glucosidase had maximum production at 120 hours. This time period also corresponded to the maximum growth period. The results in this study in connection with the availability of the raw materials indicate that the fusant strains may be used for the development of a simple technology for microbial transformation of agricultural residues into enzymes and protein enriched feed since their high transport costs favor small fermentation plants. Worldwide, microbial biomass is potentially abundant and could be cheaper than single cell proteins produced as the major product.