Repeated solid-phase fermentation and extraction for enzyme production

Solid-phase fermentation has been found to have a much higher productivity than the popular liquid submerged fermentation in producing cellulase enzym es. The highest reported productivity in the literature for cellulases by T richoderma cultures in submerged fermentation is 158 filter payer units (FP U)/(h.L) of fermenting liquid. From preliminary experiments of solid-phase fermentation in 1000-mL flasks, a productivity of 234 FPU of cellulases/(h. L) of solid-bed volume was obtained. When two novel techniques-pressure pul sation and repeated extraction-were applied, a productivity of 806 FPU/(h.L ) was achieved. The same techniques also greatly enhanced the productivity of other enzymes by fungal cultures in solid-phase fermentation.