EFFECTS OF SUBSTRATE PARTICLE-SIZE AND ALKALINE PRETREATMENT ON PROTEIN ENRICHMENT BY NEUROSPORA-SITOPHILA

The effects of solid-substrate characteristics (particle size, pretrea tment conditions) on microbial biomass protein production and cellulos e utilization by Neurospora sitophila (ATCC 36935) were investigated. Corn stover ground to various particle size fractions ( < 1 mm, 1-2 mm , 2-3 mm) was the test substrate. The pretreatment utilized sodium hyd roxide (0-0.15 kg/kg substrate, at 121 degrees C for 30 min) for delig nification and hemicellulose removal. Cellulose utilization by the fun gus and the crude protein production increased with decreasing substra te particle size and with increasing sodium hydroxide concentration in the pretreatment step. Under the best conditions, using < 1 mm substr ate particles treated with 0.15 kg NaOH/kg substrate, approx. 90% of t he initial cellulose was consumed by the fungus and the crude protein concentration in the dry product exceeded 50% by weight.