Biosynthesis of protein by microscopic fungi in solid state fermentation. III. The effect of different cultivation methods and various media on protein biosynthesis by Aspergillus oryzae A. or. 11

Abstract

AbstractThe effect of the culture method in solid medium and the influence of starch‐containing raw materials on the yield of fungal protein biosynthesis were studied. Three procedures (laboratory bioreactor method, tray method and pile method) gave satisfactory results. Protein yields amounted to 5.0–5.9 g/100 g of starting medium d.m. upon utilization of 20.9–24.1 g carbohydrates. The procedure involving the use of a fermenter with a mixer afforded protein yields by about 50% lower as compared with the three above‐mentioned procedures, and therefore it requires technical improvement.As a result of fungal culture using various starch‐containing raw materials, the protein content in post‐culture products increased by 46–88%, as compared with starting medium. The contents of 13 amino acids (including some exogenous ones which increased by 52–82%) in post‐culture products substantially rose (by 34–63%). The post‐culture products exhibited proteolytic activity (1260–3500 HU/g of d.m.).The kind of the source of starch evidently influenced protein biosynthesis. Media based on potatoes afforded the greatest increases in protein (5.8–5.9 g/100 g of starting medium d.m.), and those containing coarse rye meal and milling by‐products — the smallest ones (4.5–4.6 g/100 g of starting medium d.m.).