Biosynthesis of protein by microscopic fungi in solid state fermentation. II. Optimization of aspergillus oryzae A. or. 11 cultivation for protein enrichment of starchy raw materials

Study was made of the effect of medium humidity, source and dose of nitrogen, dose of phosphorus, dose of inoculum and aeration on protein biosynthesis by strain Aspergillus oryzae A. or. 11 in solid state fermentation. It was found that for a maximal protein yield the medium ought to contain about: 60% of water, 36% of starchy raw materials d. m. (e.g. 28.8% of coarse rye meal and 7.2% of beet pulp), 0.85% of nitrogen sources (1.6% of (NH₄)₂SO₄ and 1.1% of urea), and 0.35% of phosphorus source (1.3% of KH₂PO₄). pH of medium should be near 6.5. The dose of inoculum should not be lower than 10⁸ spores/100 g medium. The duration of culture ought to be 20–22 h at 30–35°C, with aeration at least 40 dm³ of air/h × 1000 g medium. Under these conditions the protein yield is about 6.0–6.3 g/100 g of starting medium d.m. at the cost of utilization of about 25 g total carbohydrates.