METHOD FOR PRODUCTION OF CITRIC ACID, ALPHA-AMYLASE AND GLUCOAMYLASE

摘要

FIELD: microbiological industry, in particular production of citric acid and acid-resistant α-amylase and glucoamylase enzymes.;SUBSTANCE: claimed method includes starch and maize flour hydrolysis in ratio of 1:7-1:40 with bacterial α-amylase enzyme preparation at elevated temperature and pressure to obtain value of carbon source dextrose equivalent not more than 30; addition of nitrogen organic source and mineral salts such as copper (II), zinc, cobalt (II) sulfates in amount of (0.5-1.0)x10^-3, (1.5-3.5)x10^-3, (1.5-4.5)x10^-3 g/dm³, respectively, iron (II) to starch and maize flour hydrolyzate followed by medium fermentation with acid-forming fungi Aspergillus niger. Than hydrolyzate is diluted with sterile water to obtain fermentable sugar content of 120-140 g/dm³ and carbon and nitrogen organic source in ratio of (50-60):1, respectively. Method of present invention males in possible to convert sugar to citric acid with yield of 79.3-83.1 % and to obtain acid-resistant α-amylase and glucoamylase enzymes having activities of 2.50-3.50 U A-C/cm³ and 80.2-147.4 U Gl-C/cm³, respectively.;EFFECT: method for production of citric acid, α-amylase and glucoamylase with increased yield.;1 tbl, 4 ex