Cereal Chem 43:658 - 668.  |  VIEW ARTICLE

Enzymatic Production of Glucose Syrup from Grains and Its Use in Fermentations.

M. C. Cadmus, L. G. Jayko, D. E. Hensley, H. Gasdorf, and K. L. Smiley. Copyright 1966 by the American Association of Cereal Chemists, Inc. 

Starch in ground samples of whole corn, wheat, and sorghum was enzymatically converted to D-glucose in 90-95% yield with a combination of alpha-amylase from either barley malt or Bacillus subtilis and gluco- amylase from Aspergillus species. Gas-liquid chromatography of the trimethylsilyl derivatives of the syrup showed that maltose and isomaltose comprised less than 10% of the total sugar. Syrups containing 20-25% D-glucose were produced in 24-48 hr. Approximately 20-25% of the original grain solids were recovered by filtration after enzymolysis. The nitrogen content of the recovered solids was about three times higher than the original grain. Some nitrogen was solubilized during enzymolysis and appeared in the syrups at a concentration of approximately 2 mg./ml. Two of the three strains studied, A. awamori NRRL 3112 and A. niger NRRL 3122, proved to be the most efficient in total starch-to-glucose conversion, and were low in transglucosidase activity. The syrups were employed for the production of several microbial polysaccharides, citric acid, fumaric acid, and 2-ketogluconic acid. Product yields equal to or surpassing those obtained with commercial D-glucose were realized.