PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: IX. THE EFFECT OF VARIOUS NUTRIENT MATERIALS ON THE FERMENTATION OF STARCH BY AEROBACILLUS POLYMYXA

Abstract

Wheat starch is a poor medium for fermentation by Aerobacillus polymyxa. The solubles recovered from the separation of starch and gluten in patent flour enhance the fermentation but not as effectively as the similar fraction from whole wheat flour. Addition of supplements is necessary for a satisfactory yield of products in a reasonable length of time. Wheat gluten has no stimulatory effect but bran and shorts are both effective, the latter being slightly superior. An 8% starch medium fortified with the solubles from whole wheat required a 2.5% supplement of shorts to bring fermentation by A. polymyxa to 90% completeness in 72 hr.Of the various supplements tested, a 1% addition of malt sprouts proved to be the most effective, fermentation being 90% complete in 72 hr. Shorts, bran, Cerogras (dehydrated young oats), alfalfa, soya beans, yeast extract, and corn-steep liquor follow in order of decreasing effectiveness.The solubles from whole wheat when ashed have no beneficial effects on the fermentation of starch by A. polymyxa.