Separation of the Substances from Yeast Extract to Accelerate Acetic Acid Production

(Studies on the Substances to Stimulate Acetic Acid Fermentation Part VI)

Abstract

(1) Accelerating effect for acetic acid fermentation employing No.2 strain accepted from National Institute of Fermentation Technology, Ibaraki-ken, was found in yeast extract, koji extract, sake cake, malt extract and molasses added into media. In paticular, yeast extract was most effective to reduce the lag time of the growth and increase the amount of acetic acid produced. (2) Effective substances in the yeast extract were separated into three fractions, an acidic, a basic and a neutral fraction with a chromatography employing Amberlite IR-120 (H⁺) and IR-4B (OH^-). Among the three fractions, an acidic fraction showed the most stimulative effect. It was confirmed that the stimulative effect was caused by the organic acids including lactic, pyroglutamic, and succinic acid, as the result of chemical analysis and microbial test. (3) Effective substances in neutral fraction were considered as glycerol, sucrose and ribose as the result of bioautography, gas chromatography and column chromatography on LC-R-3 ion exchange resin. From the amino acid composition in the basic fraction, it was estimated that the stimulative effect of this fraction was due to the amino acids including alanine, glutamic acid, and aspartic acid.