STUDIES WITH BACILLUS POLYMYXA: IV NITROGEN REQUIREMENTS IN RELATION TO 2,3-BUTANEDIOL PRODUCTION FROM STARCH

Abstract

Yeast extract, casein hydrolysate, and a mixture of 13 to 20 ammo acids were found to be superior to simpler substances such as ammonium sulphate, urea, potassium nitrate, or asparagine as sources of nitrogen for Bacillus polymyxa in relation to production of 2,3-butanediol from starch The complex sources of nitrogen were more or less interchangeable for most, but not all strains of this organism with regard to effectiveness for diol production, but the addition of yeast extract to either casein hydrolysate or amino acids resulted in a slightly higher yield of diol and an increase in the diol/ethanol ratio from 2 to 2.6 or higher.The requirements of different strains for specific ammo acids varied somewhat, but the need for isoleucine and asparagine was common to the tour strains studied. A fairly good fermentation was obtained with the most efficient of these strains in a medium containing isoleucine, tyrosine, glycine, methionine, and asparagine after three days' incubation. The fermentation went to completion after five days with certain concentrations of these five acids an effect that was achieved in three days by the addition to these of eight other acids but not by the addition of ammonium sulphate. Suppression of diol production by omission of certain of these amino acids was marked at three days but was largely overcome at five. Cystine (in concentrations above: 0.0125%; was inhibitory to the four strains studied and phenylalanine (0.02%) to one, after three but not after five days.