STUDIES ON THE ANAEROBIC DISSIMILATION OF GLUCOSE BY BACILLUS SUBTILIS (FORD'S TYPE)

Abstract

Bacillus subtilis (Ford's type) was able to fix only 3% of the NaHC¹⁴O₃ added during anaerobic dissimilation of glucose, under conditions where Serratia marcescens and Aerobacter aerogenes fixed 38% and 54% respectively. The carbon-14 was found mainly in succinic acid, lactic acid carboxyl, and formic acid, in decreasing order of specific activity. Similar experiments with labelled formate showed it to be relatively inert, most of it being recovered unchanged. Acetate was readily metabolized by B. subtilis during the fermentation of glucose with a marked increase in the amount of 2,3-butanediol and ethanol formed, while the amount of glycerol was decreased to less than one-tenth of the normal value. Experiments with CH₃C¹⁴OONa proved that the acetate was reduced to ethanol, only traces of acetate carbon being found in 2,3-butanediol or lactic acid. Fermentation of glucose-1-C¹⁴ gave 2,3-butanediol and lactic acid labelled in the methyl groups and glycerol labelled mainly in the primary alcohol groups; only a small part of the carbon-14 being found in carbon dioxide.