EXOCELLULAR PRODUCT FORMATION BY MICROORGANISMS IN CONTINUOUS CULTURE. I. PRODUCTION OF 2:3‐BUTANEDIOL BY AEROBACTER AEROGENES IN A SINGLE STAGE PROCESS

Abstract

SUMMARY: A quantitative study of the growth and carbohydrate metabolism of Aerobacter aerogenes in continuous culture with particular reference to 2:3‐butanediol production is described. The effects of varying dilution rate, oxygen uptake rate, pH value, temperature and CO2 pressure were studied.The optimum pH value was 5·0°6·0. The optimum temperature was 35–37° with a dilution rate of 0·2 hr−1. The rate of sugar metabolism was decreased by raising the CO2 pressure.In continuous culture the maximum diol output rate/1. of working volume exceeded the greatest rate reported for batch culture by a factor of three. The maximum diol concentration and yield as a percentage of the theoretical maximum were lower in continuous culture than in batch culture. Reasons for this are given.Some variants of the parent organism were found in continuous cultures but they caused no change in the yield of butanediol. There was no sign of loss of butanediol‐producing ability by any of the cultures, some of which were maintained for 2,000 hr. For the first few generations the rate of production of butanediol actually increased.