Ethanol fermentation characteristics of Thermoanaerobacter ethanolicus

Abstract

Thermoanaerobacter ethanolicus is an extreme thermophilic non-spore forming ethanol-producing anaerobic bacterium. Minimum nutrient requirements and optimum growth conditions have been established. An optimum yeast extract-glucose ratio for ethanol yield has also been determined. Initial medium pH, optimally 7.5-8.0, significantly affected the amount of ethanol formed. Maximum specific growth rate was found to be 0.22 h-1 at pH 7.5 and 69°C. Ethanol concentration up to 11 g l-1 at pH 7.5 and 69°C was used to characterize ethanol inhibition. The growth kinetics of T. ethanolicus were characterized in terms of environmental parameters. Substrate utilization, ethanol formation and inhibition by both sugar and ethanol were also quantified. © 1985.