[Impact of fermentation system initial status on oscillations in very high gravity ethanol continuous fermentation process and analysis of fermentation efficiency improvement]

Sheng Wu Gong Cheng Xue Bao. 2010 May;26(5):604-9.
[Article in Chinese]

Abstract

Prior research reported the oscillatory behavior characterized by long period and high amplitude during high gravity continuous ethanol fermentations at the dilution rate of 0.027 h(-1). In this paper, high gravity continuous ethanol fermentations using Saccharomyces cerevisia at different dilution rates were carried out. Similar oscillations were observed when the dilution rate was switched to 0.04 h(-1). Both oscillatory and steady processes can be achieved at dilution rates of 0.027 or 0.04 h(-1), which depends on the initial status of the fermentation system. However, compared to steady process at the same dilution rate of 0.04 h(-1), the average residual sugar concentration was lowered by 14.8% for the oscillatory process, while the average ethanol concentration and productivity were increased by 12.6% and 12.3%, respectively. Further investigation revealed that besides the lag time, oscillatory processes were different from steady ones in kinetics because a higher specific growth rate can be achieved at the same residual sugar and ethanol concentrations (increased by 53.8% in average).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bioreactors / microbiology*
  • Carbohydrates
  • Ethanol / metabolism*
  • Fermentation*
  • Hypergravity
  • Saccharomyces cerevisiae / metabolism*

Substances

  • Carbohydrates
  • Ethanol