Fed-batch cultivation of Mucor indicus in dilute-acid lignocellulosic hydrolyzate for ethanol production

Biotechnol Lett. 2005 Sep;27(18):1395-400. doi: 10.1007/s10529-005-0688-2.

Abstract

Mucor indicus fermented dilute-acid lignocellulosic hydrolyzates to ethanol in fed-batch cultivation with complete hexose utilization and partial uptake of xylose. The fungus was tolerant to the inhibitors present in the hydrolyzates. It grew in media containing furfural (1 g/l), hydroxymethylfurfural (1 g/l), vanillin (1 g/l), or acetic acid (7 g/l), but did not germinate directly in the hydrolyzate. However, with fed-batch methodology, after initial growth of M. indicus in 500 ml enzymatic wheat hydrolyzate, lignocellulosic hydrolyzate was fermented with feeding rates 55 and 100 ml/h. The fungus consumed more than 46% of the initial xylose, while less than half of this xylose was excreted in the form of xylitol. The ethanol yield was 0.43 g/g total consumed sugar, and reached the maximum concentration of 19.6 g ethanol/l at the end of feeding phase. Filamentous growth, which is regarded as the main obstacle to large-scale cultivation of M. indicus, was avoided in the fed-batch experiments.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetic Acid / pharmacology
  • Benzaldehydes / pharmacology
  • Biomass
  • Cellulose / metabolism*
  • Ethanol / metabolism*
  • Fermentation / drug effects
  • Furaldehyde / analogs & derivatives
  • Furaldehyde / pharmacology
  • Galactose / metabolism
  • Hydrolysis
  • Lignin / metabolism*
  • Mannose / metabolism
  • Mucor / drug effects
  • Mucor / growth & development
  • Mucor / metabolism*
  • Mycology / methods*
  • Time Factors
  • Xylitol / metabolism
  • Xylose / metabolism

Substances

  • Benzaldehydes
  • Ethanol
  • 5-hydroxymethylfurfural
  • Cellulose
  • Lignin
  • Xylose
  • vanillin
  • Furaldehyde
  • Mannose
  • Acetic Acid
  • Xylitol
  • Galactose