Immobilized salt-tolerant yeasts: application of a new polyethylene-oxide support in a continuous stirred-tank reactor for flavour production

J Biotechnol. 2001 Jun 15;88(2):129-39. doi: 10.1016/s0168-1656(01)00264-4.

Abstract

Immobilization of salt-tolerant yeasts considerably decreases the total time required for the flavour development in soy-sauce processes. For immobilization of cells, alginate gel is mostly used as support material. However, alginate is not very suitable for use in soy-sauce processes because alginate is sensitive to abrasion and chemically unstable towards the high salt content of the soy-sauce medium. In contrast, a newly developed polyethylene-oxide gel seems to be more suitable, but this gel has not been used so far for flavour production in a bioreactor with a high salt content. Therefore, this gel was applied with immobilized salt-tolerant yeasts in a continuous stirred-tank reactor, containing more than 12.5% (w/v) salt. In this reactor, the polyethylene-oxide gel particles did not show any abrasion for several days, while alginate gel beads were already destroyed within 1 day. In addition, the polyethylene-oxide gel particles with immobilized salt-tolerant yeasts Candida versatilis and Zygosaccharomyces rouxii showed a good flavour production. From this work, it was concluded that the application of polyethylene-oxide gel in long-term soy-sauce processes is attractive in the case the sticking together of polyethylene-oxide gel particles can be controlled.

Publication types

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

MeSH terms

  • Alginates / chemistry
  • Bioreactors
  • Candida / physiology
  • Cells, Immobilized
  • Ethanol / metabolism
  • Gels
  • Glucuronic Acid
  • Guaiacol / analogs & derivatives*
  • Guaiacol / metabolism
  • Hexuronic Acids
  • Industrial Microbiology / instrumentation
  • Industrial Microbiology / methods*
  • Polyethylene Glycols / chemistry*
  • Salts / chemistry
  • Salts / metabolism
  • Yeasts / physiology*
  • Zygosaccharomyces / physiology

Substances

  • Alginates
  • Gels
  • Hexuronic Acids
  • Salts
  • Ethanol
  • Polyethylene Glycols
  • Guaiacol
  • Glucuronic Acid
  • 4-ethylguaiacol