Immobilized soy-sauce yeasts: development and characterization of a new polyethylene-oxide support.
Entrapment of cells in alginate gel is a widely used mild immobilization procedure. However, alginate gel is not very suitable for use in long-term continuous soy-sauce processes because alginate is sensitive to abrasion and chemically unstable towards the high salt content of soy-sauce medium. Therefore, a chemically crosslinked polyethylene-oxide gel was used instead. The disadvantage of this gel was that due to the crosslinking reaction, the viability of the cells after immobilization was poor. For this reason, a new mild procedure for immobilizing soy-sauce yeasts in polyethylene-oxide gel was developed, resulting in high survival percentages of the soy-sauce yeasts Zygosaccharomyces rouxii and Candida versatilis. This newly developed polyethylene-oxide gel, unlike alginate gel, appeared not to be sensitive to abrasion, even in the presence of high salt concentrations. Therefore, we concluded that this newly developed polyethylene-oxide gel is more suitable than alginate gel for use as immobilization material in long-term processes with a high salt content, like soy-sauce processes.
van der Sluis
C
C
Department of Agrotechnology and Food Sciences, Food and Bioprocess Engineering Group, Wageningen University, P.O. Box 8129, 6700 EV, Wageningen, The Netherlands. catrinus.vandersluis@algemeen.pk.wau.nl
Mulder
A N
AN
Grolle
K C
KC
Engbers
G H
GH
ter Schure
E G
EG
Tramper
J
J
Wijffels
R H
RH
D002175:Candida / Q000378:metabolism*; D011092:Polyethylene Glycols / Q000737:chemistry*; D013025:Glycine max / Q000382:microbiology*; D020068:Zygosaccharomyces / Q000378:metabolism*
D011092:Polyethylene Glycols