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Immobilization of “Disguised” yeast in chemically crosslinked chitosan beads
Author(s) -
Freeman Amihay,
Dror Yael
Publication year - 1994
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260440909
Subject(s) - chitosan , glutaraldehyde , yeast , glyoxal , castor oil , bead , chemistry , carboxymethyl cellulose , cellulose , bioreactor , chromatography , ethanol , polymer chemistry , nuclear chemistry , biochemistry , organic chemistry , materials science , composite material , sodium
Abstract A new simple method for the preparation of chemically crosslinked chitosan beads is presented. It consists of the dropwise addition of 2–3% (w/v) low molecular weight chitosan solution containing 2% (w/v) glyoxal in 1% (w/v) tetrasodiumdiphosphate, pH 8.0. Immobilized viable baker's yeast ( Saccharomyces cerevisiae ) could be obtained via gel entrapment within the new beads when means preventing their direct contact with soluble chitosan were provided, “disguising” the cells until gelation and crosslinking were completed. Such means included cell suspension in castor oil or mixing with carboxymethyl‐cellulose powder. Application of these means was shown to be necessary, as cells exposed to soluble chitosan immediately lost their viability and glycolytic activity. Yeast disguised in castor oil was also protected from bead reinforcement by glutaraldehyde treatment, significantly strengthening bead stability while operating under acidic conditions. This capability was demonstrated by continuous ethanol production by chitosan entrapped yeast. © 1994 John Wiley & Sons, Inc.