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Effect of metal ion concentration on a biological reactor
Author(s) -
Ibbotson P. G.,
Spedding P. L.,
Otterburn M. S.
Publication year - 1990
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.260360706
Subject(s) - metal ions in aqueous solution , chemistry , ion , nad+ kinase , saccharomyces cerevisiae , calcium alginate , yeast , calcium , fiber , ethanol , reaction rate , metal , nuclear chemistry , chromatography , catalysis , biochemistry , enzyme , organic chemistry
Saccharomyces cerevisiae (yeast) cells were employed as a source of alcohol dehydrogenase in the NAD + ‐to‐NADH reaction. The cells were immobilized in calcium alginate monofilament fibers and used in a biological reactor. The alginate could not be heat sterilized since temperatures above 80 °C caused the polymer chains to degrade. The same proved true for the high pH necessary for the reaction, but the alginate strength was increased by Ba 2+ solution treatment. X‐ray probe analysis showed that about 30% of the Ca 2+ sites exchanged with the Ba 2+ ions. The Ba 2+ ions (as well as the Ca 2+ ions) permeabilized the cells and increased the reaction rate. Long term trials showed that Ba 2+ ions were slowly elutriated from the fiber biocatalyst, causing a drop in reaction rate. The trend certainly was reversible as far as the fiber was concerned. It is assumed that the permeabilization of the cells by the Ba 2+ ions was a reversible process.