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Estimation of the disruption in freeze‐pressed Accharomyces cerevisiae by an electronic particle counter
Author(s) -
Magnusson KarlEric,
Edebo Lars
Publication year - 1974
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.260160910
Subject(s) - particle counter , electrical resistivity and conductivity , particle (ecology) , yeast , materials science , chemistry , biophysics , analytical chemistry (journal) , chromatography , physics , biology , biochemistry , ecology , aerosol , organic chemistry , quantum mechanics
An electronic particle counter has been used to estimate the disintegration by freeze‐pressing baker's yeast. A counter threshold level which just yielded the maximum count for intact cells was selected. The conductivity of the suspending medium was chosen such that maximum counts were obtained. Under these conditions, the electronic counts agreed well with the visual counts. At a certain threshold level the maximum count was obtained at a lower resistivity (higher conductivity) in the suspending solution with the freeze‐pressed suspension than with untreated cells, indicating that damage to the permeability barrier may occur without disruntion of the cell envelope. Fresh baker's yeast cells do not behave as nonconducting particles. This has to be taken into account when volume determinations with electronic particle counters are performed.