HANCOCKS, N.H. ... et al, 2010. An investigation into the preservation of microbial cell banks for alpha-amylase production during 5L fed-batch Bacillus licheniformis fermentations. Biotechnology Letters, 32 (10), pp. 1405-1412.
Fluorescent staining techniques were used
for a systematic examination of methods used to cryopreserve microbial cell banks. The aim of
cryopreservation here is to ensure subsequent reproducible
fermentation performance rather than just
post thaw viability. Bacillus licheniformis cell physiology
post-thaw is dependent on the cryopreservant
(either Tween 80, glycerol or dimethyl sulphoxide)
and whilst this had a profound effect on the length
of the lag phase, during subsequent 5 l fed-batch
fermentations, it had little effect on maximum
specific growth rate, final biomass concentration or
a-amylase activity. Tween 80 not only protected the
cells during freezing but also helped them recover
post-thaw resulting in shorter process times.
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