ASSESMENT OF CRYOPRESERVATION SYSTEMS INFLUENCE ON THE SURVAVIAL OF E. COLI RECOMBINANT STRAINS
Keywords:
cryopreservation system, recombinant bacteria survival, bacteria cultureAbstract
The cryopreservation systems of recombinant bacterial cells based on glycerol were
studied in these experiments according to the hypothesis that glycerol is one of the
widely used cryoprotective additives in microbiology and a multitude of factors
affecting the effectiveness of cryopreservation in microorganisms; the best
cryoprotective additive and the optimum concentration for a particular
microorganism has to be determined empirically. The results obtained in this
experiment are showing that the freezing procedure at -80°C in LB 40% glycerol is
the optimum system for the cryopreservation of E. coli DH5α recombinant cells. The
use of SOC medium supplemented with 10g/l NaCl provided more proper conditions
of culture for the defrosted E. coli DH5α recombinant cells, reducing the osmotic
stress during the recovery after thawing. The utilization of this optimum
cryopreservation system offer the possibility of preserving the large volume of work
and time involved by the recombinant DNA technology procedures applied for
obtaining a recombinant strain, avoiding the storage of recombinant strains by
costly and time consuming microbiology culturing techniques.
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