Effect of various growth media upon survival during storage of freeze-dried Enterococcus faecalis and Enterococcus durans.
OBJECTIVE
The effects of three different growth media (MRS, M17 and Lee's) on survival during freeze-drying and subsequent storage of six strains of Enterococcus faecalis and two strains of E. durans were investigated.


RESULTS
Distinct Enterococcus spp. strains were grown on M17, MRS and Lee's broth, freeze-dried and stored at 20 degrees C in air under darkness. At regular intervals throughout storage, freeze-dried samples were rehydrated and then plated on M17 agar.


CONCLUSIONS
A higher survival rate during storage of dried E. durans was obtained when growth occurred in MRS. The same effect was not observed, however, for the majority of E. faecalis strains, which clearly survived better in the dried state when this organism had been grown in M17 or Lee's medium.


CONCLUSIONS
The survival of the dried Enterococcus spp. tested during storage was shown to be strain-specific and dependent on the growth medium.
Carvalho
A S
AS
Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Porto, Portugal.
Silva
J
J
Ho
P
P
Teixeira
P
P
Malcata
F X
FX
Gibbs
P
P
D003470:Culture Media; D016983:Enterococcus / Q000502:physiology*; D013293:Enterococcus faecalis / Q000502:physiology; D005612:Freeze Drying; D011309:Preservation, Biological / Q000379:methods*; D011310:Preservatives, Pharmaceutical
D003470:Culture Media; D011310:Preservatives, Pharmaceutical