Summary
The
shelf-life of a culture medium is the maximum period of validity
for optimum preparation and preservation. Apart from the composition
of the medium, the factors that influence shelf-life are sterilisation
method, preservation and packaging procedures, storage temperature
and exposure to light. The shelf-life of a culture medium is defined
by evaluating its basic chemico-physical characteristics so as to
obtain the correct growth and characterisation of a specific microorganism.
This research was conducted from March to September 2003 on 12 critical
culture media, i.e. media that had a coded shelf-life of not more
than thirty days. Each medium was produced in three separate batches,
with a total of 5 940 samples. The purpose of the study was
to define a longer period of validity than that coded for each medium
by evaluating weight reduction, pH, fertility and sterility. The
shelf-life observed for each medium was longer than those coded.
The new shelf-life takes into account both the operational needs
of complex organisational structures and the efficiency of the medium,
depending on its chemico-physical characteristics and storage and
preservation methods.
Keywords
Culture
media, Ecometric techniques, Quality control, Shelf-life. |