Effect of solute and matric potential on growth rate of fungal species isolated from cheese

Resumen

The effect of water potential (
J
w
) on the growth of 15 fungal species isolated from cheeses was analysed.
The species, identified mainly by analysis of DNA sequences, belonged to genera
Penicillium
,
Geotrichum
,
Mucor
,
Aspergillus
,
Microascus
and
Talaromyces
. Particularly, the effect of matric potential (
J
m
), and ionic
(NaCl) and non-ionic (glycerol) solute potentials (
J
s
) on growth rate was studied. The response of strains
was highly dependent on the type of
J
w
. For
J
s
, clear profiles for optimal, permissive and marginal
conditions for growth were obtained, and differences in growth rate were achieved comparing NaCl and
glycerol for most of the species. Conversely, a sustained growth was obtained for
J
m
in all the strains,
with the exception of
Aspergillus pseudoglaucus
, whose growth increased proportionally to the level of
water stress. Our results might help to understand the impact of environmental factors on the
ecophysiology and dynamics of fungal populations associated to cheeses.