M. Dominguez et al., Optimization of bagasse, nutrients and initial moisture ratios on the yield of penicillin in solid-state fermentation, WORLD J MIC, 17(7), 2001, pp. 751-756
An advanced solid-state fermentation (SSF) system (liquid medium absorbed o
n an inert support) has been applied to antibiotic production. The main com
ponents of this solid medium are: support (sugarcane bagasse), nutrients an
d water. The first two are solids and have to be considered to calculate th
e initial moisture content (IMC) of the medium. Earlier work indicated the
importance of using high IMCs and concentrated media to obtain high penicil
lin yields in SSF. Nevertheless, the present work shows that high values of
IMC or nutrients content can stimulate or inhibit penicillin production, d
epending on the strategy used to compensate this change (i.e. the proportio
ns of the other two components). Conversely, increasing bagasse content alw
ays showed an inhibitory effect on the production. Since penicillin product
ion depends on the combinations of these components, a global approach was
used. The effect of the proportions of the three components on penicillin p
roduction was studied by means of a triangle of combinations and a 3D graph
. It was possible to establish that high penicillin production is only obta
ined in a zone of low support content (10-12.5%). Surprisingly, one product
ion maximum was observed in a zone of low moisture and high nutrients conte
nt (62 and 25.5% respectively); and another one in a zone of high moisture
and a relatively low nutrients concentration (75.5 and 12.4% respectively).