Physiology of the transformation process
Suitability of the cultivation medium
Results in Table 4 show that the composition of the
fermentation medium greatly affected GL convertibility.
Among tested media, medium I composed of (%, w/v):
GL, 1; glucose, 1; CSL, 0.8; pH 5.7 (Kuramoto et al. 1994)
was proved to be the best fermentation medium that
favored the hydrolysis of GL to GA and 3-oxo-GA (17.73,
7.4%, respectively). This was accompanied by the highest
total GL bioconversion estimate (25.19%). Good GL
bioconversion efficiency (16.2%) was achieved on
medium IV which is composed of (%, w/v): GL, 1; CSL,
0.8. These media (I & IV) were characterized by the
presence of GL as a carbon source and CSL as a sole
nitrogen source. Similar results have also been reported
by El-Menoufy (1988) who stated that, CSL could
successfully replace peptone and meat extract. Thus, the
superiority of medium I & IV may be due to the presence
of CSL which was not present in the other tested media.