Effect of nitrogen source
To investigate the effect of nitrogen sources on 5’-phosphodiesterase
production, conidia were inoculated into
the medium containing 6 % glucose and various nitrogen
sources including sodium nitrate, sodium nitrite, ammonium
sulphate, corn steep powder, urea, peptone and
yeast extract, where each nitrogen source was added to
the basal medium at fractions of 0.2 and 0.5 %. As shown
in Table 4, amongst 8 nitrogen sources examined, peptone
led to the highest 5’-phosphodiesterase activity of
227 U/mL.
Subsequently, the effect of peptone and corn steep
powder fractions (0–1.5 %) on 5’-phosphodiesterase production
was studied. The highest enzyme activity was
about 227 and 216 U/mL at peptone fraction of 0.2 %
and corn steep powder fraction of 0.5 %, respectively