3.3. Effect of nitrogen sources, C/N ratio, and initial sugar
concentration on cell growth and PHB production
Nitrogen source is an important factor for the accumulation of
PHB. Under the conditions of nitrogen limitation (0.89 g/L (NH4)2-
SO4 in MSM medium), the PHB content reached 53% in B. megaterium
R11 even though its CDW was only 2–2.5 g/L (Fig. 2B). In
this part of the study, two inorganic and three organic nitrogen
sources were tested at 6 g/L. As shown in Table 1, apparently
tryptone was the best nitrogen source for strain R11 by presenting
the highest CDW (6.31 g/L), almost three times that in nitrogen