The biomass yield primarily depends on the strain’s features,
e.g. the ability to assimilate various carbon and nitrogen sources.
Three strains (T. cutaneum, P. stipitis and S. cerevisiae) were able
to assimilate the ammonium ion and urea as a nitrogen source,
so the biomass concentration after cultivations with different
nitrogen sources varied in a narrow range, e.g. 8.9–
9.2 g DM dm3 for S. cerevisiae and 10.5–11.4 g DM dm3 for T.
cutaneum. For C. guilliermondii, which is not able to assimilate urea,
the biomass varied from 6.3(±0.22) g DM dm3 (with only urea as
the N source) to 10.3(±0.45) g DM dm3 (with only ammonium
ions as the N source). A similar differentiation was observed for
the second strain that was not able to hydrolyse urea, i.e. C. tropicalis.
The biomass concentration depended on specific cultivation
conditions (e.g. time, temperature, pH) and medium content,