FIG. 4.

Amino acid levels during biomass production. (A) Amino acid levels during 12 days of biomass cultivation. Graph shows consumption of five key amino acids being only partially replenished by media changes on days 5, 7, 9, and 11. (B) Successful maintenance of depleted amino acids during fermentation. Control was by use of a model relating cell proliferation and amino acid consumption to predict media supplementation; in all cases the minimum amino acid concentrations remained above 60% of initial value.