Figure 2. Effect of sodium nitrate concentration in Dubos salt medium on FPase (ο), cell mass (Δ) and extracellular protein (ٱ) production following growth on alpha-cellulose. The initial pH of the medium was 7.3, inoculum size 10%, on 1% (w/v) substrate, and temperature 30ºC. Error bars show standard deviation among three replicates.