Figure 3

Aerobic batch cultivation of K. marxianus DSM 5422 in stirred bioreactors using ammonium or urea. Aerobic batch cultivation of K. marxianus DSM 5422 in a stirred bioreactor using ammonium (white symbols) or urea (grey symbols) as a source of nitrogen. DW medium with 2 mL/L trace-element solution was supplemented with (NH₄)₂SO₄ or urea plus Na₂SO₄ (white symbols = 10 g/L (NH₄)₂SO₄; grey symbols = 5 g/L urea and 0.4 g/L Na₂SO₄); the cultivation occurred in an 1-L stirred reactor at 1,200 rpm, 32°C, and aeration with 50 L/h; the pH was controlled to ≥5 with 2 M KOH; the given growth rate was derived from measured CO₂ data.