Figure 4

Aerobic batch cultivation of K. marxianus DSM 5422 in stirred bioreactors using (NH ₄ ) ₂ SO ₄ and NH ₄ OH. Aerobic batch cultivation of K. marxianus DSM 5422 in a stirred bioreactor using various amounts of (NH₄)₂SO₄ and NH₄OH as sources of nitrogen. DW medium with 2 mL/L trace-element solution was supplemented with (NH₄)₂SO₄ or Na₂SO₄ (white symbols = 0.4 g/L Na₂SO₄; grey symbols = 1 g/L (NH₄)₂SO₄; black symbols = 2 g/L (NH₄)₂SO₄); 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 NH₄OH; the given growth rates were derived from measured CO₂ data.