Figure 1.

Growth of M. mazei with different nitrogen availabilities. Cells were grown on 150 mM methanol in 5 ml of minimal medium in a nitrogen gas atmosphere containing 20% CO₂ (A), a hydrogen gas atmosphere containing 20% CO₂ (B), or an argon gas atmosphere containing 20% CO₂ (C). The medium was supplemented with 10 mM ammonium (◆) or contained no additional nitrogen source (■).