In the reference cultures the addition of a methanol pulse was followed by an immediate drop of the pO 2 level. However, within 5 to 10 h after a methanol pulse the pO 2 raised, indicating exhaustion of the substrate (methanol). The pO 2 dropped to zero only when the shaker was Schematic presentation of the wireless data collection and control system for shake flask cultivations Figure 2 Schematic presentation of the wireless data collection and control system for shake flask cultivations.