Figure 6.

Vanadate sensitive plasma membrane H⁺-ATPase in membrane fractions of Penicillium ochrochloron CBS 123.824 grown in chemostat culture with two limiting nutrients (glucose, G; ammonium, A). Plasma membranes (PM) were enriched from a homogenate (glass bead mill) using differential centrifugation yielding a microsomal fraction (MF) which was further subjected to partitioning in an aqueous polymer two phase system. Membranes from both phases of the two phase system (lower phase, intracellular membranes; ICM; upper phase, plasma membranes, PM) were collected and the total, as well as specific vanadate sensitive ATPase activity were determined. Membranes from the upper phase (PM) were also subjected to mass spectrometry and proteins quantified by the T3PQ method (normalized peak area). The values are the average of three (glucose limitation) or four (ammonium limitation) bioreactor runs.