Recombinant GFP is produced in methanol-free cultivations of P. pastoris grown on either glycerol or glucose as the sole carbon source. GFP yield (mg L-1; green squares) was measured in the culture supernatant in all phases of two 1 L P. pastoris cultivations, one grown on glycerol (upper graph) and one grown on glucose (lower graph). The residual glycerol concentration (upper graph; g L-1; white triangles) was at its highest during phase I, eventually dropping to zero in phase II. The DCW (upper graph; g L-1; white circles) for this cultivation reached a maximum of 92.5 g L-1. The residual glucose concentration (lower graph; mM; white inverted triangles) eventually dropped to zero in phase II. The DCW (lower graph; g L-1; white circles) for this cultivation reached a maximum of 46.5 g L-1. All measurements were made in triplicate the error bars represent the SEM.