Screening of Alternative Carbon Sources for Recombinant Protein Production in Pichia pastoris

Abstract

Abstract Seventeen carbon sources were screened to identify those with the potential to support pGAP-regulated recombinant enzyme production by Pichia pastoris, using phytase as a model product. Of these, four, namely glucose, glycerol, fructose and ethanol, supported cell growth and enzyme production, and the performance of the latter two was analyzed. Ranges of acceptable residual carbon source concentrations, i.e. those at which no substrate-related growth inhibition occurred, were determined and used to design fed-batch bioreactor-based processes. In fed-batch cultures, fructose supported higher biomass concentrations and equivalent extracellular enzyme activities than glucose. The same metrics for the cultures grown on ethanol were comparable to those of the cultures grown on glucose, but with a greater required fermentation time.