Narrative: Enzymes are proteins contained within cells that serve as biological catalysts of specific biochemical reactions. Production of a myriad of enzymes for both analytical, diagnostic, or therapeutic uses is a major concern of the biochemical industry. Enzymes are produced by cultivating microorganisms under optimum growth conditions, collecting the microbe, and extracting and purifying the desired protein. Currently, two classes of enzymes, alcohol- and glucose-oxidizing enzymes, are produced commercially using the yeast, Hansenula polymorpha, grown in continuous culture using a single carbon energy substrate; either methanol or glucose. Results of past work indicate levels of both enzymes can be doubled or tripled if a mixture of glucose and methanol is used at low growth rate. This research intends to extend the above steady-state work to investigate effects of prescribed shifts in both system growth rate and substrate carbon mixtures on enzymes productivity. Results will increase our understanding of microbial regulatory processes under transient conditions.
