The induction of alcohol oxidase in methylotrophic yeasts.

Based on the large amount of alcohol oxidase that accumulates in methylotrophic yeasts upon growth on methanol, a micromethod was developed to determine the enzyme activity by modification of the method of Ellis et al. (1985). The amount of the enzyme in cell extracts of Pichia pastoris and Hansenula polimorpha was very high: 32% and 34% of the cellular protein respectively. Enzyme induction occurred as part of a more general physiological mechanism of response to methanol that includes other induced proteins and an increase in the size and number of peroxysomes. The induction process was also studied. Three necessary parameters to get a high yield of alcohol oxidase are the growing time in repressing conditions, the optical density at the moment of induction and the duration of induction.