INVERTASE SECRETION IN HANSENULA-POLYMORPHA UNDER THE AOX1 PROMOTER FROM PICHIA-PASTORIS

A DNA fragment containing a transcription regulating region of the alc ohol oxidase (AOX1) gene from the methylotrophic yeast Pichia pastoris was used in the construction of a vector for the expression of hetero logous proteins in the methylotrophic yeast Hansenula polymorpha. We u sed this vector to clone the SUC2 gene from Saccharomyces cerevisiae i nto H. polymorpha yeast. The culture conditions for invertase producti on using a fed-batch culture were studied. More than 1.5 x 10(3) U/ml of biologically active invertase (1 g/l) were secreted to the cellular periplasmic space. The fermentative process was scaled up to 501. Inv ertase produced from H. polymorpha was glycosylated, but it contained significantly less carbohydrate than protein produced by S. cerevisiae . Using the Western-blot technique, it was observed that invertase sec reted from H. polymorpha and invertase secreted from S. cerevisiae sho wed common antigenic determinants.