Characterization of peroxisomes in an n-alkane-utilizable yeast, Candida tropicalis, grown on glucose and propionate

Abstract

Two types of peroxisomes (microbodies) in different states of development, which are attractive for investigating the biogenesis of the organelles, were first isolated from the glucose- and propionate-grown cells of an n-alkane-utilizable yeast, Candida tropicalis pK 233, and their properties were disclosed. Peroxisomes isolated from the glucose-grown cells contained high levels of isocitrate lyase and malate synthase, whereas the levels of catalase and enzymes constituting the fatty acid β-oxidation system were demonstrated to be very low by means of subcellular fractionation and Western blot analysis. Citrate synthase common to the tricarboxylic acid and glyoxylate cycles was localized only in mitochondria. We have proposed that the peroxisomes in the glucose-grown cells are called ‘pro-peroxisomes’ or ‘prooxisomes’ to distinguish them from the ‘mature’ organelles in the alkane-grown cells which have high levels of catalase and the β-oxidation enzymes. The peroxisomes isolated from the propionate-grown cells exhibited higher levels of isocitrate lyase and malate synthase together with moderate levels of catalase and acyl-CoA oxidase inducibly synthesized in the cells. That is, the peroxisomes in the propionate-grown cells showed characteristics of both ‘prooxisomes’ and ‘mature’ peroxisomes, and were supposed to be an intermediate form deficient in some of the developmental processes.