ISOLATION OF MICROBODIES FROM SWEET-POTATO ROOT-TISSUE AND THEIR DEVELOPMENT DURING AGING OF SLICES

Microbodies were isolated from, sweet potato root tissue by differential and linear sucrose density gradient centrifugation. When the tissue was homogenized in the presence of Polyclar AT, the microbodies sedimented together with the mitochondria through the sucrose gradients. The microbodies had a density of 1.25 g/cm3, and contained catalase and urate oxidase, but not malate dehydrogenase, isocitrate lyase, glycolate oxidase, hydroxypyruvate reductase and the cyanide-insensitive palmitoyl CoA-oxidation system. A small amount of o-diphenol oxidase also seemed to be present.Catalase, but not urate oxidase, activity in the crude extract increased during aging of the sliced tissue. A similar result was obtained with the microbody fraction after linear sucrose density gradient centrifugation. We propose that microbodies containing only catalase develop during aging of sliced sweet potato root tissue. © 1979 Oxford University Press.