Microbodies and glyoxylate-cycle enzyme activities in filamentous fungi

Abstract

Microbodies were observed in the hyphal tips of all 14 fungi investigated. Their morphology varied among the fungi and their numbers were influenced by the growth medium. Microbodies were closely associated with mitochondria in one fungus and with the endoplasmic reticulum in several fungi. Catalase was not detected in microbodies with the diaminobenzidine cytochemical procedure even though catalase activity was present in extracts of these fungi. The activities of the glyoxylate-cycle enzymes isocitrate lyase and malate synthase were affected by the growth medium and were particulate in the two fungi studied by differential centrifugation. Microbodies are abundant, and they are ubiquitous among the fungi and in some cases they may contain glyoxylate-cycle enzymes.