Maruyama, Yoshiharu (Cornell University, Ithaca, N.Y.) and Martin Alexander. Localization of enzymes in the mycelium and microconidia of Fusarium oxysporum. J. Bacteriol. 84:307-312. 1962-Extracts prepared from mycelium and microconidia of Fusarium oxysporum f. cubense were fractionated into a soluble and four particulate fractions by differential centrifugation, and the distribution of several enzymes in the isolated cell constituents was examined. Succinic dehydrogenase, cytochrome oxidase, and a large amount of the reduced diphosphopyridine nucleotide (DPNH) cytochrome c reductase and reduced triphosphopyridine nucleotide cytochrome c reductase were associated with one of the particulate fractions prepared from the hyphae; fumarase and DPNH oxidase activities were largely found in the soluble and in a second particulate fraction. The highest recovery and concentration of diphosphopyridine nucleotidase was observed to be bound to a third type of hyphal granule. Aldolase, aconitase, glucose-6-phosphatase, and uricase were recovered entirely with the soluble mycelium constituents. Similar enzyme-distribution patterns were observed in microconidia. Several enzymatic activities of the mycelial extracts were compared with those in the extracts of microconidia.