The Terminal Respiratory Enzymes in Neurospora Tetrasperma

Open Access
Publisher Website
Google Scholar
Abstract
The terminal oxidase system in cell-free extracts of N. tetrasperma consisted of essentially the cytochrome system. The presence of cytochrome oxidase, succinic dehydro-genase, and succinic oxidase was confirmed. The presence of diphosphopyridine and triphosphopyridine nucleotide linked cytochrome c reductases were demonstrated. Glycolic acid oxidase was not found but glycolic acid dehydrogenase was. Laccase and ascorbic acid oxidase were not detected. With a high speed centrifugation (16,000 x g), cytochrome oxidase was found in the particulate fraction while catalase and peroxidase were in the corresponding supernatant fraction. In ascospore homogenates, the presence of cytochrome oxidase, catalase and peroxidase were demonstrated. Mycelial respiration was inhibited by cyanide using the Warburg indirect method of manometry. A small residual cyanide respiration was always obtained by direct manometry.