Characterization of <i>Neurospora crassa</i> Mitochondria Prepared with a Grind‐Mill

Abstract

Mitochondria can be isolated rapidly from Neurospora crassa with high yields by disrupting the hyphae suspension between the two grinding wheels of a simple mill. The isolated mitochondria respire with pyruvate + malate, succinate, and with NADH and NADPH in high rates and well coupled to oxidative phosphorylation. Three phosphorylation steps are involved in the oxidation of pyruvate and two in the oxidation of succinate, NADH and NADPH. Rotenone, antimycin and KCN inhibit the electron flow at the known steps. The cytochrome composition pattern is characterized by a particularly high content of cytochrome c . Evidence is given for the existence of two NADH‐dehydrogenases for the oxidation of exogenous and endogenous NADH with different localizations on the inner mitochondrial membrane. On the basis of these properties, mitochondria from Neurospora crassa can be looked upon in analogy to mitochondria from yeast, particularly from Torulopsis utilis .