PROMITOCHONDRIA OF ANAEROBICALLY GROWN YEAST .3. MORPHOLOGY

Electron micrographs of frozen-etched, anaerobically grown Saccharomyces cerevisiae cells reveal the presence of mitochondria-like structures. These nonrespiring “promitochondria” resemble aerobic yeast mitochondria with respect to their characteristic cristae, their double-layered envelope, and their brittle outer membrane which exhibits slits of approximately 100 × 1000 Å. Promitochondria were found regardless of whether the cells had been grown in the presence or the absence of Tween 80 and ergosterol. These observations support the view that anaerobically grown S. cerevisiae still contains mitochondrial structures. © 1969, American Chemical Society. All rights reserved.