Abstract
Cells of Saccharomyces carlsbergensis H 60 synthesize alcohol dehydrogenase (ADH) in media containing 2% lactat, 1% ethanol or 0.1% glucose. Crystals may be induced in protoplasts of these cells. Increase of glucose concentration in the medium results in diminished ADH synthesis and decreased tendency for crystal formation. Repression of ADH synthesis by glucose results in the formation of a protein (MG 110000 D), the significance of which is discussed. Early stages of crystal formation inside the cell are demonstrated electronmicroscopically. At first dense material accumulates between opposite membranes of neighbouring mitochondria. Within mitochondria frequently membrane bundles occur in close vicinity to crystals. These ADH-crystals arise from this material.