Mitochondrial NAD, L-lactate dehydrogenase and NAD, D-lactate dehydrogenase in the yeast Saccharomyces cerevisiae.

Mitochondrial NAD-linked L- and D-lactate dehydrogenase activities have been found in the yeast Saccharomyces cerevisiae grown at high (3%) but were absent at low (0.6%) glucose concentrations. The inhibition of mitochondrial protein synthesis by chloramphenicol and of primary respiration by antimycin A determines the appearance of the two activities even at low (0.6%) glucose concentration. Two respiratory deficient strains belonging respectively to the mit- class (which maintains mitochondrial protein synthesis) and to the rho- class (which loses mitochondrial protein synthesis) display the activities even at low (0.6%) glucose concentration. L- and D-lactate have been detected in the growth medium when the cultures had been undertaken at high glucose concentrations, but were absent at low glucose concentrations.