“…Besides LDH and LOX, another enzyme is known for participating in the lactic acid metabolism in yeasts, namely L-lactate-cytochrome c oxidoreductase (EC 1.1.2.3; flavocytochrome b 2 , FC b 2 ) (Brooks, 2002), which catalyses the electron transfer from L-lactate to cytochrome c in yeast mitochondria. The protein can be isolated from Saccharomyces cerevisiae and Hansenula anomala (Labeyrie et al, 1978;Haumont et al, 1987;Silvestrini et al, 1993) as a tetramer with four identical subunits, each consisting of FMN-and heme-binding domains. FC b 2 has absolute specificity for L-lactate, moreover, it functions in vitro without regard to the nature of electron acceptors which makes this enzyme very promising for analytical biotechnology.…”