Properties and function of fumarate reductase (NADH) in Streptococcus lactis

The fumarate reductase (NADH) present in cell-free extracts of S. lactis C10 was purified approximately 100-fed by chromatography on DEAE-cellulose in the presence of the non-ionic detergent Teric X-10, and some of the properties of this partially purified enzyme were characterized. Fumarate was able to act as a terminal electron acceptor and decreased the amount of lactate formed and oxygen used during the metabolism of pyruvate by resting cells of S. lactis. Anaerobic growth of S. lactis on glycerol was not observed and fumarate reduction was not coupled with glycerol-3-phosphate oxidation.