Catalyzes the stereospecific oxidation of D-lactate to pyruvate. Involved in the detoxification of methylglyoxal and D-lactate, but probably not involved in the metabolization of glycolate. (R)-lactate + 2 Fe(III)-[cytochrome c] = 2 Fe(II)-[cytochrome c] + 2 H(+) + pyruvate Binds 1 FAD per monomer. Inhibited by cyanide ions. kcat is 88 min(-1) with D-2-hydroxybutyrate as substrate (with cytochrome c as acceptor molecule) (PubMed:19586914). kcat is 65 min(-1) with D-lactate as substrate (with cytochrome c as acceptor molecule) (PubMed:19586914). kcat is 7 min(-1) with L-lactate as substrate (with cytochrome c as acceptor molecule) (PubMed:19586914). kcat is 6 min(-1) with D-glycerate as substrate (with cytochrome c as acceptor molecule) (PubMed:19586914). kcat is 0.1 min(-1) with glycolate as substrate (with cytochrome c as acceptor molecule) (PubMed:19586914). kcat is 73 min(-1) with D-lactate as substrate (with DCIP as acceptor molecule) (PubMed:19586914). kcat is 5 min(-1) with L-lactate as substrate (with DCIP as acceptor molecule) (PubMed:19586914). kcat is 0.4 min(-1) with glycolate as substrate (with DCIP as acceptor molecule) (PubMed:19586914). Optimum pH is 8-9. Homodimer. Expressed in leaves, stems, flowers and roots. By light. No visible phenotype when grown under standard conditions, but developmental retardation and lethality when grown in presence of methylglyoxal or D-lactate. Belongs to the FAD-binding oxidoreductase/transferase type 4 family.