Lactic acid racemase and

Stetter, K. O. and Handler, 0.1973. Formation of DL-lactic acid by lactobacilli and characterization of a lactic acid racemase from severed streptobacteria. Arch. Mikrobiol. 94, 221-247. 

Since the discovery of enzymatic racemization of lactate by lactic acid bacteria11, 2 Clostridium acetobutyricum, and Cl. butyricum[4 a variety of racemases and epimerases have been demonstrated, and they are classified into the four groups as follows ... 

Fermentation of glucose, glycerol, and lactic acid by propionibacteria utilizing the succinate-propionate pathway. 1 (S)-methylmalonyl-CoA-pyruvate transcarboxylase, 2 malate dehydrogenase 3 fumarase, 4 fumarate reductase, 5 CoA transferase, 6 (R)-methylmalonyl-CoA mutase, and 7 methylmalonyl-CoA racemase... 

M. Yohda, H. Okada and H. Kumagai, "Molecular cloning and nucleotide sequencing of the aspartate racemase gene from lactic acid bacteria Streptococcus thermophilus", Biochimica et Biophysica Acta 1089,234-240 (1991). 

---