Catalyzes the interconversion of L-alanine and D-alanine. Is highly specific for alanine as substrate. May serve both anabolic and catabolic purposes. L-alanine = D-alanine Optimum pH is 8.0. Optimum temperature is 35 degrees Celsius. Amino-acid biosynthesis; D-alanine biosynthesis; D-alanine from L-alanine: step 1/1. Homodimer. Belongs to the alanine racemase family.