Catalyzes the reversible reductive amination of pyruvate to L-alanine (Probable). A key factor in the assimilation of L-alanine as an energy source via the tricarboxylic acid cycle during sporulation (By similarity). H2O + L-alanine + NAD(+) = H(+) + NADH + NH4(+) + pyruvate Retains about 50% of its initial activity when heated at 85 degrees Celsius for 5 min at pH 7.2. Amino-acid degradation; L-alanine degradation via dehydrogenase pathway; NH(3) and pyruvate from L-alanine: step 1/1. Homohexamer. Belongs to the AlaDH/PNT family.