Four enzymes which transferred amino group of l-alanine to α-keto acids were separated from Pseudomonas sp. and these enzymes were distinguished in substrate specificities from each other: the first is active on glyoxylate; the second, on straight-chain α-keto acids, e.g., α-ketobutyrate, α-ketovalerate and α-ketocaproate; the third, on various α-keto acids including α-ketoglutarate. The fourth is also active on various α-keto acids, however not active on α-ketogl utarate.