The nutrient medium may comprise carbon sources (e.g.
glucose, fructose, maltose, lactose, citric acid, fumaric acid),
nitrogen sources (e.g. corn steep liquor, yeast extract, pep
tone, polypeptone, casein hydrolysate, amino acid) and inor
ganic salts (e.g. sodium chloride, potassium phosphate, mag
nesium sulfate). Thus, the nutrient medium may be a conven
tional one employed for cultivation of bacteria. The addition
, of an amino acid such as asparagine or glutamine is particu
larly preferred for increasing the yield of asparaginase.