Effect of medium composition on the growth and asparaginase production of Vibrio succinogenes.

Asparaginase synthesis by Vibrio succinogenes is induced by ammonium ions. Synthesis occurs throughout exponential phase, and in early stationary phase asparaginase accounts for about 5% of the total soluble protein. The organism grows best when fumarate is provided as the terminal electron acceptor of the formate-oxidizing cytochrome system. Yeast extract or enzyme-hydrolyzed proteins are effective nutrient sources. In an ammonium formate-sodium fumarate medium, where maximum growth and asparaginase synthesis occurs, the total enzyme yield (international units per liter of culture) is about one-tenth that obtainable with a good asparaginase-producing strain of Escherichia coli. The energetic inefficiency of V. succinogenes appears to cause a low yield of cells and therefore low total enzyme yield. However, the levels of asparaginase accumulated within cells raise questions about the organism's protein synthesizing system.