EFFECT OF MEDIUM COMPOSITION ON GROWTH AND ASPARAGINASE PRODUCTION OF VIBRIO-SUCCINOGENES

Asparaginase synthesis by V. succinogenes is induced by NH4+. 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 1/10 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. The levels of asparaginase accumulated within cells raise questions about the organism''s protein synthesizing system.