L-Aspartate fermentation by a free-living Campylobacter species

In the fermentation of L-aspartate by a free-living Campylobacter spec., the products formed were acetate, succinate, carbon dioxide and ammonia. The oxidative part of the fermentation pathway yielded acetate, succinate, carbon dioxide and ammonia, and the reductive part gave rise to the formation of succinate and ammonia. When grown anaerobically with aspartate, cells contained cytochromes b and c as well as menaquinone. Reduced cytochrome b, but not reduced cytochrome c could be reoxidized by fumarate. In the presence of nitrate, 90% of the available electrons were transferred to nitrate, which was reduced to nitrite; the remainder was transported via the fumarate reductase system. Cells grown with aspartate and excess of formate converted aspartate quantitatively to succinate.