Whey fermentation by Anaerobiospirillum succiniciproducens for production of a succinate-based animal feed additive

Anaerobic fermentation processes for the production of a succinate-rich ani mal feed supplement from raw whey were investigated with batch, continuous, and variable-volume fed-batch cultures with Anaerobiospirillum succinicipr oducens. The highest succinate yield, 90%, was obtained in a variable-volum e fed-batch process in comparison to 80% yield in a batch cultivation mode. In continuous culture, succinate productivity was 3 g/liter/h, and the yie ld was 60%. Under conditions of excess CO2, more than 90% of the whey-lacto se tvas consumed, with an end product ratio of 4 succinate to 1 acetate, Un der conditions of limited CO2, lactose was only partially consumed and lact ate was the major end product, with lower levels of ethanol, succinate, and acetate, When the succinic acid in this fermentation product was added to rumen fluid, it was completely consumed by a mixed rumen population and was 90% decarboxylated to propionate on a molar basis. The whey fermentation p roduct formed under excess CO2, which contained mainly organic acids and ce lls, could potentially be used as an animal feed supplement.