Preparation of L-threonine useful in animal nutrition, human medicine and pharmaceuticals industry, comprises continuously feeding to bacterial culture further nutrient medium comprising source(s) of carbon, nitrogen, and phosphorus

摘要

Preparation of L-threonine using Enterobacteriaceae comprises: (1) inoculating and culturing the bacterium in a first nutrient; (2) continuously feeding to culture further nutrient medium comprising source(s) of carbon, nitrogen and phosphorus under conditions to form L-threonine, and removing culture broth from culture; (3) removing the threonine; and (4) feeding back remaining culture broth to culture vessel. Preparation of L-threonine using Enterobacteriaceae comprises: (1) inoculating and culturing the bacterium in a first nutrient; (2) continuously feeding to culture in feed stream(s) a further nutrient medium comprising source(s) of carbon, nitrogen, and phosphorus under conditions to form L-threonine, and removing culture broth from culture with removal stream(s), which corresponds to the feed stream or the total of the feed streams; (3) completely or partly separating off the cells from the removal stream(s) with a return flow ratio R, (R=0-1) by appropriate processes and recycling into the culturing step; (4) removing the threonine formed directly from the removal stream(s) after complete or partial separating off of the cells from the removal stream(s); (5) feeding back remaining culture broth, remaining after removal of the threonine or with depleted biomass, to culture vessel; and (6) adjusting the concentration of the source of carbon during the culture to not > 30 g/l.