Fermentative production of mannitol

1. An improved process for continuous fed-batch fermentative production of mannitol, the process comprising culturing a microorganism capable of producing mannitol in a fermentation broth under conditions suitable to produce mannitol, the improvement comprising a fermentation broth having corn steep liquor as a complex nitrogen source and about 0.2 ml/L to about 1 ml/L protease.

2. The improved process of claim 1 , wherein the fermentation broth comprises about 0.01 g/L to about 0.2 g/L tryptophan.

3. The improved process of claim 1 , wherein the fermentation broth comprises about 0.5 g/L to about 20 g/L casein hydrolysate.

4. The improved process of claim 1 , wherein the fermentation broth comprises about 0.5 g/L to about 20 g/L casein hydrolysate and about 0.01 g/L and about 0.2 g/L tryptophan.

5. The improved process of claim 1 , wherein the fermentation broth comprises about 0.01 g/L to about 0.2 g/L tryptophan, about 0.01 g/L to about 0.2 g/L tyrosine, and about 0.01 g/L to about 0.2 g/L aspartic acid.

6. The improved process of claim 1 , wherein the pH of the fermentation broth is about 5.0 to about 6.0 during fermentation.

7. The improved process of claim 1 , wherein production of mannitol is greater than about 150 g/L.

8. The improved process of claim 1 , wherein the rate of production of mannitol is greater than about 6 g/L-h.

9. The improved process of claim 1 , wherein the microorganism is Lactobacillus intermedius, Leuconostoc mesenteroides subsp. dextranicum, Lactobacillus cellobiosus, Leuconostoc paramesenteroides, Lactobacillus fermentum, Lactobacillus buchneri, Leuconostoc amelibiosum, Lactobacillus brevis, Lactobacillus citrovorum or a combination thereof.

10. The improved process of claim 1 , wherein the pH during the continuous fed-batch fermentative production is controlled with NH 4 OH, NaOH, gaseous NH 3 , CaCO 3 , or a combination thereof.

11. The improved process of claim 1 , wherein the process further comprises clearing the fermentation broth by centrifugation, filtration or hollow fiber filtration.

12. The improved process of claim 1 , wherein the process further comprises clearing the fermentation both by filtration, wherein the filtration comprises adding CaCO 3 to the fermentation broth and lowering the pH with sulfuric acid and filtering the fermentation broth.

13. The improved process of claim 1 , wherein the process further comprises concentrating the fermentation broth to about 30% to 36% mannitol by batch evaporation or continuous flow evaporation.

14. The improved process of claim 13 , wherein the process further comprises crystallizing the concentrated fermentation broth.

15. The improved process of claim 1 , wherein the fermentation broth comprises about 64 g/L initial volume to about 120 g/L initial volume of corn steep liquor.

16. An improved process for continuous recycle fermentative production of mannitol, the process comprising culturing a microorganism capable of producing mannitol in a fermentation broth under conditions suitable to produce mannitol, the improvement comprising using fermentation broth having corn steep liquor as a complex nitrogen source and about 0.2 ml/L to about 1 ml/L protease.

17. The improved process of claim 16 , wherein the fermentation broth comprises about 0.01 g/L to about 0.2 g/L tryptophan.

18. The improved process of claim 16 , wherein the fermentation broth comprises about 0.5 g/L to about 20 g/L casein hydrolysate.

19. The improved process of claim 16 , wherein the fermentation broth comprises about 0.5 g/L to about 20 g/L casein hydrolysate and about 0.01 g/L and about 0.2 g/L tryptophan.

20. The improved process of claim 16 , wherein the fermentation broth comprises about 0.01 g/L to about 0.2 g/L tryptophan, about 0.01 g/L to about 0.2 g/L tyrosine, and about 0.01 g/L to about 0.2 g/L aspartic acid.

21. The improved process of claim 16 , wherein the pH of the fermentation broth is about 5.0 to about 6.0 during fermentation.

22. The improved process of claim 16 , wherein a dilution range is about 0.1 to about 0.55 vol/h.

23. The improved process of claim 16 , wherein the rate of production of mannitol is greater than about 30 g/L-h.

24. The improved process of claim 16 , wherein the microorganism is Lactobacillus intermedius, Leuconostoc mesenteroides subsp. dextranicum, Lactobacillus cellobiosus, Leuconostoc paramesenteroides, Lactobacillus fermentum, Lactobacillus buchneri, Leuconostoc amelibiosum, Lactobacillus brevis, Lactobacillus citrovorum or a combination thereof.

25. The improved process of claim 16 , wherein the pH during the continuous fed-batch fermentative production is controlled with NH 4 OH, NaGH, gaseous NH 3 , CaCO 3 , or a combination thereof.

26. The improved process of claim 16 , wherein the process further comprises clearing the fermentation broth by centrifugation, filtration or hollow fiber filtration.

27. The improved process of claim 16 , wherein the process further comprises clearing the fermentation broth by filtration, wherein the filtration comprises adding CaCO 3 to the fermentation broth and lowering the pH with sulfuric acid and filtering the fermentation broth.

28. The improved process of claim 16 , when the process further comprises concentrating the fermentation broth to about 30% to 36% mannitol by batch evaporation or continuous flow evaporation.

29. The improved process of claim 28 , wherein the process further comprises crystallizing the concentrated fermentation broth.

30. The improved process of claim 16 , wherein the fermentation broth comprises about 9% to about 15% fructose and from about 2% to about 10% glucose.

31. The improved process of claim 16 , wherein the fermentation broth comprises about 10 to about 40 g/L corn steep liquor.