FERMENTATION PROCESS DEVELOPMENT FOR MANNITOL PRODUCTION BY A HETEROFERMENTATIVE LACTIC ACID BACTERIUM

Authors: Saha, Badal; RACINE, MICHAEL - ZUCHEM

Submitted to: Symposium on Lactic Acid Bacteria Genetics Metabolism and Applications
Publication Type: Abstract Only
Publication Acceptance Date: 9/1/2005
Publication Date: 9/1/2005
Citation: Saha, B.C., Racine, M. 2005. Fermentation process development for mannitol production by a heterofermentative lactic acid bacterium [abstract]. Symposium on Lactic Acid Bacteria Genetics Metabolism and Applications. Paper No. A036.

Interpretive Summary:

Technical Abstract: Mannitol (U.S. $3.32 per pound), a naturally occurring polyol, is widely used in the food, pharmaceutical, medicine, and chemical industry. The production of mannitol by fermentation has become attractive because of the problems associated with its production chemically. We have found that Lactobacillus intermedius NRRL B-3693 is a rapid and efficient producer of mannitol from fructose after screening 72 bacterial cultures from the ARS Culture Collection. The heterofermentative bacterium produces lactic acid (0.20 g/g) and acetic acid (0.10 g/g) in addition to mannitol (0.70 g/g). One-third of fructose can be replaced by glucose and other carbon sources. Mannitol at or above 180 g/L crystallizes out from the fermentation broth by cooling at 4 deg C. Therefore, we have investigated whether an industrial fermentation process could be developed with this strain that would be economically competitive with the chemical hydrogenation process currently used. In this presentation, our research dealing with the optimization of medium components and fermentation conditions for production of mannitol by this lactic acid bacterium using pH-controlled batch and fed-batch fermentations and cheap carbon and nitrogen sources will be described. The problems and prospects of cost-effective mannitol production by fermentation and future directions of research will be highlighted.