Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 16, 2006
Publication Date: July 1, 2006
Citation: Saha, B.C. 2006. Effect of salt nutrients on mannitol production by Lactobacillus intermedius NRRL B-3693. Journal of Industrial Microbiology and Biotechnology. 33(10):887-890. Interpretive Summary: Mannitol, a naturally occurring alcohol, is widely used in the food, pharmaceutical, medicine, and chemical industries. It is currently produced as a 25/75 mixture of mannitol and sorbitol (another sugar alcohol) by high pressure hydrogenation of 50/50 fructose/glucose mixture (corn derived sugars) in an aqueous solution at high temperature with a catalyst. The chemical process is inefficient. One lactic acid bacterium from the ARS Culture Collection (Peoria, IL) was found to be an excellent producer of mannitol from fructose. Lactic acid bacteria are generally known to require four salt nutrients. This particular bacterium was found to require only one salt nutrient (manganese sulfate). This will help to reduce the medium cost for industrial production of mannitol.
Technical Abstract: The effects of four salt nutrients (ammonium citrate, sodium phosphate, magnesium sulfate, and manganese sulfate) on the production of mannitol by Lactobacillus intermedius NRRL B-3693 in a simplified medium containing 300 g fructose, 5 g soy peptone, and 50 g corn steep liquor per L in pH-controlled fermentation at 5.0 at 37 deg C were evaluated using a fractional factorial design. Only manganese sulfate was found to be essential for mannitol production. A manganese sulfate concentration of 33 mg/L was found to be optimal for the fermentation. The bacterium produced 200.6 ± 0.2 g mannitol, 61.9 ± 0.1 g lactic acid, and 40.4 ± 0.3 g acetic acid from 300 g fructose per L in 67 h.