Xylitol is a mint flavored sweetener, produced naturally by plants and is found in fruits and vegetables. It is used as an ingredient in chewing gum, toothpaste, mouthwash and other products.
Badal Saha , a chemist at Agricultural Research Service (ARS) and collaborators have developed a genetically engineered bacteria, a modified form of Escherichia coli , which will be used to produce Xylitol on a large scale.
This research is being done through a cooperative agreement with zuChem, Inc., of Chicago, and the Biotechnology Research and Development Corporation in Peoria, Ill. ARS is the U.S. Department of Agriculture's chief scientific research agency.
Under the agreement, Saha is assisting zuChem to develop a commercial-scale process that could cut xylitol's production costs and enable its manufacture in the US from corn fibers and other crops.
Xylitol is used as a sugar substitute as it has one-third fewer calories, possesses a cool mint flavor, fights cavity-causing bacteria, and passes through the human gut without disturbing insulin.
Presently Xylitol is manufactured commercially from birch-wood fibers that are subjected to the combined action of acids, high pressure and temperature, chemical catalysts. The process involves a series of separation and purification steps. This process is expensive, and this xylitol has to be imported from Finland and China says Saha, at the ARS National Center for Agricultural Utilization Research in Peoria.
This study was done at the center's Fermentation Biotechnology Research Unit. In this study Saha and colleagues used an approach called metabolic pathway engineering to retool the enzyme-making machinery of E. coli bacteria so that they could convert two hemi cellulose sugars—xylose and arabinose—into xylitol.
The bacteria were then kept inside special biofermentors and fed on a "broth" of corn fibers and other hemi cellulose sources. The bacteria excreted xylitol that was later separated from the broth as a white, crystalline powder.