We targeted xylitol and arabitol isomers as the value-added products to be produced from biodiesel glycerol**. Extensive culture screening of more than 300 strains in the USDA ARS culture collection (NRRL) was conducted to locate the best candidates. None of the strains were identified to produce xylitol as the dominant metabolite. Some were active producers of mixtures of polyols. Yet, several osmophilic yeasts produced arabitol as the dominant metabolite. The most promising yeast strain produced arabitol with more than 50% yield when grown on glycerol. This strain was subsequently studied for developing optimal production medium composition and culture conditions, including temperature, pH, dissolved oxygen concentration, nitrogen-to-phosphorus ratio, and glycerol concentration.

**Biodiesel produced from renewable oil sources is an attractive alternative fuel. Glycerol is a major byproduct from biodiesel production. Developing new industrial or commercial uses of biodiesel glycerol is imperative to the economic sustainability of the biodiesel industry.

 

 

 

Publications

Debaryomyces hansenii fermentation for arabitol production. (S. Koganti, L.-K. Ju) Biochemical Engineering Journal 79, 112– 119 (2013). Article

Purification of arabitol from fermentation broth of Debaryomyces hansenii using glycerol as substrate. (A. Al Loman and L.-K. Ju) Journal of Chemical Technology & Biotechnology 88, 1514–1522 (2013). Article

Production of arabitol from glycerol: strain screening and study of factors affecting production yield. (S. Koganti, T. M. Kuo, C. P. Kurtzman, N. Smith, and L.-K. Ju) Applied Microbiology and Biotechnology 90(1), 257-67 (2011). Artile