Submitted to: Journal of Industrial Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 21, 2002
Publication Date: October 1, 2002
Citation: LEATHERS, T.D., NUNNALLY, M.S., COTE, G.L. MODIFICATION OF ALTERNAN BY NOVEL PENICILLIUM SPP. JOURNAL OF INDUSTRIAL MICROBIOLOGY AND BIOTECHNOLOGY. 2002. V. 29. P. 177-180. Interpretive Summary: Domestic replacements are needed for certain imported commodities, particularly to improve the U.S. balance of trade. At the same time, new value-added markets are needed for American farmers. Gum arabic is important in food processing and has other industrial applications. The United States imports about 25 million pounds of gum arabic per year from the Middle East and mainly from Sudan. This represents a market of tens of millions of dollars annually, a significant fraction of the U.S. gum market. In addition, imported materials are available only at unreliable supply, quality, and price. Microbial gums are potential substitutes for gum arabic but require expensive processing to simulate some of the important functional properties. We discovered a novel bioconversion process that modifies a natural microbial gum such that it better mimics gum arabic. Furthermore, this gum is produced from cane or beet sugar, providing a potential new value-added market for U.S. sugar producers. This work will be of interest to researchers, sugar producers, and food industry processors.
Technical Abstract: Four strains identified as Penicillium spp. were isolated from soil samples based on their capacity to modify the unique polysaccharide, alternan. Spores from these isolates germinated in medium containing alternan and reduced the apparent molecular weight of alternan as determined by high pressure size exclusion chromatography and viscometry. However, the fungi exhibited limited growth on alternan and did not consume the substrate. The rheological properties of the modified alternan resembled those of commercial gum arabic. Thus, treatment of native alternan with spores from these Penicillium spp. strains constitutes a simple bioconversion method to quantitatively produce novel and potentially useful modified alternan.