MANAGEMENT AND GENETIC CHARACTERIZATION OF AGRICULTURAL AND BIOTECHNOLOGICAL MICROBIAL RESOURCES
Location: Bacterial Foodborne Pathogens & Mycology Research Unit
Title: Production of sophorolipids biosurfactants by multiple species of the Starmerella (Candida) bombicola yeast clade
Submitted to: FEMS Microbiology Letters
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 21, 2010
Publication Date: August 25, 2010
Citation: Kurtzman, C.P., Price, N.P., Ray, K.J., Kuo, T. 2010. Production of sophorolipids biosurfactants by multiple species of the Starmerella (Candida) bombicola yeast clade. FEMS Microbiology Letters. 311(2):140-146.
Interpretive Summary: This research describes the production of non-petroleum derived chemicals, called sophorolipids, through application of "green technology." Sophorolipids are surfactants, or wetting agents, that are produced by certain yeasts and can be used to manufacture household and industrial detergents. At present, most surfactants are derived from petroleum. In this study, we examined 19 unique yeast species for the formation of sophorolipids and discovered that five produce levels that are of industrial interest. Furthermore, these five species are genetically related as determined from analysis of DNA gene sequences. One of these high-producing species has never been previously described, and this study demonstrates the importance of genetic analysis in the search for biotechnologically important microorganisms.
Sophorolipid production was tested for 26 strains representing 19 species of the Starmerella yeast clade, including S. bombicola and Candida apicola, which were previously reported to produce sophorolipids. Five of the 19 species tested showed significant production of sophorolipids: S. bombicola, Candida apicola, C. riodocensis, C. stellata and a new species, Candida sp. NRRL Y-27208. Phylogenetic analysis of sequences for the D1/D2 domains of the nuclear large subunit rRNA gene placed all sophorolipid producing species in the S. bombicola subclade of the Starmerella clade. MALDI-MS analysis demonstrated that S. bombicola and C. apicola produced a lactone form of sophorolipid, whereas C. riodocensis, C. stellata and Candida sp. NRRL Y-27208 produced predominantly free acid sophorolipids.