Candida bombicola:: production of novel alkyl glycosides based on glucose/2-dodecanol

Candida bombicola produces glycolipids containing sophorose and a glycosidically/esterically bound omega- or (omega - 1)-hydroxy C-16(18) acid. Here we describe novel glycolipids from this source. Glucose and 2-dodecanol were used for the cultivation of the yeast, one part of the racemic secondary alcohol being connected directly with a glucose or a sophorose unit. A relatively high content of yeast extract, up to 4 g l(-1), and subsequently higher biomass concentrations favoured the production of novel products. The provision of 150 g l(-1) glucose and 15 g l(-1) 2-dodecanol resulted in maximum production of 22 g l(-1) novel alkyl glycosides (more than 90% novel products). The molecular structures were analysed by gas chromatography, fast atom bombardment/mass spectrometry, H-1- and C-13-nuclear magnetic resonance and optical rotation studies. Sophorose and glucose were detected as carbohydrate moieties, (S)-(+)-2-dodecanol (88%) was found to be the major lipid moiety. The new glycolipids are suitable biosurfactants, reducing the surface tension of water from 72 mN m(-1) to 32-38 mN m(-1).