A yeast strain Y-2A producing a large amount of biosurfactants was isolated from oil-containing wastewater and identified as Wickerhamiella domercqiae by BIOLOG analysis and routine yeast identification method. The crude biosurfactants produced from Y-2A were obtained by extract with ethyl acetate and proved to be a mixture of glycolipids by thin layer chromatography (TLC). The main product was separated and purified by HPLC and then characterized as sophorolipid by nuclear magnetic resonance (NMR) and mass spectroscopy (MS). This is the first report on sophorolipids produced from W. domercqiae. Subsequently, the cytotoxic effects of the sophorolipid on cancer cells of H7402, A549, HL60 and K562 were investigated by MTT assay. The results showed a dose-dependent inhibition ratio on cell viability according to the drug concentration <= 62.5 mu g/ml. These findings suggested that the sophorolipid produced by W domercqiae have anticancer activity. (c) 2006 Elsevier Inc. All rights reserved.