A high-biomass, iron-enriched Saccharomyces cerevisiae ZYF-15 was constructed by interspecies protoplast fusion. Under optimal fermentation condition, the biomass and iron content of the strain reached 11 g l(-1) and 25 mg Fe g(-1) dry cells, respectively. About 96% of enriched iron is converted into organic iron, which is mainly in cell walls and vacuoles with some bound to DNA, RNA and protein.