Raspberry ketone from submerged cultured cells of the basidiomycete Nidulaniveo-tomentosa

The basidiomycete Nidula niveo-tomentosa produced 4-(4-hydroxyphenyl)-butan -2-one (raspberry ketone), one of the character impact components of raspbe rry flavor, and its corresponding alcohol. A systematic attempt was made to improve the productivity of this fungus. Variation of nutrient medium comp osition, precursor amount, time of supplementation, and cultivation period yielded a 50-fold increase in metabolite concentrations. Raspberry ketone a nd alcohol were easily isolated from the culture medium by solvent extracti on. Glycosidically bound forms or accumulation of raspberry compounds in fu ngal cells were not detected. This microbial process offers an alternative for the production of natural raspberry flavor.