Glycine Betaine: Reserve Form of Choline inPenicillium fellutanum in Low-Sulfate Medium

ABSTRACT In spite of choline’s importance in fungal metabolism, its sources in cytoplasm have not been fully established. 13C nuclear magnetic resonance analysis of mycelial extracts from day-5Penicillium fellutanum cultures showed that, as well as choline-O-sulfate, intracellular glycine betaine is another reserve form of choline, depending on the availability of sulfate in the culture medium. These observations are discussed relative to the multiple roles of choline and its precursors in P. fellutanum.