Phosphate regulation of phosphatases in submerged cultures of Claviceps purpurea 129 producing clavine alkaloids

Summary Claviceps purpurea strain 129 was cultivated under submerged conditions in a sucrose-citrate medium containing high (36.8 mM) or low (1.84 mM) KH₂PO₄ concentrations. The permeabilized cells and culture supernatants contained alkaline and acid phosphatases. In the medium containing a high phosphate concentration, the synthesis of extracellular phosphatases was repressed, but that of cellular phosphatases was not. Extracellular phosphatases, especially alkaline phosphatases, were derepressed by transferring the mycelium into a phosphate-free medium. This derepression was inhibited by cycloheximide. In the presence of cycloheximide, the activities of the cellular phosphatases decreased markedly, indicating turnover of these enzymes. The cellular acid phosphatase was inhibited by phosphate (0.025 M–0.1 M) and NaF (0.01 M) while the cellular alkaline phosphatase was only inhibited by phosphate. Both cellular and extracellular alkaline phosphatases were more sensitive to repression by phosphate than the acid phosphatases. The alkaloid synthesizing enzymes were: a) present in mycelia grown in high levels of phosphate and b) activated by decreasing the intracellular phosphate level.