SYNTHESIS OF PROTOPORPHYRIN IX INDUCED BY 5-AMINOLEVULINIC ACID IN YEAST-CELLS IN THE PRESENCE OF 2,2'-DIPYRIDYL

5-Aminolevulinic acid (ALA), a precursor of porphyrin synthesis, incre ased the production of various porphyrin compounds in Candida guillier mondii cells. Metalloporphyrins and protoporphyrin IX (PPIX) were pred ominantly accumulated, respectively, at ALA concentrations of 0.2-0.4 mM and at those higher than 1.5 mM. 2,2'-Dipyridyl which complexed wit h bivalent metals significantly increased the content of endogenous PP IX even at ALA concentrations lower than 0.5 mM. Under these condition s, the yeast sensitivity to photodynamic effect of visible light (400- 600 nm) dramatically increased due to photosensitization by endogenous PPIX.