Effects Various Adsorbents on Mycelium Formation and Mycophenolic Acid Production by Pénicillium brevicompactum

Abstract

A drug-resistant mutant, No. 4–23–11, which had been derived from Pénicillium brevicompactum ATCC 16024, was cultured in a liquid medium for the production of mycophenolic acid (MPA) in the presence and absence of various adsorbents, that is, celites, zeolites, aluminas, talc, silica, charcoals, carbon blacks, natural graphite and carbonaceous mesophase spheres. In the absence of an adsorbent, MPA production (0.2 ~4.8 g/1) and the size of mycelium pellets (5~0.5mm) markedly depended on the concentration of spores inoculated (10⁴~ 10⁷/ml), whereas in the presence of one of these adsorbents, small pellets (smaller than 1 mm in diameter) were formed and the high production of MPA (4.5 — 5.4 g/1) was observed, independently of the spore concentration between approximately 10⁴~ 10⁷/ml. Microscopic observation of the pellets revealed that numerous particles of the adsorbents adhered to the surface of the hyphae. These results suggest that the adsorbents might interfere with the adhesion of hyphae to each other and thus retard the formation of large pellets.