Pigment Production from Immobilized Monascus sp. Utilizing Polymeric Resin Adsorption

Pigment production by the fungus Monascus sp. was studied to determine why Monascus sp. provides more pigment in solid culture than in submerged culture. Adding a sterilized nonionic polymeric adsorbent resin directly to the growing submerged culture did not enhance the pigment production, thus indicating that pigment extraction is probably not a factor. Monascus cells immobilized in hydrogel were studied and exhibited decreased pigment production as a result of immobilization. This result is thought to be due to diffusional resistance of the pigment through the hydrogel beads. Addition of the adsorbent resin to the immobilized Monascus culture increased both the maximum pigment yield and the production rate above those of the free-cell fermentations. The provision of a support for the mycelium may explain enhanced pigment production by the solid-state culture. These results indicate that product diffusion from immobilized cell systems can be the limiting factor and that in situ extraction is one possible way to circumvent this problem.