Monitored environment system to control cell growth, morphology, and metabolic rate in fungi by oxidation-reduction potentials.

A device for the adjustment, maintenance, and monitoring of a desired oxidation-reduction potential in a liquid environment is described. The filamentous species, Penicillium lilacinum and Trichophyton schoenleinii, and the dimorphic species, Histoplasma capsulatum, developed budding yeastlike cells when grown in a liquid medium with a low oxidation-reduction potential. When the organisms were inoculated into fresh medium, they returned to the filamentous condition as the oxidation-reduction potential was restored to a more positive (oxidizing) environment.