Abstract
Continuous culture and batch culture experiments on the control of morphogenesis of the acquatic phycomycete Blastocladiella emersonii led to the following conclusions: (1) The metabolism of Blastocladiella under the conditions of these experiments was highly oxidative, all of the substrate being accounted for as unused substrate, fungus carbon and CO2. (2) Morphogenesis was dependent on potassium-ion concentration, ephemeral sporangiate organisms developed in low K+ concentration and resistant sporangiate organisms developed in higher K+ concentration. (3) Morphogenesis in these experiments was independent of CO2 partial pressure and pH value. (4) Morphogenesis was also dependent on an ionized species of carbonic acid (bicarbonate, carbonate) depending on the medium used. Ephemeral sporangia developed at low concentrations of these ions, K+, HCO3-and CO3 2-, and resistant sporangia developed at higher concentrations. (5) The potassium and magnesium content and pH value of the organisms were independent of the pH value and potassium concentration of the medium over the ranges studied, and of the sporangium type produced by the organisms. The continuous culture apparatus used is described and continuous culture theory applicable to experiments in morphogenesis has been developed and tested.