Surveying the relation between the acid (citric, gluconic and oxalic acid) production and the osmotic pressure of the mycelium in many cases, the following results were obtained. 1. In good acid production, the initial osmotic pressure is as high as 1.6-1.7M. 2. The initial osmotic pressure of the old strain, not pre-cultured and of the nitrogen-mustard treated strain is low. 3. When the osmotic value decreases to about 1.3-1.2mol, the acid production is accelerated and then increases gradually during the period when the osmotic value is 1.0-0.9 M. 4. Optimum concentration of sucrose in basal medium is 10-14%. At the growth stage 10% of sucrose is preferable, while at the stationary stage, 14%. 5. Effects of deficiency and excess of N and K are remarkable, as compared with those of Mg and Fe. It may be said that as in the case of sucrose, a lower concentration of N is preferable at the grwoth stage and a higher concentration of it at the stationary stage. 6. If 1-3% methanol is added in basal medium, the irregular forms of hyphae are observed at the growth stage and in many cases more citric acid is produced. In such cases, citric acid production is more promoted than at the ordinary osmotic value. If we add agar and starch moreover we have much more citric acid production. 7. As an application of this observation, we can have more citric acid production, when the initial concentration of NH4NO3 in basal medium is 1% and increases to 2% on the 3rd day.
1)The experiments were undertaken to study the influences of certain enzyme inhibitors on the photoperiodic responses of a water fern, Salvinia natans. 2) Plants were subjected to 8-hour photoperiod for 5 days. KH2AsO4, NaF and malonic acid were added to the nutrient solution throughout the light and the dark periods. KCN and NaN3 were applied during the light or the dark period, and CO only during the dark period. 3) KH2AsO4 and NaF inhibited the development of sporocarp in lower concentrations, and the initiation of sporocarp in higher concentrations. The inhibitory effect of KH2AsO4 was removed by the simultaneous application of KH2PO4. 4) KCN and NaN3, either being an aerobic inhibitor, inhibited sporocarp initiation especially when given to the plant during the light period. These enzyme inhibitors, however, promoted photoperiodic responses when supplied together with glucose. 5) CO and malonic acid considerably promoted sporocarp initiation. 6) It is considered that the interception of citric acid cycle promotes photoperiodic response, and that the inhibitors of heavy metal-containing enzyme inhibit photoperiodic response by preventing photosynthesis or related processes, but promote it if the sufficient carbohydrates are given to the plant.