By using mutants of Aspergillus sojae, it was demonstrated again that the heterocaryons and the heterozygous diploids irradiated by ultraviolet light gave rise to diploids and somatic segregants in higher frequencies. These two effects of ultraviolet light were compared with the so-called inactivation (killing) effect of UV. The haploid conidia inactivated by ultraviolet light were reactivated by visible light, while visible light gave no significant effect on diploidization and segregation. It was concluded, therefore, that the mechanism of UV function on inactivation is different from that on diploidization and segregation. Differences between two functions of UV, on diploidization and on segregation, are not known.
A method of preserving blue-green algae in a visible state for a long time for seeding purposes was examined. As a practical and economical way of preservation, a method of mixing the algal suspension with sand and drying in the sunlight was devised. The alga thus dried retained its capacity for growth unimpaired for about two years.
1) Oxygen absorption rates in bubble aeration were determined polarographically together with the photographic observations of aeration. 2) Calculating the interfacial area of bubbles, oxygen transfer coefficients which are free from undesirable effects were determined under an assumption that the liquid film resistance is controlling. 3) Using pure oxygen gas, in which no gas film exists, the above assumption was found reasonable in a range of this experimentation. 4) The volume-surface mean and the ascending velocity of bubbles do not differ markedly in a range of air flow rates of these experiments. Thus, the liquid film coefficient seems to be independent of the air flow rate. 5) Effects of organic substances on the liquid film coefficient were studied.
1) Growth, respiration, and dissolved oxygen concentration curves were analysed. From such analyses, it is feasible to determine an over-all coefficient Kd of oxygen transfer in biological systems without resorting to the so-called "sulfite method". 2) Assuming that an over-all coefficient Kd of oxygen transfer can be employed as a measure in scaling-up, a procedure to examine air flow rate required in a large-scale fermentor was shown.
The present authors, in this paper, reported a new and a peculiar phenomenon caused by a microorganism concerning with steroidal fermentation and suggested an economical process for the industrial preparation of prednisolone from hydrocortisone. In this process the growing culture of Arthrobacter simplex ATCC 6946 was employed as microorganism, hydrocortisone in solid state was used as substrate and the fermentation was carried out aerobically in this heterogeneous phase. The enzymic reaction of the organism proceeded onesidely to form prednisolone (Δ1-hydrocortisone), and thus, the substrate in solid form was apparently transformed into the crystals of the product in the heterogeneous reaction mixture. For this microbial reaction the authors proposed the name "pseudo-crystallofermentation."
1. A strain of microörganism, Bacillus pulvifaciens IAM N-19-2, isolated and identified in this laboratory, was used for oxidative fermentation of various steroids and corresponding 1-dehydro compounds were obtained. 2. Oxidative fermentation of 4-ene-3-one and 5-ene-3 β-ol type steroids in shake flask resulted in the formation of 1, 4-diene-3-one type steroids, the oxidation stopping at this point. 3. Oxidation of 5-ene-3β-ol type steroids was found to result in dehydrogenation of 1-2 position after formation of 4-ene-3-one type intermediate. 4. Tank culture of dehydroepiandrosterone, not possessing a sidechain at 17-position, was found to give a hydroxylated compound, affording, at the same time, 1-2 dehydrogenated oxidation product and a triketone. 5. The route of oxidation of dehydroepiandrosterone by Bacillus pulvifaciens IAM N-19-2 was considered from the foregoing experimental results.
1. Soil microorganisms play an important role in plant nutrition. Many species of microbes, especially those that abundantly develop in the rhizosphere, exert a direct influence on plant nutrition. These microbes synthesize various biologically very active organic compounds and transmit them to the plants. The latter absorb through their roots the microbial metabolites and use them as sources of additional nourishment. 2. The present paper shows that some bacteria aid in the accumulation of amino acids in plant tissues. In the presence of certain species of activating bacteria the amount of amino acids in the plant tissues increases 50-100 per cent or more. In leguminous plants more amino acids are accumulated under the influence of active nodule bacteria. As a rule, the more nodules on the roots, the more free amino acids in the tissues. Greater concentration of amino acids is also observed under the influence of certain non-nodule bacteria-Bacterium sp., Ps. fluorescens, etc.. A particularly high increase in amino acids in leguminous plants is observed when they grow in the presence of Ps. fluorescens. 3. A similar effect is produced by certain activating bacteria on non-leguminous plants. The tissues of cereals (maize, wheat, barley, etc.) also show an increased accumulation of free amino acids in the presence of bacteria although to a lesser extent than those of the leguminous plants. 4. Certain activating bacteria influence the acumulation of phosphorus containing organic compounds in plant tissues. These compounds are in some extent synthesized by bacteria and are transmitted to the plants through the roots. This was shown in the experiments with tracer phosphorus P32 with the simultaneous use of the method of paper chromatography.