A strain of blue green alga, Cyanidium caldarium GEITLER, was isolated from the sample material collected from a hot spring in Yumoto, Nikko, Japan. Consistent subcultures were obtained and the growth responses of the organism towards various environmental conditions were investigated.
The alga was found to be markedly thermophilic and extremely acidophilic in nature, most favorable growth taking place at 45°-50° and pH 3.0. The changes in the metabolic activities of the organism during the course of culture were followed.
The effect of hydrogen ion concentration, temperature, light intensity and carbon dioxide concentration on the rate of photosynthesis was investigated. The optimum hydrogen ion concentration was pH 3.0. The optimum temperature lied at 55°. The apparent heat of activation (in respect to the dark reaction of photosynthesis) amounted to 17 Kcal for the temperature range 55°-40°, and 7 Kcal for 40°-30° (pH 3.0). The saturating intensity of the light was found to be about 10⁵ Lux or higher with sufficient amount of carbon dioxide in the medium. Under sufficiently strong illumination, the half-saturation of photosynthesis was reached at a concentration of carbon dioxide of ca. 1.2×10^-4 mol/l (or about 0.6% CO₂ in air: pH 3.0, 45°). These findings were compared with the data reported for the green alga, Chlorella.

抄録全体を表示

Two new strains (No. 507 and No. 508), isolated from the soil collected respectively at Higashinoshiro City (Akita Prefecture) and at Kuchian Station (Hokkaido) in July 1955, were identified to be a new species, Streptomyces spiroverticillatus, basing on morphological and cultural studies. The specific epithet shows the characters forming spirals and whirls on the aerial mycelium.

抄録全体を表示

With the purpose of elucidating the annual cycle of algal flora at a certain “fixed” location on the Pacific coast, regular observations were carried out at the “observation reef” defined by the author at Manadzuru Peninsula, Kanagawa, Japan.
The results of the regular inspection of the place from November, 1937 to October, 1938 were described with respect to the number of algal species discovered at the observation reef, with special reference to the first appearance, the maximal vigor of growth and the final disappearance of each algal form.
Summing up through the year, there were 88 species of algae discovered from the observation reef, which belonged to the families of Chlorophyceae (9 species), Phaeophyceae (22 species) and Rhodophyceae (57 species).
The seasonal changes in the algal formation were investigated by following the life cycle of each algal form from its first appearance on the reef to its final disappearance from the place. Formation of cystocarps and tetraspores were also followed with the red alga forms.

抄録全体を表示

(1) Photosynthesis of natural phytoplankton was studied under field condition. The amount of phytoplankton was determined by chlorophyll content of lake weter and the photosynthetic rate was expressed by oxgen in mg. evolved by one mg. chlorophyll.
(2) The effect of diurnal change of light intensity on the photosynthesis was remarkable. The light saturation of the photosynthesis was found at about 50per cent of the surface light and the further increase of light caused even inhibition in photosynthesis.
(3) The photosynthetic rate of phytoplankton varied considerably in the course of a year and showed two marked pulses in early summer and in autumn. However, the feature of variation of photosynthesis much differs with lake types.
(4) As the maximum photosynthetic activity under field condition, 80mg.-90mg. O₂/chl. mg./day in eutrophic lake, 30mg.-40mg. O₂/chl. mg./day in mesotrophic lake and 10mg.-20mg. O₂/chl. mg./day in oligotrophic lake were measured respectivelly.
(5) The photosynthetic capacity relates with the amount of chlorphyll fairly strictly.
(6) Parallelism between the photosynthetic rate and the growth rate of phytoplankton population was recognized.

抄録全体を表示

In this series of papers, the writer has traced the vascular strands of the spikelet (1940a), the male inflorescence axis (1939), the axillary shoot (1958), the leaf (1940b) and the adventitious root (1958) to the mother axis with a view to examine their behaviours, and he has also studied the origin and structure of the nodal plexus (1942) and the developmental order of the vertical bundles of the stem (1946). Consequently general consideration to the vascular construction has been given in this paper with special reference to the vascular connection of the lateral organs with their mother axis.
As pointed out previously (1940b, 1942), two systems of vascular bundles, one inside of the other and independent without being directly connected with each other, are distinguished throughout the cauline axis: the outermost peripheral bundles and the compound ones constitute respectively an outer system and an inner system at rather peripheral regions of the axis. The trace bundles from the lateral organs, i. e. the spikelet, the secondary inflorescence axis, the axillary shoot, the leaf and the adventitious root, are equally connected with those two bundle systems of the mother axis. Although in the case of the lateral shoot subtended by a foliar leaf, the behaviour of branch trace strands are greatly modified and complicated, owing to a large number of bundles, the presence of leaf traces and the development of nodal plexus, the fundamental pattern of the vascular connection with the mother axis is interpreted to be homologous to the case of dicotyledonous plants, if the horizontal vascular plexus is left out of consideration. The only significant difference of vascular construction between maize and dicotyledonous plants is that the vascular system in maize is of dicyclic construction from the first foliar node upwards to the pedicel of the spikelet.
The lateral organs of phyllome nature, except the floral phyllomes, bring about the multilacunar nodal structure of the mother axis, while those of cauline nature bring about the unilacunar, regardless of their vascular constructions which are complicated as in the axillary shoot or simple as in the pedicel of the spikelet

抄録全体を表示