Azuma Okuda

Nitrogen-fixing microorganisms in paddy soils: VI

Abstract In the preceeding paper (1), it was reported that when R. capsulatus is mixed with B. subtilis, in spite of no nitrogen fixation in separate cultures, by using a glycerol or starch medium, the combination was able to fix molecular nitrogen and it seems that there is a correlation between the production of pyruvic acid and the nitrogen fixation in the mixed culture.

NITROGEN-FIXING MICROORGANISMS IN PADDY SOILS : V. : Nitrogen Fixation in Mixed Culture of Photosynthetic Bacteria (Rhodopseudomonas capsulatus species) with Other Heterotrophic Bacteria (1)

Abstract P. W. WILSON (1) reported that the contaminated culture of azotobacter was superior to the pure culture in the fixation of nitrogen. We (2) also reported that the nitrogen fixation by photosynthetic bacteria, Rhodopseudomonas capsulatus associated with various microorganisms was superior to that in the pure culture.

Nitrogen-fixing microorganisms in paddy soils (Part 2) distribution of blue-green algae in paddy soils and the relationship between the growth of them and soil properties

Abstract As was shown in the previous reportl), a close connection between the photosynthetic autotrophs and nitrogen fixation in paddy soils was demonstrated.

NITROGEN-FIXING MICROORGANISMS IN PADDY SOILS : (PART 3) DISTRIBUTION OF NON-SULPHUR PURPLE BACTERIA IN PADDY SOILS

Abstract The possible significance of blue-green algae in the nitrogen economy of paddy soil has been pointed out by many investigators.

Identification of amino acids in humic acid

Abstract Davidson, Sowden and Atkinsonl) in 1951 reported on the amino acids in the three soil organic matter fractions, and Stevenson, Marks, Varner and Martin~) in 1952 reported on the identification of eight amino acids from clay-adsorbed organic colloids in Brookstom slity clay loam. Also, some investigations on these amino acids have been carried out in our laboratory.

Nitrogen-fixing microorganisms in paddy soils (Part 1) Characteristics of the nitrogen fixation in paddy soils

Abstract In most paddy soils, as is already well-known, the crop yield goes on decreasing just for the first few years and then stabilizes at a comparatively high level with no supply of fertilizer or manure.

NITROGEN-FIXING MICROORGANISMS IN PADDY SOILS IV. : Nitrogen Fixation by Photosynthetic Bacteria (Rhodopseudomonas capsulatus species) under Various Conditions

Abstract In 1949, GEST and KAMEN (1,2) reported that Photosynthetic bacteria can fix molecular nitrogen. LINDSTROM et al. (3,4) tested the nitrogen fixing ability of five species of photosynthetic bacteria under the following four conditions; 1) anaerobic light, 2) aerobic light, 3) aerobic dark, 4) anaerobic dark. As the result of the experiment, they certified that it Was only under the anaerobic light condition that the bacteria can fix molecular nitrogen.

Nucleic acids in the culture fluids of Rhodopseudomonas capsulatus and other heterotrophic bacteria

Abstract In previous papers (1,2), it was reported that in cultures of R. capsulatus mixed with other heterotrophic bacteria nitrogen fixation is accelerated and there is some production of slime substances (3), exchange of pyruvic acid (4–6), amino acids, carbohydrates (7) and others in these mixed systems. There is also symbiotic association between R. capsulatus and other heterotrophic bacteria (Azotobacter) in nature (8).

Foliar absorption of nutrients IV: The effect of some organic compounds on the absorption of foliar applied phosphoric acid

Active surface agents are often added to spray solutions to facilitate the uniform wetting and coveringg of the leaf surfaces1),2). Some have reported that the addition of active surface agents inc...

Purification of humic acid by the use of ion exchange resin

Abstract The humic acid fraction, extracted from soil by alkali or neutral salt solution and acid-recipitated, is generally contaminated with a considerable amount of inorganic matter. The presence of the inorganic matter is often undesirable for studies on humic acid. The inorganic matter is generally taken off by ultrafiltration or electrodialysis. But these methods take time and are unsuitable for the bulk preparation of humic acid.