This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was made that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste (S0), soaked soybean-soypaste (S1), roasted soybean-soypaste (S2), and steamed soybean-soypaste (S3) from soybean (60 %), rice koji (30 %) and salt (10 %) respectively in order to investigate the changes of enzymes activity (amylase, protease, lipase and lipoxygenase activity) during fermentation of them. Amylase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and S0>S1>S2>S3 in the soybean treatments. Protease activity was in the order of natural fermented microorganisms>Asp. niger>Asp. oryzae>Asp. awamori in the microorganisms, and S3>S2>S1>S0 in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of S0>S1>S3>S2 in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and S0>S1>S3>S2 in the treatments.

Grasses have been found to endure iron-deficiency by excreting from their roots mugineic acids which are able to dissolve ferric compounds by forming Fe(III)-complexes. However, mugineic acids were suspected to be rather quickly decomposed by soil microorganisms. This means that mugineic acid-decomposing microorganisms, if present, will mitigate the beneficial effect of the mugineic acids. In addition, the relation between excretion of mugineic acids and mugineic acid-decomposing microorganisms is considered to be a simple model of the relation between plant roots and their rhizospheric microorganisms in general. According to these considerations, we searched for mugineic acid-decomposing microorganisms in the water-cultured iron-deficient barley. Microflora both in the cultural solution and on the root surface appeared to be fairly simple and composed of bacteria. Six strains of mugineic acid-decomposing bacteria were isolated from the barley roots. On the contrary, no mugineic acid-decomposing bacterium was isolated from the cultural solution. This result suggests that the mugineic acid-decomposing bacteria are liable to be adsorbed on the surface of roots. One strain of the bacteria,which could quickly decompose mugineic acid, was judged to belong to Pseudomonas, though no known species were identical with this strain

Sugar beet is often cultivated for several years on the same fields, using many pesticides. We have therefore studied the effects of a pesticide programme on soil microorganisms and sugar beet yields in Perniö and Laukaa. The pesticides in use were thiram, hymexazol, dimethoate, phenmedipham and metamitron and, in Laukaa only, alloxidim-Na. Pesticides were used either in the normal doses or at 150 % of the normal dose. The normal doses of pesticide application had a favourable effect on sugar beet yields in both experiments. The sugar yield was higher in plots with the normal pesticide doses than in the control plots. The overdoses increased neither the sugar beet yields nor the sugar yields as compared to the normal plots. The soil microorganisms were affected by pesticides in some but not in all cases. The most sensitive were the ureolytic microorganisms and the dehydrogenase activities.