1.Improvement of kojic acid producibility through somatic recombination was attempted with the following results: (1) One white leucineless strong producer and three yellow lysineless weak producers were recovered from a heterozygous diploid which was produced between a white leucineless weak producer and a yellow lysineless strong producer. (2) One of the segregants obtained from the above mentioned diploid strain produced about fourty percent larger amount of kojic acid than the parental producer, yellow lysineless strain. (3) In general, the breeding effect through this process did not turn out to be so significant as expected. 2. Protease activity of three haploid, three diploid, one triploid, and one tetraploid strains were compared by wheat bran koji method, with the result that the protease activity of two diploid and one tetraploid strains was significantly higher than any of the haploid ones.
1) Sixty-four strains of hiochi-bacteria isolated from spoiled saké have been used for this research. 2) Hiochi-bacteria have been recognized to belong to the mesophilic lactic acid bacteria. They can be divided into homofermenters and heterofermenters, and each of these two groups can be further classified by whether they demand hiochic acid or not. 3) This system of classification of hiochi-bacteria is apparently identical with the combination of the classical systems of YAMASAKI and of TAKAHASHI, who classified by plus or minus of gas-formation, and plus or minus of growth in the media other than saké, respectively.
Further examinations have been carried out for identification and classification of hiochi-bacteria, from the stand point of lactic acid-bacteriology. The characteristics of ‘true hiochi-bacllli’, both homo- and heterofermenters, do not coincide with those of any species which have hitherto been known. So the authors have proposed the names Lactobacillus homohiochii and L. heterohiochii nov. sp. respectively. The 64 strains used throughout this research are classified as follows: Spheres: Heterofermenting D-lactic acid former. ....Leuconostoc mesenteroides (1 strain). Rods: Heterofermenting, as a rule DL-formers. Hiochic acid independent, xylose is fermented. .... Lactobacillus fermentum (4 strains). Hiochic acid essential, ferment only glucose and fructose. ....Lactobacillus heterohiochii n. sp. (44 strains) Homofermenting Hiochic acid independent, pentose-fermenting, DL-former ....Lactobacillus plantarum (1 strain). pentoses not fermented, DL+L-former ....Lactobacillus acidophilus (3 strains). Hiochic acid promotive, D+DL-formers. ....Lactobacillus homohiochii varieties (4 strains). Hiochic acid essential, D- or D+DL-formers ....Lactobacillus homohiochii n, sp. (7 strains).
Using Chlorella ellipsoidea as material, investigations were made to examine whether the rates of growth and photosynthesis of algal cells (in high population densities) could be accelerated by the effect of phosphorescent particles ("copper-activated Zn-Cd-S-phosphor") suspended in the medium. It was revealed that, at least with the experimental arrangement adopted, there was neither accelerating nor suppressing effect attributable to the presence of the substance.
1. Using genetically blocked yellow mutant of Aspergillus sojae 260, some environmental conditions which favor the Conidial color change from yellow to green were investigated. 2. In the presence of culture filtrate or mycelial mat extract of other fungi, the yellow conidia of the Y1 strain changed their color into green. However, the degree of greenization with these substances was not so sufficient as to make it possible to draw a decisive conclusion. 3. With the presence of copper and chlorine ions, the yellow color changed almost completely to green. The other halogens such as bromine and iodine could replace the chlorine ion. The color change was proved to occur only in yellow mutants of Asp. Sojae and Asp. oryzae. Other mutants such as white and brown ones did not show such a phenomenon. 4. The green conidia thus obtained returned to yellow when they were transplanted on the ordinary media such as Czapek's agar and malt extract agar. It is apparent, therefore, that the color change was merely physiological modification. 5. For the development of green color, the original green strain required copper ion, but the yellow mutant required both copper and halogen ions. 6. The possible role of halogen ions and that of copper ions in inducing green conidia formation were discussed.
Uniformly 14C-labelled adenine and guanine were isolated in fairly pure form from the nucleic acid fraction obtained at the same time when 14C-labelled amino acids were isolated from the protein fraction of chlorella ellipsoidae.
In investigating the causes of deterioration of cereal grains under the influences from microorganisms, the author has been of the opinion that the most important approach is to trace the movements of microflora in an ecological system termed cereal grains. This microbiological studies on the cause of the deteriorated rice, have been carried out in the same light. The results of this investigation are summarized as follows. (1) The significant change of microflora after the normal maturity, would take place from immediately after to some time after polishing. In the freshly-polished new rice kernel after removing husks (inner- and outer-glume), bran layer (pericarp, endosperm, ) and sometime a part of aleuron layer, the microorganisms show significant decrease in number and Yellow Pseudomonas and some moulds known to invade rice during cultivation, such as Alternaria, Curvularia, Helmintosporium, Cepharosporium, etc. are found still remaining. However, soon after the polished rice is put in storage, the number of these microorganisms rapidly increase and instead come moulds such as White Aspergillus, bacteria such as Bacillus megatherium and Streptomyces begin to predominate. (2) In normal rice which passed the wet season in storage from of polished rice, fairly many moulds such as Aspergillus mostly consisting of White Aspergillus and Penicillium are found and not much change is seen in bacteria in which Bacillus megatherium still predominates. But, it is a noteworthy fact that particularly many Streptomyces such as Streptomycesdiastaticus, etc. are found in this specimen. (3) In the polished rice after passing the wet season in storage, there is some rice of which deterioration can be recognized by visual inspection, for example FESCO standard. The common feature of these deteriorated rice is that Aspergillus, Penicillium and Streptomyces are found to be considerably more than in the normal rice. Therefore, deterioration of rice caused by microorganisms is considered to take place in Thailand depending upon the extent of increase of Aspergillus, Penicillium and Streptomyces during the storage period of polished rice. (4) No attention has been paid to Streptomyces found in rice up to the present day. But, many of these were found not only in almost every specimen of normal polished rice but also in freshly-polished rice from the unhusked rice after one years storage. And these Streptomyces of rice mainly consist of Streptomyces diastaticus like strains. And it was found that some of these gaves considerably poisonous function when mice were fed with food containing rice with the strain grown on it.
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