The color reaction of 6-deoxy-hexoses by sulfuric acid was examined in order to apply to the spectrophotometric determination of these sugars. The procedure includes heating a mixture of 2ml of sample and 4ml of 81_??_82 wt.% sulfuric acid for 20 minutes in boiling water and measuring the optical density at 458 mμ. The optical density showed a linear relationship to the concentration over the range of 50_??_140, μg/2 ml of rhamnose, and the standard deviation being 0.002_??_0.004 in optical density. Presence of small amount of other hexoses, pentoses, and uronic acids gave little effect under the condition used. When larger amount was contained, the result can be calibrated by the optical density at 530 mμ. Little or no effect resulted by other substances tested, except dichromate, nitrate, tannic acid, and ascorbic acid, which could significantly interfere if large amount was present

View full abstract

It was revealed that a bacteriophage provoked the inhibition of lactic acid formation during fermentation of lactic acid beverage. A relatively virulent bacteriophage was isolated and named phage J₁. This phage exhibited a very narrow host range; Lactobacillus acidophilus strain Shirota and a related strain isolated from the same source as that of the former strain were exclusive hosts among tested 15 Lactobacilli. Calcium ion was found essential for the multiplication of the phage. The pH value lower than 4.5 suppressed the phage growth. The phage particles were inactivated by treatment at 70°C for 40 min. or 90°C for 5 min. The time course of bacterial growth after infection was analysed. The higher the multiplicity of infection, the faster was the bacterial lysis. The secondary growth being probably deu to the resistant cells was extremely retarded when the multiplicity was low.

View full abstract

The purpose of this investigation was to determine the effect of FeS on the release of soluble Mn from low grade MnO₂ ore by T. thiooxidans. In this investigation, chemical grade MnO₂ was used in place of low grade ore. In MnO₂-containing medium, the addition of either one of FeS, FeSO₄, or Fe₂(SO₄)₃ caused the stimulation of the growth rate of T. thiooxidans, and 2_??_10 times as much soluble Mn was released compared with the culture without the addition of the iron compound. Since the addition of CuS and ZnS had not any effect on the growth of organisms in the medium containing MnO₂, the stimulating effect of iron sulfide on the release of soluble Mn from MnO₂ should be the acceleration of biological and/or chemical reduction of acid-insoluble Mn⁴⁺ to soluble Mn²⁺.

View full abstract

In order to investigate the concentration of the bacterial leaching solution containing dilute MnSO₄ by electrolytical concentration using ion-exchange membrane, ten sheets of the membrane (2×20cm²) were placed at intervals of 3mm, and each compartment was filled with the mixed solution of MnSO₄ and H₂SO₄ and circulated under the proper electric current densities. The total capacity of the apparatus was 130ml and the circulating rate was 21/min. When pH of the original solution was in the range of 1.7_??_3.3, the concentrating ratio was not affected with pH, however the electric current efficiency in such acidic solution was lower compared with that in other neutral salt solution.
T. thiooxidans cultured ordinarily in flask was killed in 20 hours at 10 V (A. C.), 0.75_??_0.90 amp/dm², however the organisms circulating in this apparatus survived under the following electric conditions. 1) Voltage; 80_??_110 V, Electric current density; 4 amp dm², 2) Voltage; 45_??_75 V, Electric current density; 10 amp/dm². Consequently, it was concluded that the dilute original leaching solution of manganese which contained living organisms would be able to be treated with the electrolytic condensation and then backed to the leaching vat and circulated continuonsly.

View full abstract

A study has been made of the Tiselius electrophoresis of casein and casein fractions in veronal buffer containing urea. It was found that κ-casein migrates in the β-peak when urea level is increased. In the buffer containing urea level of 7.0M, both α_s- and β-casein migrated in one peak but α-casein was resolved into 3 components. The most remarkable resolution could be obtained in the electrophoretic pattern of κ-casein preparation which migrated into at least six components.
The change in the electrophoretic pattern of whole casein solution when heated at temperature above 110°C for 30 minutes could be detected markedly using buffer containing 7 M urea. This indicates that the Tiselius electrophoresis using urea buffer is applicable for other investigation as rapid and simple method.

View full abstract

Fatty acid composition of glyceride and constituent of true wax in the lipids obtained from adult female insects have been analyzed by column, thin-layer and gas-liquid chromatographies. Eighty-three per cent triglyceride was the major component in the lipids from insect bodies. The fatty acid of the triglyceride had high contents of capric and lauric acid, 33.9, 38.5% respectively. Glycerides were not detected in the lipids obtained from the “Wax shell” which was excreted by insect. Twenty-two per cent true waxes and seventy-eight per cent other lipid classes composed the lipids. Cerotic acid and ceryl alcohol were the major constituents in the true wax'in addition to the small amounts of fatty acids (C₁₄, C₁₆, C₁₈, C₂₀, C₂₂, C₂₈) and fatty alcohols (C₁₈, C₂₀, C₂₄, C₂₈).

View full abstract

Thermal analysis was employed to study the thermal behavior of collagen including native and variously tanned collagen (chrome-, alum-, vegetable-, sulphonyl chloride- and formaldehyde-tanned collagen). The differential thermal analysis (DTA) curves of the native and tanned collagen samples under dry condition all showed distinct endothermic peaks at the temperature region of 50_??_200°C with the maximum peak at 130°C. The weight changes of the samples determined by thermobalance method, however, were not so distinct. Besides, it was observed that the thermal changes appeared in the peaks were not influenced by the type and the amount of tanning materials used, and the changes were irreversible. From these results, it is assumed that the occurred change is attributable to the heat transformation of the crystalline part of collagen. On the other hand, DTA curves of the wet collagen samples all showed endothermic peaks at the temperature corresponding to shrinkage temperature (T_s) determined by conventional method. The endothermic peak of DTA curve was about 10_??_17°C lower than the T_s. It is assumed that the endothermic change or shrinkage of collagen in an aqueous medium is resulted from the denaturation of amorphous part of collagen.

View full abstract

(1) The male adult rats were given daily C¹⁴-chlorella protein acid hydrolyzate. At definite intervals during this period mixed liver proteins, mixed muscle proteins and a few protein fractions of the muscle were prepared, and these specific radioactivities were measured. (2) The fraction of sarcoplasmic protein precipitated with half-saturated ammoninm sulfate had metabolic half life of 6.5 days, which was nearly equal to that of liver protein (5 days), while counterpart of this protein fraction was 10 days. (3) Specific radioactivities of myosin and actin reached to plateau on the 25 th day, and this may be interpreted as the evidence of existence of the life span in myosin and actin around this time. (4) The final levels of the specific radioactivities were different in each protein, and this has been interpreted to indicate the compartmentation of the free amino acid pool, being the direct precursor of the protein. (5) The final levels of the specific radioactivities were related inferentially to mobility as the reserve protein. The fraction of sarcoplasmic protein precipitated with half-saturated ammonium sulfate had the highest value of final specific radioactivity among the protein fractions of the muscle. This and others may imply that this protein fraction should be the reserve protein of the muscle.

View full abstract

Methylene Blue-active substances (MBAS) in vegetables interfere with the determination of the detergent residues by methylene blue colorimetric method. However, it was found that ABS detergent was satisfactorily recovered from the colored chloroform solution obtained by the Abbott's methylene blue method, by the application of thin-layer chromatography with silica gel adsorbent: In case of a mixture of chloroform and ethanol (5:1) as a solvent, the R_F value of the surfactant-methylene blue complex was nearly zero but the other MBAS (interfering substances) migrated on the definite R_Fs. On the occasion of 99% ethanol as a solvent, the complex was dissociated into its components and only the surfactant moved in accordance with its specified R^F.

View full abstract

Milk-clotting and blood-coagulating activities were determined using various proteinase preparations, mainly of microorganism origin, the substrate specificity of which on the oxidized insulin B chain was known. None of the proteinases which possessed hardly any milk-clotting activity attacked the peptide bond containing phenylalanine at the C-terminal end of insulin B chain. On the other hand, some proteinases which possessed the ability to attack the peptide bond containing phenylalanine at the C-terminal end of insulin B chain did show a high order of milk-clotting activity, but others showing the same substrate specificity on insulin B chain did show hardly any milk-clotting activity. Blood coagulation was not observed with the other proteinases except thrombin and trypsin. The latter two proteinases possessed the activity to split the peptide bond containing lysine at the C-terminal end of insulin B chain. However, the other proteinases which were found to attack not only the C-terminal peptide bond containing lysine but also the other peptide bonds of insulin B chain did not show any thrombinlike activity. From the results obtained in this experiment, it was concluded that either milk-clotting or bloodcoagulating activities of various proteinases were not always correlated with their substrate specificities on the insulin B chain.

View full abstract