An investigation has been made here into the masking effect of an extract of Lycium chinense-the so-called “Kuko”-upon the qualitative thiamine reaction. And the fact, that the factor in the extract responsible for thiamine-decomposition is not attributable to an enzyme, has been proved by the following: (a) The factor was thermostable, for, even when the extract was boiled about an hour, its thiamine-decomposing ability was not decreased. (b) Thiamine-decomposition was completed in a moment and did not increase as time passed on.
When cysteine or ascorbic acid was added to a thiamine solution, the diazo reaction of which was masked by adding the extract to it, the reaction was normally regained.
The mother substance which has relations with the masking effect was adsorbed into the lead subacetate, anhydrous. When one-dimensional ascending paper chromatography was carried out by using n-butanol-acetic acid and water (2:1:1), Rf value of the substance showed 0.55. Being a substance of yellowish brown-needle-like crystals while soaked in dehydrated ethanol, it turned completely into a brownish resinoid substance the moment ethanol was removed. One mg of the substance could mask 3μg or more of thiamine under the experimental condition given by the author.

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A newly isolated strain, which belongs to Bacillus, was mutated to adenine dependency by treatment with the mutagen, N-methyl-N'-nitro-N-nitrosoguanidine. The adeninerequiring strains, as expected, accumulated inosine.
Cultural conditions for inosine synthesis de novo and the pathway of inosine formation in the mutated strain were investigated. 1) NH₄Cl was the preferred nitrogen source. Addition of MnCl₂•4H₂O was effective for the accumulation of inosine. 2) In this fermentation process, hypoxanthine was formed first, and, after that, inosine was accumulated in the medium. When hypoxanthine was added in the medium, the formation of inosine greatly increased, and, after 90 hours, almost all the hypoxanthine added was converted to inosine. 3) Hypoxanthine-8-C¹⁴ was converted to labeled inosine by growing cells, but not converted to cellular RNA. Labeled inosine was formed from hypoxanthine-8-C¹⁴ and ribose-1-phosphate by intact cells or cell-free extract.
It is presumed that the route of inosine accumulation in the adenine-auxotrophic mutant, Bacillus sp. No. 226, is as follows.
de novo synthesis→5'-IMP→hypoxanthine→inosine
_??_
inosine phosphorylase

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Much research on the determination of vitamin B₆ has been conducted by many investigators with the method of bioassay or with several physical and chemical methods. But the disadvantages of the complicateness in procedure and the long time requirement for the treatment have still remained in these methods. It was assumed that the estimation of pyridoxine (PIN) can be successful by the direct titration with bromine or N-bromo succinimde solution, since the reagents can brominated PIN into 3, 6-dibromo pyridoxine quantitatively. However, the estimation of PIN by the titration with bromine solution, using starch as indicator, had failed because the end point could not be sharply decided.
A good result was obtained when a potentiometer (platinum-calomel pair as electrode) was used as a detector for the end point. The method gave the following results : At the end point, the difference of potential caused by the addition of one drop of _N/50 bromine or _N/100 N-bromo succinimide solution was more than 70mV, therefore the observation of the end point could be done accurately and without difficulty. The standard deviations were within 1.5% when bromine solution and with N-bromo succinimide solution was used respectively. But N-bromo succinimide reagent was rather suitable, because it was more stable than bromine solution. The method was effective to PIN-pure solution which was in higher cincentration than 2.5μg per ml. The application of the method to the estimation of pyridoxal was possible with good result.

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To remove cationic radionuclides from milk by the use of ion-exchange technique, the optimum ratio of major cation (Ca, Mg, Na and K) on strong sulfonic acid ion-exchange resin, Amberlite IR-120, was determined so as to keep the change in the cationic composition in the milk as small as possible. The suitable salt composition in the solution, which was used to regenerate the resin, was as follows; Ca 0.67, Mg 0. 23, Na 0. 13 and K 0.77 equivalent/l of the solution. In order to minimize the change in miIk quality at the early stage of ion-exchange process, three to ten times milk against resin by volume was used. No difference in total solids, fat, protein, lactose and ash contents between non-treated and the treated milk was observed, though trace amounts of these components were adsorbed on the surface of the resin particles. The increases in Ca, Mg, K and Na contents in the treated milk were -7.5%, +5.7%, +18.4% and -4.1%, respectively, compared with original milk. Free calcium ion was easily exchanged by the resin. The treated milk, therefore, showed lower curd-tension value and longer rennet coagulation time compared with non-treated milk. Lower curd-tension value was recovered by adding calcium chloride.

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The effect of the pH of milk, temperature, flow rate, and volumes of milk on the removal of radioactive strontium and cesium from milk was studied. The milk was labelled with ⁸⁵Sr or ¹³⁴Cs (1μc/l of milk) in vitro and was passed through a column containing Amberlite IR-120 (Ca: Mg: K: Na) resins as previously reported (1). The amount of ⁸⁵Sr removed from the first 5 resin bed volume (rbv) was increased from 59.1 to 93.7%, as the milk was acidified from pH 6.6 to pH 5.45, contrasting with ¹³⁴Cs which was not increased. When milk was passed through at normal pH (6.65), about 7% more removal for ⁸⁵Sr was obtained at 30.0°C than at 12.5°C. But no increase was obtained by heating the milk for the removal of ¹³⁴Cs and ⁸⁵Sr (pH 5.45). The removal of ⁸⁵Sr from milk (pH 6.60) decreased from 65.7 to 60.8%, as the flow rate was increased from 0.083 to 0.333 rbv per minute. The removal up to 50 rbv at a flow rate of 0.167 rbv per minute were 55.9% for ⁸⁵Sr (at pH 6.60), 88.0% for ⁸⁵Sr (at pH 5.45) and 45.7% for ¹³⁴Cs (at pH 6.60).

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To remove anionic radionuclide, ¹³¹I, from milk by the use of ion-exchange technique, the optimum ratio of major anions (Cl^-, PO₄^3-, C₆H₅O₇^3-) on strong base quaternary ammonium type ion-exchange resin, Amberlite IRA-410, was determined so as to keep the anionic compositions in the milk as small as possible. The suitable salt composition in the solution, which was used to regenerate the resin, was as follows; Cl^- 0.09, C₆H₅O₇^3- 0.83 and PO₄^3- 0.08 equivalent/l of the resin. No difference in total solids, fat, protein, lactose and ash contents between not-treated milk and the treated milk was observed, though trace amounts of these components were adsorbed on the surface of the resin particles. The decreases in chlorine, citrate and phosphate contents in the treated milk were 8.8%, 1.4% and 11.6%, respectively. Lower curd-tension value of treated milk compared with non-treated milk by pH increase was recovered by pH adjustment. The iodine removal by the composite salt form resin was above 99% for the 200 times milk against resin.

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Effects of heating on soybean meal proteins were examinded by means of gel-filtration on Sephadex G-200, acryl amide gel electrophoresis and observation under electron microscope. Whole water extract, acid-precipitated protein and calcium-precipitated protein solutions were prepared and submitted to gel-filtration and acryl amide gel electrophoresis. In the case of Sephadex column chromatography, whole water extract was separated into five fractions, being estimated by 280mμ absorption. In chromatograms of acid-or calciumprecipitated protein, the later eluted fractions decreased or almost disappeared. By heating of these solutions including whole water extract, the fractions except the first eluted main fraction were much reduced or disappeared, perhaps transferring to the first one by association. On acryl amide gel electrophoretical patterns, it was recognized that some fast-moving bands faded away after heating. By electron microscopy of whole water extract in the presence of calcium chloride, numerous spheres of about 0.05μ were observed scattering all over the field. The spheres aggregated randomly to irregular blocks by heating.
It seems to be concluded that heating soybean protein solutions at 100°C for 15 min gives the trend to associate as previously indicated by ultracentrifugation analysis.

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This thesis aims at making inquiries into the distribution of thiamine-decomposing factors in mushrooms of 190 species or so belonging to Agaricales, Aphyllophorales, Gasteromycetes and Ascomycetes. The author has obtained some evidences which will suggest that the thiamine-decomposing enzyme called “thiaminase” is widely distributed in mushrooms. And some of these mushrooms could decompose 300_??_900μg of thiamine per 0.1g of their dry matters under an experimental condition given by the author. In result, he has come to find that these thiamine-decomposing factors are strong, particularly in strains such as Russulaceae, Strophariaceae, Cortinariaceae and Tricholomataceae.

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