Glucose isomerase was purified by means of acetone fractionation, DEAE-cellulose column chromatography, DEAE-Sephadex column chromatography and crystallization. The purified enzyme appeared to be homogeneous on ultracentrifugation and electrophoresis. The sedimentation coefficient, s_{20, w}, the diffusion coefficient, D_{20, w}, and partial specific volume of the enzyme were 8.0S, 4×10^-7cm²/sec and 0.69ml/g, respectively. The molecular weight of the enzyme was estimated to be 157, 000 from the sedimentation and diffusion measurements. The crystalline glucose isomerase contained cobalt and magnesium ions. The properties of the enzyme were also studied.

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Yeast isoamylase was highly purified by means of salting-out with ammonium sulfate, chromatography on DEAE-cellulose, and gel filtration on Sephadex G-100. More than 200-fold purification was achieved through these procedures from crude yeast extract. While the purified enzyme did not attack α-1, 6-glucosidic linkages in panose, isopanose (6-malto-sylglucose), branched triose (4, 6-diglucosylglucose), and isomaltosylmaltose (6³-α-glucosylmalto-triose), it acted on α, β-limit dextrin (DP 9.6) to liberate glucose as well as maltose and higher oligosaccharides. Substrate specificity of the yeast isoamylase was discussed in comparison with that of plant and bacterial isoamylases (R-enzyme and pullulanase), and the mechanism of debranching of glycogen by yeast enzymes was also discussed.

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The fine structure of phage HM 2 (group I) active on Clostridium saccharoperbutylacetonicum was studied by an electron microscopy with a negative-staining technique, and compared with those of more conventional types, phages HM 3 (group II) and HM 7 (group III), whose tails were clearly observed by a shadow-casting technique. This study revealed that phage HM 2 had an intricate tail which was not observed by a shadow-casting technique.
Phage HM 2 has an icosahedral head about 450Å in diameter and a non-contractile tail about 300Å long. The distal 130Å of the tail axis has a width of 80Å which is wider than the upper portion of the tail (50 to 60Å). The distal enlargement is not seen in the hollow tail. Twelve fibrous-shaped appendages are attached symmetrically at the upper portion of tail axis and extend toward the distal base of the tail. Their length is a little shorter than 300Å. They combine with divalent cations in the phage dilution medium, and also adsorb the host cell debris.
Phage HM 3 has an icosahedral head about 770Å in diameter and a tail about 1000Å long and 150Å wide with contractile sheath. Phage HM 7 has an icosahedral head about 750Å in diameter and a long non-contractile tail about 2000Å long and about 120Å wide with forked tip.
The structure of the tail of phage HM 2 is quite different from those of phages HM 3 and HM 7 hitherto described and those of the various phages of other bacteria.

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Participation of RNase I in the growth of phage on infection with bacteriophage MS2 was studied.
Some strains of uracil-requiring E. coli were isolated, grown in MS broth, and transferred to a minimal medium to exhaust the pool of nucleotides. The phage was then added to the cells grown in uracil-deficient medium. The growth of phage was observed to occur at the burst size of two hundreds in strains of E. coli K12S (F^-) U^- and C600 (F^-) U^-, which possessed RNase I, but not in strains, A19 (Hfr) U^- and Q13 (Hfr) U^-, which lacked RNase I.
A marked increase in acid-soluble fraction was observed with E. coli K12S (F⁺) U^- and C600 (F⁺) U^-, whereas the increase was little with E. coli A10 (Hfr) U^- and Q13 (Hfr) U^- Conditions for the growth of phage in uracil-deficient medium were investigated and the effect of antibiotics were also investigated.

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α-Pinene, terpinolene, ô-elemene, α-copaene, α-and β-humulene, β-sesquiphellandrene, γ-cadinene, acetate of p-menthen-l-ol-9 and acetate of p-menthadien-1, 8 (10)-ol-9 were newly identified as the volatile constituents of peel oil from C. Unshiu. Aroma characteristics of C. Unshiu are discussed on the basis of quantitative analysis.
Comparison of aroma patterns of peel oil among various citrus fruits was also carried out with head space analysis.

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Methylisothiocyanate reacts with the amino group of amino acid in alkaline solution to give methylthiocarbamyl amino acid. This is converted to the methylthiohydantoin derivative (MTH-amino acid) by subsequent acidification.
Gas chromatographical identification of 20 amino acids were examined by making MTH-amino acids. Among them, ten amino acids (glycine, alanine, valine, leucine, iso-leucine, proline, methionine, phenylalanine, serine and threonine) were successfully identified. Aspartic acid and glutamic acid could be identified as the methyl esters of the MTH-amino acids.

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Forty five organisms selected from 12 genera of bacteria listed in Bergey's Manual (1957) were subjected to numerical analysis based on the two different similarity matrices representing the overall similarities of phenetic characters and the similarities of guanine+cytosine contents of DNA molecules.
The classification based on the similarities of GC-contents obtained “lump” taxa, in contrast with the classification based on the overall similarities of phenetic characters.
Rationale of the former classification is briefly discussed.

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Growth of various microorganisms in media containing high concentrations of glycine or D-amino acids was examined. Susceptibilities to glycine or D-amino acids differed among microorganisms, and the differences in susceptibility have no direct relation with Gram staining, morphological forms, and aerobic or anaerobic nature of the organisms. Certain glycine-resistant bacteria tested, which included Bacillus cereus, Staphylococcus aureus and Serratia marcescens, exhibited relatively high oxidative activities towards glycine. The inhibition of the growth of Escherichia coli by either glycine or D-amino acids, which included D-threonine, D-alanine and D-lysine, was reversed by L-alanine, partialy by L-serine, and not by L-lysine or L-threonine. These results suggest that the growth inhibi-tion of microorganisms by D-amino acids was similar to that by glycine. The incorpora-tion of L-alanine into E. coli cells which were preincubated with glycine was less than those of preincubated without glycine. Particularly, the incorporation into the cell wall fraction was most susceptible to glycine. An additive effect of penicillin and glycine was observed in the inhibition of cell wall biosynthesis as determined by the intracellular accumulation of N-acetylamino sugar compounds.

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1. Sixty strains of 1, 2-propanediol-utilizing microorganisms were isolated from soil.
2. One strain, PG-21-1, well assimilated ethanol, 1, 2-propanediol, 1, 3-propanediol and 1, 3-butanediol, and yield acids from all of them. This strain was identified to Arthrobacter oxydans.
3. This strain produced lactic acid from 1, 2-propanediol and β-hydroxybutyric acid from 1, 3-butanediol.
4. Urea and pH of medium were very important factors to promote the yield of lactic acid.
5. The residual 1, 2-propanediol purified from culture broth was optically active.

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A screening for antiviral antibiotics was carried out using paper-disc agar-diffusion method. The microorganisms tested were unidentified soil fungi and the type cultures of our laboratory including actinomycetes, fungi, yeasts and bacteria. Mycelia or cells were extracted with acetone and the antiviral activity of the acetone extracts was determined. The extracts of actinomycetes mycelia showed the highest frequency of the appearance of antiviral activity against Newcastle disease virus. The frequencies of the appearance of antiviral activity in fungal and bacterial type cultures were the same degree and that of yeasts was low. Antiviral activity of the principles thus obtained was studied by microscopic observation in tube cultures using HeLa cells as a host.

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A new biologically active substance named fragin was isolated from cultured broth of a bacterial strain, which was identified as Pseudomonas fragi based on taxonomic study. Isolation, characterization and biological activities are described in detail.

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During the course of studies on the oxidative metabolism of D-sorbitol by acetic acid bacteria, it was found that D-sorbitol was almost quantitatively converted to 5-keto-D-fructose via L-sorbose by a certain strain of Gluconobacter suboxydans. In addition to 5-keto-D-fructose, three γ-pyrone compounds, kojic acid, 5-oxymaltol, and 3-oxykojic acid, 2-keto-L-gulonate, and several organic acids such as succinic, glycolic, and glyceric acids were confirmed in the culture filtrate of this bacterium.

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1) The most suitable carbon source for 5-ketofructose fermentation by Gluconobacter suboxydans Strain 1 was confirmed to be D-sorbitol or L-sorbose using growing and resting cells. D-Fructose had little effect on the formation of this dicarbonylhexose.
2) The optimal pH for the formation from L-sorbose by intact cells was found to be at 4.2.
3) The activity of the pentose phosphate cycle in the resting cells was calculated as 13_??_17μatoms/hr/mg of dry cells by the use of the manometric techniques.
4) There was no strain tested so far which could accumulate a large amount of 5-keto-D-fructose from D-sorbitol except this bacterium.
5) The experimental results shown in this paper makes the prediction that a certain dehydrogenating system of L-sorbose is functional in the organism, and the metabolic pathways of D-sorbitol via L-sorbose and 5-keto-D-fructose is proposed.

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A bacterium isolated in our laboratory, Arthrobacter paraffineus KY4303. when grown on n-paraffin as the sole source of carbon, produced anthrone-positive lipid in the emulsion layer (holding bacterial cells, lipids and n-paraffin remained) of the culture medium. This was isolated and identified as α-branched-β-hydroxy fatty acid trehalose ester.
The addition of penicillin to the growing culture caused a significant suppression of trehalose lipid formation and led consequently to the accumulation of both the precursors, α, α-trehalose and α-branched-β-hydroxy fatty acid, in the culture medium.
The formation of trehalose lipid was also observed in other bacteria which can utilize n-paraffin as the sole source of carbon. In addition, a possible role of this trehalose lipid in the utilization of n-paraffin by these bacteria was discussed.

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Autolysis of the cells of Str. cremoris and L. helveticus, both of which were harvested from the liquid culture after 48 hr cultivation, were investigated by shaking these cells suspended in M/15 phosphate buffer, under starvation condition, pH 7.0, at 35°C for 10 days. Both amounts of nitrogen and DNA substance released from the cells of Str. cremoris were about 20%o after 3 days incubation but the amounts of the nitrogen and DNA substance released from the cells of L. helveticus were about 20% and 60%, respectively, after 3 days incubation. Those values obtained from two kinds of bacteria became almost constant after 10 days incubation.
Proteolytic activities in supernatants prepared from these two cell suspensions were detected after 3 days incubation and the maximum activities were attained after 6 days incubation.
The activities of lactic dehydrogenase released from Str. cremoris and L. helveticus during cultivation in skim milk were detected even after one day cultivation.
These indicate that autolysis of both kinds of lactic acid bacteria occurred only after one day cultivation in milk even under condition rich in nutrients, and intracellular protease, which could hydrolyze milk protein, α_s casein, was released.

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Cholesterol decomposing ability of 1589 microbial strains was examined. Two hundreds and thirty six strains from actinomycetes, bacteria, molds, and yeasts were found capable of oxidizing cholesterol into cholestenone. Cholesta-l, 4-dien-3-one was produced by 5 strains of Streptomyces. The complete decomposition of cholesterol molecule was observed in the genera: Arthrobacter, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, Mycobacterium, Nocardia, Protaminobacter, Serratia, and Streptomyces. α, α'-Dipyridyl and arsenite inhibited decomposing enzymes giving rise to cholestenone, cholesta-1, 4-dien-3-one, and an intermediate probably devoid of the sterol side chain.

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Selective cleavage of the side chains of various sterols at C-17, giving rise to androsta-l, 4-diene-3, 17-dione (ADD), occurred in the presence of α, α'-dipyridyl by microorganisms of the following genera: Arthrobacter, Bacillus, Brevibacterium, Corynebacterium, Microbacterium, Mycobacterium, Nocardia, Protaminobacter, Serratia, and Streptomyees. The degradation pathway of cholesterol, for example, was shown as follows:
cholesterol→cholest-4-en-3-one→cholesta-1, 4-dien-3-one
↓t↓
andros-4-ene-3, 17-dione→ADD
Other sterols such as campesterol, β-sitosterol, stigmasterol and 7-dehydrocholesterol were degraded by the same sequence. The pathway exemplified in cholesterol is considered to be the general degradation pathway of sterols by their decomposing microorganisms.
It was further demonstrated that ADD thus formed from sterols was converted into 3-hydroxy-9, 10-secoandrosta-1, 3, 5(10)-triene-9, 17-dione.

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