Attempts were made to induce auxotrophic mutants from Candida yeasts by ultraviolet light or ethyl met hanesulfonic acid. Among Candida species tested, C. pelliculosa and C. guilliermondii var. membranaefaciens showed higher mutation rate than haploid strain of S. cerevisiae. More than 80% of the auxotrophic mutants of C. guilliermondii var. membranae-faciens were characterized to be amino acid-less, whereas a quarter of C. pelliculosa mutant was nucleic acid base-less. Accumulation of L-threonine by auxotrophic mutants derived from C. guilliermondii var, membranaefaciens by UV-irradiation was studied. One of the isoleucine auxotrophs, strain 150_-4, accumulated 1.8mg L-threonine per ml of cane molasses medium, while a tryptophan and isoleucine double auxotroph, strain P120_-1, accumulated 2.0mg per ml of the same medium. Enhancement of threonine accumulation was accom-plished by methionine auxotrophs derived from strain P120_-1. About 4mg/ml of L-threonine were accumulated by one of the triple auxotrophs (try^- ileu^- met^-), strain MB_-21, after 4 days culture in 25% cane molasses medium supplemented with 1.5% urea, 10^-3M L-isoleucine, 10^-4M L-methionine and 10^-3M anthranilic acid.

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(+)-Desthiobiotin (IIa) was prepared from D-glucose via several derivatives of azido-sugars. The fourth and the fifth carbons of D-glucose were changed into two asymmetric carbons of IIa through the reaction.

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Coryn. hydrocarboclastus S10B1 could produce a good deal of α-KG, L-glutamate and DL-alanine from n-alkanes in a thiamine-limited medium supplemented with ferrous ion. The replacement of substrate by sugars such as glucose not only decreased the yields, but also reversed the order of the yields among three products. This phenomenon was explained from a metabolic pathway in relation to the role of thiamine. Slow oxygen uptakes of pyruvate and α-KG with thiamine-deficient cells supported the presumption that thiamine limitation resulted in deficiency of a cofactor in the enzymatic oxidation of pyruvate and α-KG. Activities of terminal enzymes in the synthesis of L-glutamate and DL-alanine were determined and discussed. Three intermediates were detected in the culture broth.

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Structural elucidation of the antibiotics bundlin A and B have been accomplished by chemical and spectral results together with three dimensional X-ray structure analysis. The structures of bundlins were consisted of seventeen membered carbon skeleton fused with a six membered lactone system and a pyruvamide side chain.

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Autoxidized lipids have been reported to be toxic. But which compound of autoxidized lipids, hydroperoxides or their secondary products, is really toxic seems to be not still clear. Autoxidized linoleic acid was fractionated by column chromatography and thin-layer chromatography (TLC). The purity of linoleic acid hydroperoxide (LAHPO) was confirmed by TLC and polarography.
The effect of purified hydroperoxide and the secondary products on the growth of Escherichia coli was tested at the beginning and after 2 hr of incubation. LAHPO at 10^-3M concentration showed complete inhibition, when added at the initial stage or at the early log phase. The secondary products at about 0.035% concentration when added at the beginning of incubation showed complete inhibition, but when added at the early log phase they showed no inhibitory effect.
The inhibitory effect of LAHPO was partially retared by the addition of antioxidants, but the inhibitory effect of the secondary products could not be retarded by such com-pounds. These results show that the inhibition mechanism by LAHPO may be of radical type whereas the inhibitory effect of the secondary products may be of different mechanism.

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It has been demonstrated that the microsomal preparations from Hansenula ciferri condense palmitoyl-CoA and serine, producing dihydrosphingosine and sphingosine in the presence of NADPH whereas ketodihydrosphingosine and ketosphingosine in the absence of NADPH. The present paper describes experiments which indicate that the enzymatic condensation of palmitoyl-CoA with serine in the particulate fraction of rat liver produces dihydrosphingosine and sphingosine in the presence of NADPH, but ketodihydrosphingosine and sphingosine in the absence of NADPH. The findings suggest that an alternative route, isomerization of ketodihydrosphingosine, may exist in the animal tissue regarding the formation of sphingosine.

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Two pteridine derivatives (Compound I and II) have been isolated from the synthetic culture fluid on which Serratia indica was grown. Compound I isolated as pale yellow spiny crystals has_??_strong growth-promoting activity for Crithidia fasciculata and was identified as 2-amino-4-hydroxy-6-(L-threo-l', 2', 3'-trihydroxypropyl) pteridine (i. e., L-threo-neopterin) by elemental analysis, by its ultraviolet and infrared absorption spectra, by its fluorescence and excitation spectra, specific rotation, by oxidative degradation study with permanganate and by paper-chromatographic comparison with synthetic L-threo-neopterin. Compound II was identified as 2-amino-4, 7-dihydroxypteridine (i. e., isoxanthopterin) by comparison of its ultraviolet absorption spectra, fluorescence and excitation spectra and by paper-chromatographic behaviours with those of the authentic specimen. The biosynthesis of these pteridines by cell-free extracts of S. indica was also discussed.

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New eleven S-alkyl-2-methyl-DL-cysteines (V) were synthesized. Alkyl groups are as follows: methyl, ethyl, n-propyl, isopropyl, alkyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-amyl and isoamyl. 5-Alkylthiomethyl-5-methylhydantoins (IV), the synthetic intermediates, which were prepared from alkylthiopropanones (III) by Bucherer's method are also new compounds. Alkyl groups are the same as described above. Chlorine containing two hyd-antoins (IVc, IVd) were also preparared.

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An extracellular ribonuclease of Rhodotorula glutinis was purified about 50-fold from the culture broth, by a procedure involving ammonium sulfate fractionation, DEAE-Sephadex column chromatography, acetone fractionation and Sephadex G-100 gel filtration. The purified enzyme was homogeneous when examined by the ultracentrifuge and disc electro-phoresis. The molecular weight was calculated to be 58, 900 and 56, 000 by the sediment-ation-diffusion method and the sedimentation equilibrium method, respectively.

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Changes in the content of amino acid-sugar compounds with natural ageing of flue-cured leaf tobaccos were followed during a period of four years. The content of 1-deoxy-1-prolino-fructose, the most prominent component of the amino acid-sugar compounds in the tobacco, increased in the initial period of the storage and then turned to decreasing. Most of the other amino acid-sugar compounds also showed similar changes in content except for glutamine-fructose compound which only decreased throughout the storage period. These changes indicated the possible progress of Maillard type reactions during natural ageing of leaf tobaccos.

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Iodochlorination of DL(346/5)⁶⁾-diastereomer of 3, 4, 5, 6-tetrachlorocyclohexene (γ-BTC) afforded two diastereomers of 6-iodo-1, 2, 3, 4, 5-pentachlorocyclohexane.⁶⁾ The 220 MHz spectra were used to assign the configurations of these compounds. Another synthesis of a third diastereomer of the iodine compound was described, which confirmed its configuration.

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A screening for antibacterial antibiotics was carried out with psychrophilic microorgan-isms. The most active microorganism, a soil actinomycete, was selected and characterized to be a facultative psychrophile, Streptomyces sp. No. 81. This strain was found to produce antibiotic (s) in the culture fluid only at low temperature cultivation below 20°C but not at moderate temperature. Mycelial growth at low temperature seemed to be indispensable for the antibiotic production. The antibiotic produced by Streptomyces sp. No. 81 was isolated and characterized. It appeared that the antibiotic had the selective toxicity against several Gram-positive bacteria. From the comparative studies with several known antibi-otics, the antibiotic appears to be a new compound derived from the new metabolic routes involving temperature-sensitive mechanisms.

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Several well-known proteinases (pepsin, α-chymotrypsin, papain and trypsin) and various microbial proteases available in Japan were investigated for pH dependence of their plastein-synthetic activities and also for that of their protein-hydrolytic activities. The optimum pH-values for synthesizing plasteins from a peptic hydrolyzate of soy protein existed in the range of pH 3_??_7, whereas those for hydrolyzing a denatured soy protein covered the range of pH 2_??_11. Based on ΔpH (optimum pH-value in synthesis minus that in hydrolysis), the enzymes used were classified into three types: pepsin type (ΔpH>0), chymotrypsin type (ΔpH<0) and papain type (ΔpH=0), with the exception of trypsin (not plastein-productive at any pH). Higher plastein yields were given by pepsin, α-chymo-trypsin and papain as the well-known proteinases, and by Molsin (acid protease produced by Aspergillus saitoi), Coronase (neutral protease produced by a certain Rhizopus), Bioprase (alkaline protease produced by Bacillus subtilis), etc. as the available microbial proteases.
Instead of a peptic hydrolyzate, hydrolyzates obtained by treatment with microbial proteases were used as the substrates of the plastein reaction. For example, by incubating a soy protein concentrate (1% aqueous solution) with Molsin at pH 2.8, a hydrolyzate was obtained in which 10% trichloroacetic acid insoluble fraction amounted to approximately 30% on dry basis. Subsequently, when the hydrolyzate was concentrated to 40% and incubated with Molsin at pH 6 for 72 hr, the yield of the trichloroacetic acid insoluble fraction increased to approximately 80% on dry basis.

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During the growth of Arthrobacter paraffineus KY 7134 on n-paraffin as the sole source of carbon, it was found that two sorts of crystalline pigments, yellow and deep-red, were accumulated in the culture medium. These were isolated and identified respectively as 1, 6-dihydroxyphenazine (DHP) and 1, 6-dihydroxyphenazine-5, 10-di-N-oxide (DHPO).
For the production of these pigments by this microorganism, n-paraffin, particularly n-octadecane was the most preferable carbon source. Furthermore, controlling the medium-pH in the neutral range and keeping the aeration of the higher level in the growing phase were essential for this fermentation.

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This study investigates the fate of ¹⁴C labelled 2, 4-D used as_??_trigger compound during callus induction (dedifferentiation). It also traces the special relationship of 2, 4-D with some high molecular weight components in vivo, in which 2, 4-D-2-¹⁴C was found com-bined with high molecular weight component-fractions. Nucleic acids showed very low radioactivities, based on MAK column chromatography and centrifugal profiles from sucrose density gradient treatments, but there was no specificity in this radioactive incorpo-ration. Centrifugal profiles and Pronase treatment indicate that protein combines with 2, 4-D-2-¹⁴C. These results support the claim for a model of auxin-induced derepression, in which auxin interacts with its binding protein.

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The additional new metabolites, named phyllostine (II) and 3-chloro-2, 5-dihydroxybenzyl alcohol (III) from the cultural filtrates of Phyllosticta sp. have been isolated. The chemical structure of II have been established by spectral studies and chemical conversion from the known I, and the chlorine-containing metabolite (III) by spectral and synthetic studies. The metabolite (II) exhibits the similar phytotoxic effects as I, but the metabolite III does less phytotoxicity than I and II on the leaf test.

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The insect feeding inhibitory activity of terpenoids in plants was surveyed and it was found that two sesquiterpenoids, pinguison and absinthin have the activity against Spodop-tera littoralis Boisd. and the effectiveness of absinthin vary with the age or the rearing conditions of the insect.

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N, N'-Bis-(4-quinaldino)-α, ω-diaminoalkanes dihydrochloride are found to be highly active (in vitro) against S. aureus, E. coli and M. tuberculosis (H37Rv strain) and the corre-sponding 4-quinazolino compounds inactive.

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Isopentyl isovalerate and anisic acid were first isolated and identified from the Japanese peppermint oil. The former compound possesses characteristic apple-like oder. α-Bour-bonene, menthofurolactone, and β-caryophyllene epoxide were also isolated and identified from the oil of Shubi, a newly registered Japanese peppermint.

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