Octahydropiericidin A (HPA) was degraded to C₁₁-, C₁₂- and C₁₄-dioic and C₁₃-hydroxy acids, via C₁₈-keto acid, to which structures XI, X, VIII and VII were proposed respectively through analyses of their NMR and mass spectra. Consideration of these results together with the NMR spectrum of piericidin A (PA) and other chemical evidences led to assign structures IIa and IVa to PA and HPA, respectively.

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To confirm the structure of a polysubstituted pyridine ring contained in piericidin A (I), a model compound, 4-hydroxy-6-hydroxymethyl-2, 3-dimethoxypiridine (IV) was syn-thesized starting from 2-bromo-6-hydroxymethyl-3-methoxy-4-oxo-(4H)-pyran (V). Ultra-violet spectra of octahydropiericidin A (II) and Acid II (III) derived from I were almost identical with that of IV and the pyridine ring in I was finally proved to be 4-hydroxy-2, 3-dimethoxy-5-methylpyridine.

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Mass spectra of C₁₁-dioic, C₁₂-dioic and C₁₃-keto acids methyl esters, which are the degradation products of octahydropiericidin A (II), are consistent with the assigned structures, IX, VI and X, respectively. Confirmation for the side chain skeleton of piericidin A (I) is successfully accomplished through mass spectrometry on some derivatives of II.

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1) Many strains of microorganisms capable of producing L-glutamic acid from DL-hydan-toin-5-propionic acid were found.
Among these, the active strains were Pseudo-monas dacunhae IAM 1199, Pseudomonas incognita IPR. AHH 38, Pseudomons sp. No. 42 ATCC 15447, Micrococcus subfavus FLUEGE IFO 3026, Aerobacter cloacae T-14, Aeobacter aerogenes T-13, Escherichia intermedia IPR. S-51, Achromobacter pestifer No. 80. ATCC 15445, Achromobocter cycloclastes ATCC 15446, and Bacillus brevis ATCC 8185, and the highest was Bacillus brevis ATCC 8185.
2) It was newly found that these bacteria produced exclusively L-form of glutamic acid from both D- and L-form of hydantoin-5-pro-picnic acid.
3) The optimal condions for producing L-glutamic acid by Bacillus brevis ATCC 8185 were as follows, the reaction pH was 9.0 and the temperature was 42°C. Under these adequate conditions using reaction mixture containing 1.0% of DL-hydantoin-5-propionic acid, intact cells of this strain converted 900 of the DL-acid to L-glutamic acid.
4) Addition of DL-hydantoin-5-propionic acid to the preculture medium is necessary to obtain the highly active cells to produce L-glutamic acid.
5) A pathway of producing L-glutamic acid from D-hydantoin-5-propionic acid was also discussed. The assumptive pathway is D-HPA→_chemicalL-HPA→_enzymaticL-glutamic acid.

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Taxonomical characteristics of a thermophilic streptomycete which had been reported to produce a relatively thermostable proteinase were examined, and it was found to belong to a variety of Streptomyces rectus for which the name Streptomyces rectus var. proteolyticus was suggested. Some cultural conditions for proteinase formation by this strain were investigated. The formation of proteinase was greatly stimulated by the addition of Mn and affected by the composition of medium. The proteinase formation occurred during the stationary phase of growth at 50°C, while intracellular peptidase was formed in early logarithmic phase. No presence of precursor of the proteinase was suggested.

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Decreases of respiration rates in the presence of excess sugars, substrates and non-substrates, were investigated kinetically on the cell free preparation of a Pseudomonas. The schemes of enzyme inhibition which include successive inactive complexes of one mole of enzyme and two and three moles of substrate or one mole of enzyme and one and two moles of inhibitor were shown to fit the experimental results. Water concentrations were not enough to explain the different inhibitory properties of sugars.

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A method of determining oxygen transfer rate in shaken flasks was established. By analyzing the partial pressure of gas-phase oxygen in flasks, oxygen transfer coefficient of cotton plugs k, overall oxygen transfer coeffi-cient across gas-liquid interface KLa and respi-ration rate KrM could be evaluated. Dissolved oxygen measurement was not necessary. This method could be applied to both sulfite solu-tion and biological systems. In the biological systems, especially, the same experiment gave the values of KLa and KrM simultaneously. This method of KrM determination has an advantage of performing in the more ana-logous state to the actual fermentation per-formances than in polarographic procedure. Based on this method, it became evident that oxygen transfer in shaken flasks should be recognized with respect to the overall oxygen transfer coefficient including the diffusibility of both cotton plugs and gas-liquid interface.

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(±) Hydroxytremetone (III) has been synthesized from 2-(α-hydoxyisopropyl)-6-hydroxy-coumaran (V b) via its 0-acetate V c by dehydration with phosphorus tribromide in pyridine solution, followed by acylation with a mixture of trifluoroacetic anhydride and acetic acid. Isohydroxytremetone (IX b) was also synthesized.

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The biotin-vitamer was isolated in crystalline form from culture filtrate of Bacillus sphaericus. The crystalline vitamer identified as desthiobiotin.

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The hitherto unknown cyanoacetates of menthol isomers, i.e., (±)-menthyl, (±)- and (+)-neomenthyl, and (±)- and (+)-isomenthyl cyanoacetate, have been prepared. It has been proved to be possible to isolate effectively pure (±)-menthol from optically inactive mixture of isomers through the cyanoacetate, followed by saponification.

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A new imidazole compound was isolated as crystalline form from the reaction mixture of glucose and ammonia, and identified as 4(5)-(DL-glycero-2, 3-dihydroxypropyl)imidazole. From the results the authors suggested that pentose may be formed in the reaction mixture not by direct fission of C-C bond of glucose but by recombination of glucose fragments, for example, of triose and glycolic aldehyde.
4(5)-[D-(-)-Glycero-2, 3-dihydroxypropyl]imidazole was also newly prepared from D-xylose via 3-deoxy-D-pentosone.

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Two kinds of fluorescent compounds were isolated in crystalline forms, by silica gel column chromatography, from Japanese chestnuts stored in cold. They had bluish violet and greenish blue fluorescence, and were identified as 6, 7-dimethoxycoumarin and scopoletin, respectively.

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An enzyme system which could convert orotic acid to uridine-5'-monophosphate (5'-UMP) was found in cell-free extract of a threonine-requiring auxotroph of Micrococcus glutamicus (Syn. Corynebacterium glutamicum) 534 C_o-147. This reaction required 5-phos-phoribosylpyrophosphate (PRPP) and magnesium ion as essential components. The product of the enzyme reaction was separated by ion exchange resin chromatography and identified to be uridine-5'-monophosphate. From the stoichiometric studies and other characteristics, it became evident that this enzyme reaction proceeded according to the following equation and was assumed to be catalyzed by orotidine-5'-monophosphate pyrophosphorylase and orotidine-5'-monophosphate decarboxylase.
Orotic acid+PRPP→Mg⁺⁺5'-UMP+PPi+C0₂

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