The growth of Bacillus subtilis TR-44, a prototrophic transductant from one of inosine producers, was completely inhibited by 200μg/ml of 5-fluorotryptophan, a tryptophan analogue, and the inhibition was reversed by the addition of L-tryptophan.
Several mutants resistant to 5FT^* produced L-tryptophan in the growing cultures. The best producer, strain FT-39, which was selected on a medium containing 1500μg/ml of 5FT, produced 2g/liter of L-tryptophan, when cultured in a medium containing 8% of glucose but without any tryptophan precursors. In this mutant, anthranilate synthetase, a key enzyme of the tryptophan biosynthesis, had increased over 280-fold, presumably owing to a genetic derepression. From FT-39, mutants resistant to 7000μg/ml of 5FT were derived. Among them, strain FF-25 produced 4g/liter of L-tryptophan, twice as much as did the parental strain. Since this strain produced large amount of L-phenylalanine as well as L-tryptophan, the genetic alteration seemed to be involved in some metabolic regulation of common part of the aromatic amino acid biosynthetic pathway.
Further, some auxotrophs derived from these 5FT resistant mutants produced more L-tryptophan than did the parental strains.
Relationships between the accumulation of L-tryptophan and the regulation mechanisms of the L-tryptophan biosynthesis were discussed.

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Polyauxotrophic mutants of Corynebacterium glutamicum which have additional requirements to L-phenylalanine were derived from L-tyrosine producing strains of phenylalanine auxotrophs, C. glutarnicum KY 9189 and C. glutamicmn KY 10233, and screened for L-tyrosine production. The increase of L-tyrosine production was noted in many auxotrophic mutants derived from both strains. Especially some double auxotrophs which require phenylalanine and purine, phenylalanine and histidine, or phenylalanine and cysteine produced significantly higher amounts of L-tyrosine compared to the parents. A phenylalanine and purine double auxotrophic strain LM-96 produced L-tyrosine at a concentration of 15.1mg per ml in the medium containing 20% sucrose. L-Tyrosine production by the strain decreased at high concentrations of L-phenylalanine.

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p-Fluorophenylalanine (PFP) and m-fluorophenylalanine were the most effective inhibitors on the growth of Corynebacterium glutamicum ATCC 13032 among the analogs of phenylalanine and tyrosine tested. Their inhibitory effects were released by L-phenylalanine, and slightly by L-tyrosine and L-tryptophan. 3-Aminotyrosine (3AT), p-aminophenylalanine, o-fluorophenylalanine, and β-2-thienylalanine were weak inhibitors.
Resistant mutants of C. glutamicum isolated on the medium containing both PFP and 3AT or PFP and L-tyrosine were found to accumulate both L-tyrosine and L-phenylalanine, while resistant mutants isolated on the medium containing only PFP were found to produce only L-phenylalanine. Resistant mutants from other glutamic acid producing bacteria isolated on the medium containing both PFP and 3AT or both PFP and L-tyrosine were found to accumulate L-tyrosine and L-phenylalanine.

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Mutants resistant to various phenylalanine- or tyrosine-analogs were isolated from a phenylalanine auxotroph of orynebacterium glutamicum KY 10233 by treatment with N-methyl-N nitro-N-nitrose guanidine (NTG) and screened for L-tyrosine production. A mutant, 98-Tx-71, which is resistant to 3-aminotyrosine, p-aminophenylalanine, p-fluorophenylalanine, and tyrosine hydroxamate was found to produce L-tyrosine at a concentration of 13.5mg/ml in the cane molasses medium containing 10% of sugar calculated as glucose. A tyrosine-sensitive mutant, pr-20 which was derived from 98-Tx-71 produced L-tyrosine at a concentration of 17.6mg/ml. L-Tyrosine formation in the strain pr-20 was found to be still inhibited by L-phenylalanine though it was not inhibited by L-tyrosine. The L-tyrosine formation in the mutant was repressed neither by L-phenylalanine nor by L-tyrosine.

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A strain of Streptomyces produces a new substance capable of inactivating some amylases. This has not been reported by previous workers.
This amylase inhibitor was purified by means of acetone treatment, active carbon adsorption and column chromatography on DEAE-cellulose.
It was dialyzable through a cellophane membrane and soluble in water and methyl alcohol. The inhibitor had a small molecular weight and was a peptide-like substance. The inhibiting substance was resistant to the temperatures, and acted as inhibitor of glucoamylase, bacterial saccharogenic α-amylase, salivary and pancreatic α-amylases.

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The enzyme showed the optimum pH between 7.5 and 8.0, and the optimum temperature at about 37°C. It was stable over the pH range from 4 to 9 and below 40°C, but completely lost the activity by heating 60°C for 15min. The enzyme was activated by low concentration of calcium ion but inhibited partially by high concentration of calcium ion and by EDTA. With respect to substrate specificity, the enzyme exhibited a high specificity toward triglycerides and hydrolyzed ester bonds of short-carbon chain triglycerides faster than long-carbon chain triglycerides, whereas it catalyzed the hydrolysis of the oils from rice bran, olive and coconut. When 2-oleo-1, 3-distearin was used as substrate, the enzyme was capable of preferentially hydrolyzing fatty acid ester bonds at the 1, 3-position.

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The acceptor specificities of bacterial nucleoside phosphotransferase were further investigated by phosphorylating various kinds of nucleoside analogues. The bacteria belonging to A group(5'-nucleotide former) specifically phosphorylated the primary alcohol at 5'-position of nucleosides and their analogues, such as adenine xyloside, psicofuranine and pseudouridine, while the others belonging to B group (3'(2')-nucleotide former) the secondary alcohol at 3'(2')-position. The phosphorylation at 5'-primary alcohol with the bacteria belonging to A group, however, was prohibited mainly by phosphoryl- or amino-radical at 3'-position, as observed in the case of 3'-nucleotide or amino-nucleoside (or puromycin), depending on the steric conformation around the 3'-position of acceptor. Besides, both types of nucleoside phosphotransferases were also able to phosphorylate nucleoside having a C-C-linkage between base and sugar moieties.

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Ultracentrifugically homogeneous glucomannan acetate derived from konjac mannan was subjected to acetolysis. Besides β-1, 4-linked oligosaccharides composed of D-mannose and/or n-glucose, three oligosaccharides corresponding to the branching point of the polysaccharide were isolated and identified as (1) 3-O-β-D-mannopyranosyl-o-mannose, (2) O-β-D-mannopyranosyl-(1→4)-O-β-D-mannopyranosyl-(1→3)-D-mannose, and (3) O-β-D-mannopyranosyl-(1→3)-O-β-D-mannopyranosyl-(1→4)-D-glucose. The average chain length (CL) was, moreover, determined to be about 46 by methylation analysis. The structural pattern of the glucomannan, including the branching point, is discussed.

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The growth of Brevibacterium flavum No. 2247 A was inhibited by α-amino-β-hydroxy-valeric acid (AHV), and the inhibition was partially reversed by L-isoleucine.
AHV resistant strain ARI-129, which was isolated on a medium supplemented with 2mg/ml of AHV, produced 11g/liter of L-isoleucine.
No difference was observed in threonine dehydratase between No. 2247 A and ARI-129. Homoserine dehydrogenase from ARI-129 was insensitive to the feedback inhibition by L-isoleucine and L-threonine.
O-Methyl-L-threonine resistant mutant, strain AORI-126, which was derived from ARI-129, produced 14.5g/liter of L-isoleucine. Specific activity of threonine dehydratase from AORI-126 increased about two-fold higher than those from No. 2247 A and ARI-129, whereas degree of inhibition of the enzyme by L-isoleucine was the same among three strains.
Among auxotrophic mutants derived from ARI-129, adenine and lysine auxotrophs produced more L-isoleucine than the parent did.
In the adenine auxotroph, L-isoleucine production was markedly reduced by the addition of excess adenine.

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Synthesis of nucleosides by the pentosyl transfer reaction in Ps. trifolii (IAM-1555) was studied. The ribosyl transfer reaction between purine or pyrimidine bases and their nucleosides as an acceptor and a donor, respectively, was observed in the presence or absence of inorganic phosphate, and the participations of nucleoside phosphorylase in the former and nucleoside N-ribosyltransferase in the latter were suggested. This transribosylation to the base in the latter was observed to proceed stoichiometrically between pH 6 and 9.5, but the apparent optimal pH in the former was observed at around 10.5. Effects of cultural condition of bacterium, reaction temperature and metallic ions on this reaction and acceptorand donor-specificities were studied in detail.

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A xylan from bamboo culm was isolated by extraction with alkali of chlorite holocellulose and fractional precipitation as a copper complex. The structure was investigated by means of examination of acid components by controlled hydrolysis, methylation analysis, and periodate oxidation. As a result, 4-O-methyl-α-D-glucuronic acid and 2-O-(4-O-methyl-α-D-glucopyranosyluronic acid) D-xylose were isolated and identified as acid components of the bamboo xylan. Hydrolysis of the fully methylated products afforded 2, 3, 5-tri-O-methyl-L-arabinose (1.6 moles), 2, 3, 4-tri-O-methyl-D-xylose (1.2 moles), 2, 3, 4, 6-tetra-O-methyl-D-glucose(0.4 moles), 2, 3-di-O-methyl-D-xylose (35.8 moles) and mono-O-methyl-D-xylose (2.6 moles). In addition to the above methylated sugars, 2, 3, 4-tri-O-methyl-D-glucu-ronic acid and partially methylated aldobiouronic acid were separated by cellulose column chromatography and identified. These results suggest that the bamboo xylan consists mainly of a linear backbone of 1, 4-linked β-D-xylopyranose unit, to which L-arabinofuranose and 4-O-methyl-D-glucuronic acid were attached as a single side chain unit at C₂ or C₃.
Additional evidence for a linear chain structure has been given by periodate oxidation. On oxidation by periodate, the bamboo xylan consumed 1.09 moles of periodate and produced 0.05 mole of formic acid per anhydroxylose unit.

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On the basis of the ratio (cell's respiration rate/maximum oxygen demand of cells, r_ab/K_rM) as a new criterion of oxygen supply, symptoms of oxygen deficiency was described in inosine fermentation. Conversions of the products were observed to occur in relation to the extent of oxygen deficiency. When oxygen demand of the cells was satisfied (r_ab/K_rM=1.0), the cells accumulated exclusively inosine. Under limited oxygen supply at the value of r_ab/K_rM 0.5_??_0.9, on the other hand, inosine formation was inhibited and acetoin was the predominant product. When oxygen supply was limited more strictly at the value of r_ab/K_rM smaller than 0.3, the cells excreted 2, 3-butyleneglycol as the main product.

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Enzymic oxidizing system of 1, 3-butanediol in chicks was studied in comparison with that in rats. 1, 3-Butanediol was oxidized with NAD⁺ as a cofactor in the cytosol fraction of chick liver, kidney, and rat liver. NADP⁺ was about 40% as effective as NAD⁺ in chick liver, kidney, whereas the former was ineffective in rat liver. Inhibitory effect of pyrazole on 1, 3-butanediol dehydrogenase activity was recognized distinctly both in chicks and rats, but the effect was much higher in rat liver than that in chick liver and kidney. Both in chicks and rats, the conversion of 1, 3-butanediol to β-hydroxybutyric acid was detected clearly, and the rate of β-hydroxybutyrate production increased remarkably by employing NAD⁺-regenerating system, i.e., lactic dehydrogenase and pyruvic acid. β-Hydroxybutyric acid was also formed from acetaldol, the most probable intermediate of 1, 3-butanediol, with NAD⁺ both in chicks and rats. From the observations for coenzyme specificity, inhibitory effect of pyrazole, and so on, it is concluded that appreciable difference may be present in 1, 3-butanediol oxidizing system between chicks and rats.

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Bacillus No. C-59-2 isolated from soil produced a xylanase in alkaline media. The characteristic point of this bacteria was especially good growth in alkaline media, and no growth was observed in neutral media such as nutrient broth. The xylanase of this bacteria was purified by CM-cellulose, hydroxyl apatite and Sephadex G-75 columns. The enzyme was most active at pH 5.5_??_9 which was much broader and higher than those of other xylanases. The sedimentation constant was about 3.5S and isoelectric point was pH 6.3. The enzyme was most stable at pH 7 and calcium ion was effective to stabilize the enzyme. The enzyme activity was inhibited by Hg²⁺, Ag²⁺ and Cd²⁺ Maximum hydrolysis rate of xylan by the enzyme was about 40%. The enzyme split xylan and yielded xylobiose and higher oligosaccharides. Therefore, this enzyme is considered to be a type of endo-xylanase.

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A culture medium has been devised for producing colominic acid in improved yields. Major improvements were obtained by using sorbitol as a source of carbon, by adding phosphate in high concentrations, and by supplementing a limited amount of yeast extract. E. coli O 16:KI:HNM produced approximately 3000μg/ml of colominic acid on cultivation at 37°C for 46 hr with a liquid medium consisting of sorbitol (2.0%), (NH₄)₂SO₄ (0.5%), K₂HPO₄ (1.4%), MgSO₄•7H₂O (0.05%), and yeast extract (0.05%).
Isolation and purification by deproteinizationwith ammonium sulfate, precipitation with ethanol, and by column chromatography on anion exchange resins resulted in a pure colominic acid preparation devoid of internal ester linkages.
In producing colominic acid, strains forming S-type colonies were more active than those forming R-type colonies.

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When conidia of Aspergillus sydowi IAM 2544 was incubated with sucrose, polyfructan and oligofructans were synthesized concomitantly in the incubation mixture. The polyfructan isolated from the incubation mixture was shown to have a molecular weight of the order of 20×10⁶ which was comparable to those of microbial levans. But it was comprised of chains of 2→1' linked β-D-fructofuranoside residues as in inulin of higher plants. This polyfructan was considred to be a very unique polysaccharide which differed from any other fructans ever known. Oligofructans were characterized as fructans of 1-kestose series having the general formula of ((1^F-(fructosyl)_n-sucrose)).

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Six strains of bacteria belonging to Vibrio and Pseudomonas were selected as good producers of L-DOPA from L-tyrosine out of various bacteria. The condition for the formation of L-DOPA by Vibrio tyrosinaticus ATCC 19378 was examined and the following results were obtained. (1) Intermittent addition of L-tyrosine in small portions gave higher titer of L-DOPA than single addition of L-tyrosine. (2) Higher amount of L-DOPA was produced in stationary phase of growth than in logarithmic phase. (3) Addition of antioxidant, chelating agent or reductant such as L-ascorbic acid, araboascorbic acid, hydrazine, citric acid and 5-ketofructose increased the amount of L-DOPA formed. (4) L-Tyrosine derivatives such as N-acetyl-L-tyrosine amide, N-acetyl-L-tyrosine, L-tyrosine amide, L-tyrosine methyl ester and L-tyrosine benzyl ester were converted to the corresponding L-DOPA derivatives.
In the selected condition about 4mg/ml of L-DOPA was produced from 4.3mg/ml of L-tyrosine.

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Using 3-(3', 5'-dichlorophenyl)-5, 5-dimethyloxazolidine-2, 4-dione labeled with ¹⁴C or ³H, absorption, excretion, and tissue distribution in male Wistar rats were studied, and metabolites excreted were identified. At the dosage rates of 100, 300, 1000 and 3000mg/kg, the maximum excretion of orally administered radioactivity occurred within 24 hr. Increase in the dosage rate was paralleled by decrease in the proportion of urinary elimination. Essentially all the radioactivity was excreted in 2 weeks. DDOD level was generally low in most tissues. Adipose tissue contained higher radioactivity compared with others. Most of the urinary metabolites identified were characterized by hydroxylation at the 4' position of the benzene ring moiety, and hydrolytic or oxidative modification of the oxazolidine ring portion.

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The structure of a metabolite, C₁₀H₁₀O₅ (I), obtained as a weakly toxic substance from the culture filtrate of Alternaria kikuchiana, was determined as 3, 6, 8-trihydroxy-3-methyl-3, 4-dihydroisocoumarin (Ia). Though three tautomeric forms-lactol form (Ia), keto form (Ib) and enol form (Ic) were possible for (I), it was found that the compound (I) existed as the lactol form (Ia) both in a crystalline state and in acetone, chloroform and methanol solutions. This metabolite gave weak necrotic symptom to pear leaves, but stimulated the root elongation of rice and radish seedlings (ca. 20_??_30%) at 5ppm and also showed synergistic activity with gibberellin A₃ on the stem elongation of rice seedlings (ca. 30%).

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Aroma components were isolated from roasted green tea (Hoji-cha) and identified by IR and GC-MS.
A total of 66 compounds including 21 pyrazines were identified.
On comparison of aroma pattern of Hoji-cha with that of original green tea, it was clear that pyrazines were produced significantly while alcohols were reduced remarkably by roasting.

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It is possible to determine the sequence of a dipeptide containing glutamic acid as a constituent and also to decide whether the glutamyl bond is a or γwhen glutamic acid is the N-terminal component by measuring the NMR spectra of the peptide in acidic, aqueous and basic solutions.

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The mechanism of inactivation of a double-stranded DNA phage, phage JI of Lactobacillus casei, by reducing agents containing thiol group (s) other than glutathione was studied mainly with dithiothreitol (DTT).
Air bubbling, oxidizing agents, and transition metal ions enhanced the rate of phage inactivation by DTT. Partial oxidation of DTT resulted in a more rapid rate of phage inactivation. In contrast, nitrogen bubbling, reducing agents including high concentrations of DTT itself, chelating agents, and radical scavengers prevented phage inactivation. Fully oxidized DTT had no phagocidal effect. These results indicate that the inactivating effect of DTT requires the presence of molecular oxygen and is indirectly caused by free radicals involved in the mechanism of DTT oxidation. The target attacked by DTT in phage particle was not protein but DNA; DTT reacted with DNA to produce single-strand scissions in DNA, which were the cause of inactivation of phage.
This was true also for L-Cysteine, 2-mercaptoethanol, and thioglycollate.
Possible mechanisms by which these thiols fail to inactivate phage at high thiol concentrations are also discussed.

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The activities of phospholipids acyl-hydrolases in an enzyme preparation from a mold, Corticium centrifugum, were examined. Lecithin acyl-hydrolase had an optimal pH at 3.5. The reaction proceeded beyond the range of 50%. Sigmoidal curves observed suggested the presence of lysophospholipase in the preparation. The latter enzyme activity was found to be seven times as strong as the former at the same pH. Fractionation by DEAF-Sephadex chromatography and analysis of the reaction products demonstrated that the main component of lecithin acyl-hydrolase was phospholipase B, which hydrolyzed both of fatty acyl ester groups of lecithin. This activity was found to be present as a separate enzyme from most of lysophospholipase.

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1. The egg white, thick and thin fractions, was solubilized in 1.0% SDS solution by vigorous mixing and subjected to gel filtration on a Sepharose 4B column, eluted with 1.0% SDS. The isolated thick and thin ovomucins were found by analytical disc electrophoresis to be free from contamination with lysozyme.
2. In the velocity sedimentation the two ovomucin fractions behave similarly, both comprising at least two components with sedimentation coefficients 35S and 30S.
3. The chemical compositions of the two ovomucin fractions showed only notable difference in that the carbohydrate content of the thick white ovomucin was somewhat higher than that of the thin white ovomucin. The amino acid profiles of the two fractions were similar.

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