The aroma concentrates of roasted whole seeds (a) and defatted seeds (b) of Citrullus colocynthis var. colocynthoides, as well as that of the lipid fraction (e) were subjected to a through investigation. Samples of (a) and (b) were separated into neutral-acidic and basic fractions. The former was further fractionated into carbonyl and non-carbonyl compounds.
Characterization of the individual components for each fraction of the corresponding sample was achieved by a chromatography-mass spectrometry coupling technique under favourable conditions. A comparison of the individual components within the samples revealed major differences. The role of lipids, carbohydrates and amino-acids in developing aroma during the roasting process is discussed.

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The photoillumination of assimilatory nitrate reductase of Hansenula anomala in the presence of Rose Bengal caused a selective inactivation of NAD(P)H-linked activities. The potent protective effect of NAD(P)H suggests that the residue(s) modified by the treatment is involved in electron transport from NAD(P)H. From the observation that p-chloromercuribenzoate-treated enzyme was potomodified similarly to the native enzyme, the photomodified residue(s) is deduced not to be cysteine. The parallel decrease of NAD(P)H-nitrate reductase activity and the histidine contents suggests that histidine residue(s) is involved in this inactivation.

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The substrate specificity and the mode of action of the protease from Streptomyces cellulosae were investigated, using many kinds of peptides and proteins as substrates. The protease hydrolyzed peptides consisting of hydrophobic amino acids such as L-Phe-L-Leu-NH₂, L-Pro-L-Phe-NH₂, L-Leu-L-Met, L-Leu-L-Leu, Gly-L-Ile, L-Phe-L-Phe, L-Pro-L-Leu-Gly-NH₂, etc. The protease hydrolyzed zein best among the proteins tested, but weakly hydrolyzed gelatin, myoglobin, bovine serum albumin, γ-globulin, and collagen. The protease mainly hydrolyzed Ser¹²-Leu¹³, Leu¹³-Tyr¹⁴, and Tyr¹⁴-Gln¹⁵ bonds in the oxidized A-chain of insulin and at least the Leu¹⁵-Tyr¹⁶ bond in the oxidized B-chain of insulin.

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A simple and reliable method for the determination of NO₃-¹⁵N or NO₂-¹⁵N and application of the method to plant material are described. 4-¹⁵NO₂-2-sec-Butylphenol, which was produced by reaction of ¹⁵NO₃^- and 2-sec-butylphenol in aqueous (5 + 7) sulfuric acid at room temperature for 15min, was subsequently trimethylsilylated to obtain its trimethylsilyl ester. Whereas [¹⁵N]-tetrazolophthalazine was produced by reaction of ¹⁵NO₂^- and hydralazine in acidic medium at 70°C for lOmin. The determination of NO₃-¹⁵N and NO₂-¹⁵N was achieved after formation of these compounds by gas chromatography-mass spectrometry with selected ion monitoring. The method is specific for NO₃-¹⁵N or NO₂-¹⁵N and enables the determination of these anions in plants without any clean-up stage. The detection limits for NO₃-¹⁵N and NO₂-¹⁵N in plant material (komatsuna) were 0.75 × 10^-6g and 0.13 × 10^-6g per sample, respectively. The proposed method was applied to determine NO₃-¹⁵N and NO₂-¹⁵N in plants precisely.

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Our previous study revealed the presence of some potent antioxidative components other than γ-tocopherol and sesamol in sesame seed and oil. In the present study, the effective components were extracted from mashed sesame seed with acetone, followed by removal of triglycerides by freezing. The acetone extract showed strong antioxidative activity with the thiocyanate method and gave 4 active antioxidative substances after a series of chromatographic separations. The molecular formulae were determined to be C₂₀H₂₀O₆ (PI), C₂₀H₂₀O₇ (P2), C₂₀H₁₈O₇ (P3) and C₁₀H₁₀O₄ (P4). Compounds PI and P4 were respectively identified as a bisepoxylignan analogue and trans-ferulic acid. Though preliminary structural data for P2 and P3 indicate them to be a sesamolin analogue and a sesamin analogue, respectively, work is currently underway to confirm this. The antioxidative activities were in the order of P3 > P2 > P1 > P4. The same components were also obtained from the 80% ethanol extractable polar fraction of the sesame oil cake treated with β-glucosidase, which suggested the presence of the active substances also as their glycosides in sesame seed.

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A few developmental studies like hydrolysis, phytotoxicity and photolysis on O, O-bis(2, 4, 5-trichlorophenyl)methylphosphonate, a potential fungicide, were carried out. The compound had a half life of 15 and 3hr respectively at pH 8 and 10, and did not show any phytotoxicity on the germination of paddy, brinjal and cauliflower seeds as well as on young paddy seedlings. A possible photochemical transformation based on the isolation of methylphosphonic acid is also proposed.

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Natto, a traditional Japanese food product, was prepared from cooked soybeans by fermentation and its odor concentrate was obtained with a simultaneous distillation and extraction system. It was compared to those obtained from soybeans cooked for 0-3, 3-5.5 and 5.5-8hr, respectively, by gas chromatography and gas chromatography-mass spectrometry. In the odor concentrates of the cooked soybeans, hexanal, (E)-2-hexenal and hexanol contributing to the green and grassy odor of soybeans disappeared or decreased while the cooking was in progress. 2-Pentylfuran and l-octen-3-ol contributing to the beany odor remained even if the soybeans were cooked for 8 hr and were fermented into Natto. In the odor concentrate of Natto, pyrazines and sulfur containing compounds were important contributors to the characteristic odor of Natto. As the beany odor was not detected for Natto, it was concluded that the pyrazines and sulfur containing compounds cause the characteristic odor of Natto and mask the beany odor.

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Tea leaf amine oxidase was purified by salting out and various column chromatographies. The molecular weight was estimated to be 162, 000 daltons by gel filtration on a Sephadex G-200 column. This enzyme was determinated to be a dimer of which the molecular weight was found to be 81, 000 daltons by SDS gel electrophoresis. The optimum pH for ethylamine oxidation by this enzyme was 7.0. The enzyme was stable up to 60°C From the results of a inhibition study with chelating agents, the enzyme was found to contain copper in the cupric state. Carbonyl reagents such as semicarbazide, hydroxylamine and hydrazine strongly inhibited the activity. The enzyme oxidized alkylamines, ethanolamine and benzylamine rapidly, and also oxidized tyramine, histamine and other diamines slowly. The Km value for ethylamine was 8.8 × 10^-5M. Polyamines, secondary amines and tertiary amines were not oxidized.

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The biosynthetic origin of the ansa-structure of ansamitocin P-3 was investigated by feeding ¹⁴C- and ¹³C-labeled compounds. The results suggested that the ansa-structure was constructed from a long aliphatic chain composed of three C₂-units directly derived from acetate, one C₂-unit derived from metabolites of glucose and three C₃-units derived from propionate, and an aminobenzenoid nucleus derived from metabolites of glucose. Three C₁-substituents, two O-methyl and one N-methyl group in the sructure were derived from the C-2 of glycine and the S-methyl of methionine. A cyclic carbinolamide was derived from the carbamoyl of citrulline.

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Continuous synthesis of oleic acid glycerides by seven Upases available commercially were compared at 40°C using the microporous hydrophobic membrane bioreactor we developed recently. The lipases produced by Rhizopus japonicus, Candida cylindracea, and Phycomyces nitens were quickly inactivated in 97% glycerol solution and yielded very low glyceride conversions. The other four lipases yielded glyceride synthesis activities in the order: Rhizopus delemer's<Pseudomonas fluorescens's< Mucor miehei's<Chromobacterium viscosum's. For these four lipases, there was a hyperbola-like relationship between the conversion and the amount of lipase adsorbed at the membrane during the reaction. The adsorbed lipase desorbed relatively easily when glycerol-water-lipase solution was replaced by fresh 97% glycerol solution having no lipases. Mucor miehei's lipase was adsorbed more strongly than Chromobacterium viscosum's. The product produced by Mucor miehei's lipase was composed mostly of mono- and di-glycerides while the one produced by Pseudomonas fluorescens's was composed of mono-, di-, and tri-glycerides with an approximate molar ratio of 3:4:1. The contents of 2-monoglyceride and 1, 2-diglyceride isomers in the product having about 80% conversion produced by Mucor miehei's lipase were quite small. The approximate half-life of Mucor miehei's lipase was estimated as 54 days from a continuous reaction experiment carried out for 27 days.

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The transfer action of Bacillus subtilis levansucrase was further studied and the following results were obtained: the levan synthesized on raffinose by the enzyme contained one mole of galactosylglucose per mole as one of the two terminal glycosyl moieties. The enzyme synthesized levanbiose in a mixture of fructose and ¹⁴C-fructose-containing sucrose and the ether linkage formed was between the C2 of labelled fructose and the C6 of non-labelled fructose. The transfer of fructosyl residues by the enzyme was suppressed as the ionic strength of the reaction mixture increased. This suppression effect of ionic strength was severe in the synthesis of high molecular weight levan. The hydrolysis of levan by the levansucrase was also suppressed by the increase of ionic strength, but this effect occurred with almost the same degree in the hydrolysis of both low and high molecular weight levans. On the basis of these results, the extending direction of the levan molecule and the exclusive synthesis of low molecular weight levan in the presence of high ionic strength are discussed.

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In order to investigate the mechanism by which exogenous plasmids are stabilized and maintained in Bacillus subtilis, a complex plasmid, pTUEB24 (14kb), composed of pBR322, pUB110 and the aroI⁺ tmrB genes from B. subtilis chromosomal DNA, was constructed. This plasmid was introduced into B. subtilis cells by the protoplast and competent cell transformation methods. Plasmids were re-extracted from Km^r transformants. Their molecular size was reduced to 6.3kb on average by protoplast transformation and to 5.7kb by competent cell transformation. These reductions in molecular size were caused by deletions in the pBR322 and aroI⁺ tmrB DNA regions of pTUEB24.
To determine the fate of pTUEB24 during the transformation procedure, DNAs were extracted from the medium, cell membrane and cytoplasm fractions. pTUEB24 was degraded unexpectedly on contact of the DNA with protoplasts and then degraded in the cytoplasm. Nuclease-deficient mutants of B. subtilis are desirable for the effective use of this bacteria in gene engineering.

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We investigated the allosteric and kinetic properties of the heat-stable L-lactate dehydrogenase (EC 1.1.1.27) from Thermus caldophilus GK24. In the absence of an effector, the pyruvate and L-lactate saturation curves for the enzyme were sigmoid. In the presence of 0.2 mM fructose 1, 6-bisphosphate, the most potent effector, the substrate saturation curves ceased to show the positive cooperativities. The maximum velocity of pyruvate reduction increased 7-fold on the addition of fructose 1, 6-bisphosphate. This fructose 1, 6-bisphosphate-dependent enzyme activity was strongly inhibited by high concentrations of the substrate (pyruvate). In contrast, the NADH and NAD⁺ saturation curves for the enzyme were hyperbolic independent of fructose 1, 6-bisphosphate. Glucose 1, 6-bisphosphate, fructose 2, 6-bisphosphate and 5-phosphoribosyl 1-pyrophosphate also activated the enzyme to some extent. Inorganic phosphate slightly activated the enzyme, while it was rather inhibitory for the fructose 1, 6-bisphosphate-dependent enzyme reaction. Oxamate, an analogue of pyruvate, activated the enzyme and caused the positive cooperativity for pyruvate to disappear. The intracellular concentrations of fructose 1, 6-bisphosphate and pyruvate and the kinetic properties of L-lactate dehydrogenase of T. caldophilus Gk24 indicate that the enzyme exhibits the pyruvate reduction activity in concert with glycolysis under allosteric regulation by fructose 1, 6-bisphosphate.

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A subtilisin inhibitor was isolated from adzuki beans (Phaseolus angularly) by chromatography on CM-cellulose, Sephadex G-75, DEAE-cellulose, and SP-Sephadex C-25. The final preparation was confirmed to be homogeneous on polyacrylamide gel electrophoreses, and its pi value was 3.7. The preparation was a powerful inhibitor of microbial serine-proteinases but its activity was destroyed by trypsin and chymotrypsin. Dissociation constant of the complex of the inhibitor with subtilisin was 0.16nM. The inhibitor was heat-stable over the pH range examined in spite of a lack of intramolecular disulfide bonds: little or no subtilisin-inhibitory activity was lost at 80°C for 10min, though heating to 100°C at.pH 12 caused a decrease of about 50% in the activity. The inhibitor molecule consisted of 97 amino acid residues, containing relatively large amounts of glutamic acid and valine residues and no half-cystine residues, unlike adzuki-bean proteinase inhibitors I and II. The molecular weight of the inhibitor was determined to be 12, 300 by gelfiltration and calculated to be approximately 11, 000 on the basis of the amino acid composition.

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Starch granules were isolated from polished grains of rice plants (Oryza sativa L.), waxy and nonwaxy near-isogenic lines of a Japonica rice cultivar, Taichung 65, grown under controlled temperature conditions. Amylose contents and distributions of α-1, 4 chains of amylopectin, and further details of the fine structure of waxy amylopectin were determined by enzymatic and chromatographic methods. The higher environmental temperature decreased amylose contents in endosperm starches of nonwaxy rice plants. Moreover, the higher environmental temperature increased the amount of long B chains of amylopectin and decreased mainly that of short B chains and slightly that of A chains as compared with the lower environmental temperature.

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We characterized the macromolecular synthesis of 3 "short-survival" (3YltsA106, 3YltsB107, and 3YltsC113) and 4 "long-survival" (3YltsD123, 3YltsF121, 3YltsG125, and 3YltsH203) temperature-sensitive mutants of rat 3Y1 diploid fibroblasts under various conditions. Inhibition of RNA synthesis was the earliest event detectable in 3YltsB107 and 3YltsC113, and DNA synthesis was inhibited in all the long-survival mutants. In the long-survival mutants, levels of RNA synthesis of temperature-arrested and density-arrested states differed. Results of cycloheximide treatment of temperature-arrested cells after shifting down to 33.8°C suggest that de novo protein synthesis is necessary for DNA synthesis to resume and also that inhibition of protein synthesis delays initiation of DNA synthesis in 3YltsD123, 3YltsF121, and 3Y1tsG125.

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Mass spectrometry using selected ion monitoring, high-performance liquid chromatography and an Amaranthus betacyanin bioassay enabled six endogenous cytokinins to be identified from potato (Solanum tuberosum L. cv. Danshaku) tubers, and their levels to be determined. 9-β-D-Glucopyranosyl 6-(3-niethyl-2-butenylamino)purine, a new glucopyranosyl derivative of i⁶ Ade, was found from the tubers.

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Winged bean basic lectin was purified by affinity chromatography on p-aminophenyl-β-Dgalactopyranoside bound Sepharose 4B. The purified lectin was homogeneous on polyacrylamide gel electrophoresis, isoelectric focusing, and gel filtration. The molecular weight of the lectin was 53, 000±1, 800 by gel filtration, SDS-polyacrylamide gel electrophoresis gave a single component of molecular weight of 27, 000, suggesting that the lectin was a dimer. The isoelectric point was pH 8.62±0.17. The basic lectin was rich in aspartic acid and threonine, and poor in sulfur-containing amino acids. The basic lectin agglutinated both trypsinized and untreated human erythrocytes; it bound highest with type A, somewhat lower with types B and AB, and negligibly with type O erythrocytes. Among the tested sugars, D-galactose and N-acetyl-D-galactosamine were active in inhibiting the hemagglutination. In contrast, the determinant sugars in blood group O, such as L-fucose and N, N'-diacetylchitobiose, were entirely inactive, confirming the blood group-specificity of the basic lectin. Modification of the lectin with N-bromosuccinimide led to a significant decrease in its hemagglutinating activity, suggesting contribution of the tryptophan residues to the activity.

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Humulone, lupulone and related compounds were found to have antifungal activities. The activities of these compounds were tested to determine their structure-activity relationships.
As a result, it was found that the six-membered compounds had antifungal activities against Trichophyton spp., whereas, the flve-membered compounds were inactive. Among the compounds tested, 3-isopentenylphlorisovalerophenone 12 showed the highest activity, being almost the same as griseofulvin against Trichophyton spp. 12 also had potent activity against Candida, Fusarium, Mucor and Staphylococcus spp. It is suggested that the activity of 12 was significantly affected by the structue of its acyl group.

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Phosphate buffer suspensions of resting Escherichia coli B cells at pH 7.0 were anaerobically exposed to an alternating current (AC) of 50 Hz at a current density of 600 mA/cm² and 34±3°C. The AC-exposed cells required a higher concentration of a cationic flocculant, poly(methacryloxyethyl-trimethyl-ammonium chloride), to form cell floes than unexposed cells. The electrophoretic mobility of the cells increased after AC-exposure. Oxygen uptake by the exposed cells in a neutral reaction mixture decreased with increasing exposure time. The cells were less easily stained with crystal violet after AC-exposure. These observations show that AC-exposure causes an increase in the amount of the negative surface charge of E. coli cells and changes in some physiological properties.

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All geometrical isomers of 5, 7-, 6, 8-, 7, 9-, 8, 10- and 9, 11-dodecadien-1-ols, and their acetates and aldehyde derivatives were analyzed by electron impact mass spectrometry. The abundance of molecular ion (M⁺) was observed in every spectrum, and the relative intensity of M⁺ tended to be strong if the compound possessed an (E)-double bond(s). In addition to M⁺, [M -H²O] ⁺ (alcohols) and [M -CH₃CO₂H]⁺ (acetates), every dienic compound showed typical series of C_nH_2n-2⁺∼C_nH^2n-5+ with abundance maxima around C₄, C₅, C₆ or C₇. Each double bond positional isomer characteristically yielded different ion peaks in the series, which were useful for its distinction from other isomers. These results indicate that the chemical structure of a natural pheromone of Lepidoptera is easily deduced successfully by GC-MS analysis if it is a conjugated dienic pheromone.

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The immunogenic properties of glycosylated ovalbumin were investigated by measuring specific IgE and IgG antibody responses in mice. Ovalbumin was glycosylated with glucose through Maillard reaction. The glycosylated protein reacted well with the antibody to native ovalbumin. The glycosylated and native ovalbumins were injected into mice, and serum IgE and IgG responses were determined by the passive cutaneous anaphylaxis (PCA) test and a solid phase enzyme immunoassay (ELISA). The glycosylated ovalbumin induced rather lower responses of both IgE and IgG antibodies than native ovalbumin did, and the antibody directed against glycosylated ovalbumin reacted with native protein. These results suggested that immunogenic properties of proteins could be altered by the glycosylation through Maillard reaction.

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In order to obtain information for preparation of good quality malt, changes in endogenous abscisic acid (ABA) in barley during malting were studied. When barley was steeped aerobically, the ABA level in the barley kernel greatly decreased. The activity level of the ABA metabolic system linked to the start of germination was estimated. The level of ABA increased during the germination stage with the development of each embryonic organ. On the basis of these results, the effects on malt quality of ABA plus gibberellic acid (GA₃) added to barley during malting were examined. With appropriate combinations of ABA and GA₃, malt with good quality was obtained in high yield.

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Susceptibility of animal α-amylases to a proteinaceous α-amylase inhibitor, Haim, vary with species of the animal and among organs of the same animal. Haim strongly inhibits, α-amylases from vertebrates, and weakly inhibits those from Mollusca, Annelida, and Arthropoda. The results suggest that susceptibility of animal α-amylases to Haim may correlate well with the classification of the animal. Haim had greater specificity for human salivary amylase than for human pancreatic amylase, and greater specificity for rat pancreatic amylase than for rat salivary amylase.
Maximum inhibition of hog pancreatic amylase by Haim occurred after preincubation of the enzyme and its inhibitor at 37°C for 3 min. The time required to reach maximum inhibition was shorter for Haim than for inhibitors from kidney bean and wheat.
Complex formation between Haim and hog pancreatic α-amylase was seen by UV difference spectroscopy. That the molar complex was 1:1 was also shown by the same method and by an inhibition curve.

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The metabolism in rats of dihydrocapsaicin, a pungent principle of hot pepper, was investigated in vivo and in vitro by thin-layer chromatography, high-performance liquid chromatography and combined gas chromatography-mass spectrometry. Within 48 hr of oral administration of dihydrocapsaicin (20 mg/kg body weight) to male adult rats, unchanged dihydrocapsaicin and eight of its metabolites were identified in urine; i.e., dihydrocapsaicin (8.7% of total dose), vanillylamine (4.7%), vanillin (4.6%), vanillyl alcohol (37.6%) and vanillic acid (19.2%) as free forms and/or their glucuronides. The proportions of free and glucuronide metabolites in urine were 14.5% and 60.5% of the total dose. Part of the unchanged dihydrocapsaicin (10% of total dose) was excreted into the feces within 48 hr. Cell-free extracts of rat liver catalyzed the hydrolysis of dihydrocapsaicin to vanillylamine and 8-methyl nonanoic acid. The former compound was further transformed to vanillin in situ. Dihydrocapsaicin-hydrolyzing enzyme activity was found in various organs of rat. The activity was located mainly in the liver. On the basis of the present data, the metabolic pathway of dihydrocapsaicin in rats was proposed.

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A new polygalacturonase was found in a culture filtrate of Aureobasidium pullulans. The enzyme was purified and obtained in crystalline form with 10% recovery. The crystalline enzyme was a homogeneous protein by analyses by sedimentation and electrophoresis. The enzyme was most active around pH 4.5, and stable in the pH range of 4 to 6. Its molecular weight was 42, 000 and its isoelectric point was pH 6.0. The enzyme was an endo-polygalacturonase, catalyzing the cleavage of glycosidic bonds of polygalacturonic acid at random.
The enzyme had less protopectinase activity than those of the endo-polygalacturonases that were isolated as protopectin-solubilizing enzymes from Trichosporon penicillatum, Kluyveromyces fragilis, and Galactomyces reessii. Some characteristics were compared with the endo-polygalacturonases, which have potent protopectinase activity.

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The mechanism of the DNA breaking activity of 1-amino-l-deoxy-D-fructose (o-isoglucosamine) in double-stranded replicative form I DNA (RFI DNA) of bacteriophage φX174 was investigated by agarose gel electrophoresis under various conditions. Cu²⁺ was indispensable for DNA strand scission. Induction of scission by D-isoglucosamine was proportional to incubation time and concentration, and was inhibited by the addition of chelating agents (EDTA, DETAPAC), superoxide dismutase (SOD), catalase, and some other free radical scavengers. These results suggested that DNA strad scission by D-isoglucosamine was caused by oxygen radicals generated during the autoxidation of D-isoglucosamine in the presence of Cu²⁺.

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Equimolar aqueous solutions of D-glucose and n-butylamine were heated at 95°C for various times at pH 4, 6.5 and 11.48. The resulting brown solutions were extracted with ether. The volatile components in the ether extracts were analyzed by gas chromatography and gas chromatographymass spectrometry, with a fused silica capillary column. The major components formed were identified as three alcohols, four N-butylpyrroles, N-butylacetamide, N-butylformamide, N-butylsuccinimide, one pyranone and 5-(hydroxymethyl)-2-furfural. In addition, eleven minor components were also identified. The relative amount of each component changed markedly with pH. At pH 4.0, higher-boiling heterocyclic compounds without C-C fission of glucose were largely formed, and at pH 11.48, lower-boiling fission compounds were mainly formed. Both were observed in the reaction at pH 6.5.

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Synthesis of linear D-manno-oligosaccharides, O-α-D-Man-{(1→3)-O-α-D-Man}_n-(1→3)-O-α-D-Man (n=0∼4), which correspond to part of the structure of the cell-wall polysaccharide of Tremella fuciformis and Dictyophora indusiata FISCH, is described.

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A new series of 1-substituted-5-[(E)-2, 6-dimethyl-1, 5-heptadienyl]imidazoles were prepared and bioassayed for anti-juvenile hormone activity on the silkworm, Bombyx mori. The compounds induced unequivocal precocious metamorphosis in the 3rd and 4th instar larvae by topical application. Of the compounds tested, l-benzyl-5-[(E)-2, 6-dimethyl-1, 5-heptadienyl] imidazole (KK-42) proved to be the most active compound eliciting 100% of precocious pupation at 2 μg/larva on the 4th instar larvae. The E isomer showed considerably higher activity than the corresponding Z isomer. The anti-juvenile hormone effect of KK-42 was counteracted by simultaneous application of JH I or methoprene.

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A simple synthesis of the proposed structure of sclerosporin was accomplished from a symmetrical diketone 10. The synthetic 1 did not show sporogenic activity, although the structure of 1 was rigorously assigned by ¹-NMR at 500 MHz.

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Optically active guaiane dienes, 3 and 4, related to Sclerosporene 2 were synthesized from (-)-carvone and (-)-α-santonin. The mass spectra of 3 and 4 were not identical with that of natural Sclerosporene.

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Multiple forms of dextransucrase were demonstrated by using six subclass strains of Leuconostoc mesenteroides, NRRL B-512F, B-1298, B-1307, B-1355, B-1375, and B-1416. Gel filtration of the dextrans produced at the early stages of culture showed a bimodal distribution of the molecular weight. The total enzyme activity produced amounted to 8.3-32.2 units per 100ml culture among the strains. Partially purified enzyme preparations from six strains gave an intrinsic multiple pattern being resolved into more than two activities on polyacrylamide gel electrophoresis. Judging from the susceptibility to the two different dextranases, types and contents of the secondary linkages in the dextrans synthesized by these enzymes might correspond to the respective native dextrans. In contrast to a linear progress curve for dextran synthesis with the enzymes from B-512F and B-1375 strains, those from B-1298 and B-1416 gave a characteristic sigmoidal curve for the polymerizing (transferase) reaction.

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V79-R Cells grown in lipid-free medium contained octadecenoic acids as the major fatty acids esterified to lipids. Octadecenoic acids were composed of two positional isomers, oleic and cis-vaccenic acids. The distribution of oleic and cis-vaccenic acids was altered by the addition of various fatty acids to the medium. There was no difference in the distribution of oleic and cis-vaccenic acids in phospholipids between mitochondria and microsomes. Cardiolipin contained higher amounts of palmitoleic and cis-vaccenic acids than did other lipids.

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Glucose oxidase was immobilized on the surface of a p-benzoquinone-carbon paste electrode by coating the enzyme-loaded surface with a nitrocellulose film. The electrode was able to oxidize glucose electrocatalytically. It showed high current response to glucose, and was stable for more than a week. The electrode can be used as a glucose sensor that is relatively insensitive to variations of oxygen tension in sample solutions.

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Bacillus subtilis B7, a tmrA mutant, shows both tunicamycin resistance and α-amylase hyperproductivity. The tmrA characters can be transferred simultaneously to recipient cells by DNA-mediated transformation. We found a typical gene amplification phenomenon in the tmrA transformants and B7 strain. The amplified unit, 16.3kb in size, covers α-amylase structural gene amyE to another tunicamycin resistance gene tmrB, which is located 9kb downstream of the amyE gene. About 10 repeating units are supposed to be tandemly repeated in the transformants. Amplification of the wild amyE and tmrB genes could be the cause of the α-amylase hyperproductivity and tunicamycin resistance of the tmrA transformants and B7 strain.

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