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991.
Yoji Tsukada Hiroshi Taki Tsunetake Sugimori 《Bioscience, biotechnology, and biochemistry》2013,77(3):170-172
Riboflavin producing mutant of Zygosaccharomyces soja* was obtained by a treatment with cycloheximide. This mutant actively utilized various sugars and excreted riboflavin to the culture medium in a concentration of 30 to 40 μg per ml. Aerobic condition was prefered to sustain the growth of mutant and glucose catabolism was altered from alcohol fermentation in case of mother strain to respiration in mutant. This paper presents data obtained from morphological and physiological investigations. 相似文献
992.
Ichiro Tomida Hiroshi Kayahara Ryozo Iriye 《Bioscience, biotechnology, and biochemistry》2013,77(11):2549-2555
The degree of racemization in the several activated ester methods of the peptide synthesis was measured in using the critical racemization test, Pro-Val+Pro, with help of gas chromatography. The results were compared with that in the coupling reaction, Leu-Phe+Val, in which no racemization had been reported in the corresponding reaction conditions by F. Weygand et al., when the activated dipeptide esters had been prepared from Z-Leu+Phe-activated esters. The significantly higher racemization was observed in the methods of N-hydroxypiperidine ester and thiophenyl ester, even when the activated dipeptide esters were prepared from Z-Pro+Val-activated esters. On the other hand, almost no racemization was observed in the N-hydroxysuccinimide ester and p-nitrophenyl ester methods. A great extent of the racemization was detected when the activated dipeptide esters were prepared directly from Z-Pro-Val-OH. 相似文献
993.
Daisuke Yoshida Hiroshi Nishigata Takashi Matsumoto 《Bioscience, biotechnology, and biochemistry》2013,77(8):1769-1770
An extracellular exo-maltohexaohydrolase [EC 3.2.1.98] from a Klebsiella pneumoniae (Aerobacter aerogenes) mutant produced about 40% maltohexaose (G6) from short-chain amylose ( =23). Mostly G6 was produced from maltooligosaccharides larger than G6 by an exo-mechanism action. It also hydrolyzed G6 and shorter maltooligosaccharides to give smaller maltooligosaccharides. Its position specificity of action on G3 through G8 was studied with maltodextrins specifically labeled at the reducing-end glucose unit with 14C. The highest frequency of cleavage was at the second bond from the reducing end in G3 through G6. For G7 and G8, the sixth bond from the nonreducing end of the substrate was cleaved with absolute specificity by the exo-mechanism action.Kinetic parameters of the exo-maltohexaohydrolase on various substrates were also studied. The Michaelis constant (Km) for short-chain amylose was the smallest among the various substrates examined.G6 was also formed from G4 by a transfer action of the enzyme, with an action pattern dependent on the substrate concentration. 相似文献
994.
Yoshinori Takino Hiroshi Imagawa Hiroyuki Yoshida 《Bioscience, biotechnology, and biochemistry》2013,77(10):699-704
Yellow needle crystals, C21H20O13?H2O have been isolated from tea leaves. The crystals yield myricetin (hexaacetate, m.p. 211~212°C), glucose and galactose on hydrolysis. As analytical data indicate the molecular ratio of myricetin to the sugars to be 1:1 and the only bonding position of the sugars to be position 3 of the aglycone, the crystals are concluded to consist of two kinds of glycosides, namely myricetin-3-glucoside and myricetin-3-galactoside. 相似文献
995.
Kiyoshi Miwa Hiroshi Matsui Mahito Terabe Shigeru Nakamori Konosuke Sano Haruo Momose 《Bioscience, biotechnology, and biochemistry》2013,77(11):2901-2903
Seven filamentous (fil) mutants were isolated from B. subtilis, and the mutations were mapped by means of lysed-protoplast transformation. Five of the mutations were linked to aroD and the others to pyrD. rgn mutations, which lead to a decrease in autolysin(s) and the formation of filaments, were also linked to aroD, and the mapping order was rgn-dnaE-aroD. On comparison with other reported filamentous mutations (lyt-1, lyt-2 and lyt-152), fil-1, fil-3 to -6, rgn and the above lyt mutations were determined to be in the same locus. All of the seven fil strains lacked flagella and showed decreased aμtolysin activity. Among them, only mutants having arod- linked mutations showed low competency. Protease assay results indicated that rgn mutants produce a several times higher amount of the enzyme than the parent strain, and the initiation time for the production in rgn mutants was two hours earlier than in the parent strain. 相似文献
996.
Hiroshi Sugimoto 《Bioscience, biotechnology, and biochemistry》2013,77(10):1111-1123
This paper deals with yeast cell-wall lytic enzymes formed by Streptomyces with regard to the connection with the cell-wall structure.In the first place, 29 organisms of β-glucanase-producing Streptomycetes were selected among 777 strains belonging to genus Streptomyces by means of a cylinder-plate method employing the yeast glucan as a substrate. As for these organisms, the depolymerizing activity against the yeast glucan was considered to be mainly due to β-1,3-glucanase activity. Against the heat-treated cell of bakers’ yeast, the crude enzymes merely showed poor lytic activities, however, in the combined employment with some protease preparations, especially with an alkaline protease from St. satsumaensis nov. sp., a remarkable increase of the lytic activities was demonstrated. On the other hand, the intact cell wall of bakers’ yeast, or both the heat-treated and the intact cells of Sacch. cerevisiae 18.29 strain were dissolved very easily by a sole action of β-glucanase or of protease, respectively. In consequence, it seemed that the lysis occurred with different mechanisms in response to differences of substrates. On this subject, the results of investigations and discussions were described in special measure. In addition, the possibility, that some other enzymes than β-glucanase or protease might concern to the lysis of the cell wall, was also investigated and discussed. 相似文献
997.
998.
Hiroshi Abe Masaaki Uchiyama Rokuro Sato 《Bioscience, biotechnology, and biochemistry》2013,77(12):2259-2260
Endosperm cell walls were isolated from rice grains and their chemical composition was analyzed. The cell walls were composed of cellulose microfibrils and matrix phase which consisted of hemicellulose and pectic substances. Hemicellulose mainly comprised arabinoxylan, accompanied by a small amount of glucose-containing polysaccharide. Pectic substances contained polygalacturonides, some of which had side chains containing neutral sugars such as galactose and arabinose. Amino acid analysis of these fractions suggested that hydroxyproline-containing glycoproteins were contained in these cell walls and firmly bound to cellulose microfibrils. 相似文献
999.
Hiroshi Ohrui Hiroyoshi Kuzuhara Sakae Emoto 《Bioscience, biotechnology, and biochemistry》2013,77(3):375-380
2,5-Anhydro-3-azido-3-deoxy-D-xylose dimethyl acetal (XI), the key intermediate for the stereospecific synthesis of d-oxybiotin, was prepared by methanolysis of 3-azido-3-deoxy-1,2-O-isopropylidene-5-O-p-tolylsulfonyl-α-d-xylofuranose (VIIIa) or of 3-azido-3-deoxy-l,2-O-cyclohexylidene-5-0-p-tolylsulfonyl-α-d-xylofuranose (VIIIb). 相似文献
1000.
The Cotton effect below 200 nm was first studied in aromatic glycopyranosides with our new technique of optical rotatory dispersion (ORD). The phenyl and p-nitrophenyl α- and β-d-glycopyranosides showed a strong Cotton effect at around 180 nm which practically governed the optical rotations in the visible wavelength region. The rotational strength and sign of this Cotton effect were shown to reflect the anomeric configurations and conformations, which led to an extension of the ring oxygen helicity rule for alkyl and alkyl 1-thioglycosides to aromatic glycopyranosides. 相似文献