Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 67 , Issue 2
Showing 1-43 articles out of 43 articles from the selected issue
Review
  • Hiroshi HABE, Toshio OMORI
    2003 Volume 67 Issue 2 Pages 225-243
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Polycyclic aromatic hydrocarbons (PAHs), which consist of two or more fused aromatic rings, are widespread in the environment and persist over long periods of time. The decontamination of a PAH-polluted environment is of importance because some PAHs are toxic, mutagenic, and carcinogenic and therefore are health hazards. As part of the efforts to establish remediation processes, the use of aerobic bacteria has been extensively studied, and both enzymologic and genetic studies are underway for the purpose of effective biodegradation. In the last two decades, one highly conserved group of PAH-catabolic genes from Pseudomonas species, called the nah-like genes, has been well investigated, and much has been found, including the structure-function relationships and the evolutionary trails of the catabolic enzymes. However, recently, PAH-catabolic genes, which are evolutionarily different from the nah-like genes, have been characterized from both Gram-negative bacteria other than Pseudomonas species and Gram-positive bacteria, and the information about these genes is expanding. This review is an outline of genetic knowledge about bacterial PAH catabolism.
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Organic Chemistry Regular Papers
Organic Chemistry Notes
  • Kensaku TAKARA, Daigo MATSUI, Koji WADA, Toshio ICHIBA, Isao CHINEN, Y ...
    2003 Volume 67 Issue 2 Pages 376-379
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Five new phenolic compounds, 4-(β-D-glucopyranosyloxy)-3,5-dimethoxyphenyl-propanone (8), 3-[5-[(threo) 2,3-dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxybenzofurany]]-propanoic acid (12), 2-[4-(3-hydroxy-1-propenyl)-2,6-dimethoxyphenoxy]-3-hydroxy-3-(4-hydroxy-3,5-dimethoxyphenyl)propyl-β-D-glucopyranoside (13), 4-[(erythro) 2,3-dihydro-3(hydroxymethyl)-5-(3-hydropropyl)-7-methoxy-2-benzofuranyl]-2,6-dimethoxyphenyl-β-D-glucopyranoside (14), 9-O-β-D-xylopyranoside of icariol A2 (15), and known phenolic compounds were isolated from Kokuto, non-centrifuged cane sugar (Saccharum officinarum L.). Their structures were determined by a spectral investigation.
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  • Takehiko YOKOYAMA, Nobuhiro KAN-NO, Takehiko OGATA, Yuichi KOTAKI, Min ...
    2003 Volume 67 Issue 2 Pages 388-392
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Several species of microalgae (phytoplankton), 4 species of freshwater algae and 4 species of marine diatoms, were cultured germ-free in the laboratory. The presence of free D-amino acids was verified in these species by a reversed-phase HPLC analysis. D-Aspartate was detected in all the microalgae examined, but D-alanine was only present in the marine diatoms. The D-amino acid content in Asterionella sp. of the marine diatoms increased from the exponential phase to the stationary phase and then decreased to the phase of decline.
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  • Fumio HASHIMOTO, Masateru ONO, Chikako MASUOKA, Yasuyuki ITO, Yusuke S ...
    2003 Volume 67 Issue 2 Pages 396-401
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Forty-three polyphenols from tea leaves were evaluated for their anti-oxidative effect against lipid peroxidation by the ferric thiocyanate method in vitro. Among these, 1,4,6-tri-O-galloyl-β-D-glucose (hydrolyzable tannin) showed the highest anti-oxidative activity against lipid peroxidation, even stronger than that of 3-tert.-butyl-4-hydroxyanisole (BHA). The assay demonstrates that tea polyphenols, except for desgalloylated dimeric proanthocyanidins that possess a catechin structure in the upper unit and desgalloylated flavan-3-ols, and excepting theaflavin 3,3′-di-O-gallate, had more anti-oxidative activity than that of α-tocopherol. The chemical structure-activity relationship shows that the anti-oxidative action advanced with the condensation of two molecules of flavan-3-ols as well as with 3-O-acylation in the flavan skeleton such as that by galloyl, (3′-O-methyl)-galloyl, and p-coumaroyl groups.
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  • Abdul MUN'IM, Osamu NEGISHI, Tetsuo OZAWA
    2003 Volume 67 Issue 2 Pages 410-414
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Seven antioxidative compounds were isolated from the EtOAc extract of the aerial part of C. sessiliflora (Japanese name, tanukimame) by activity-guided fractionation with 2,2-diphenyl-1-picrylhydrazyl (DPPH). Among the isolated compounds, hydroxyeucomic acid showed the strongest free radical-scavenging activity, which was almost identical to that of epigallocatechin gallate, against DPPH. Orientin and isoorientin showed strong anti-peroxidative activities toward linoleic acid and protective effects against the bactericidal action of the tert-butyl peroxyl radical. Their activities were nearly equal to that of epigallocatechin gallate.
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  • Emiko KADOWAKI, Yasuhiro YOSHIDA, Teruhiko NITODA, Naomichi BABA, Shuh ...
    2003 Volume 67 Issue 2 Pages 415-419
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Guided by a feeding stimulant activity test on the olive weevil (Dyscerus perforatus), two compounds that showed potent feeding stimulant activity were isolated from the olive tree (Olea europaea). Based on their spectral data and a literature survey, they were identified as (−)-olivil (1) and (+)-1-acetoxypinoresinol (2). The activities of these minor lignans were significantly higher for the female than for the male weevil.
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  • Atsumi SHIMADA, Chisako SHIOKAWA, Miyako KUSANO, Shozo FUJIOKA, Yasuo ...
    2003 Volume 67 Issue 2 Pages 442-444
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      A new plant growth regulator, hydroxysulochrin (1), together with sulochrin (2) was isolated from the culture filtrate of Aureobasidium sp. grown on a malt extract medium. The structures of 1 and 2 were established by spectroscopic methods. 1 and 2 inhibited tea pollen tube growth by 41% and 36% of the control value at a concentration of 100 mg/l, respectively. However, 1 and 2 showed no inhibitory effect on the growth of lettuce seedlings from 0.1 mg/l to 100 mg/l.
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Biochemistry & Molecular Biology Regular Papers
  • Kazue MACHIDA, Ryouji ISHIBASHI, Tomoko HARA, Akira OHTSUKA, Kunioki H ...
    2003 Volume 67 Issue 2 Pages 244-249
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      This study was done to examine the effects of corticosterone, a glucocorticoid, on Ca2+ uptake, proteolysis, and Ca2+ channels in primary cultures of chick muscle cells, to clarify the mechanism of glucocorticoid action on muscle proteolysis. Chick muscle cells were incubated for 24 h in a medium containing corticosterone (30 ng/ml) when the cells were confluent (6 days). To examine the contribution of Ca2+ channels, nifedipine, a Ca2+ channels antagonist, was used. Ca2+ uptake measured with 45CaCl2 was increased three-fold by corticosterone, with a peak at 12 h after the treatment started. The growth of the cells estimated from the protein content and creatine kinase activity was not affected by corticosterone. Proteolysis, evaluated with [3H]tyrosine as a label of the protein and Nτ-methylhistidine release, was unchanged by corticosterone. However, the amount of easily releasable myofilament as a measure of myofibrillar disassembly in the muscle cells was increased by corticosterone, and prevented by nifedipine. These results show that corticosterone increases Ca2+ uptake and starts myofibrillar protein breakdown.
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  • Kunihiko MORIYOSHI, Takashi OHMOTO, Tatsuhiko OHE, Kiyofumi SAKAI
    2003 Volume 67 Issue 2 Pages 250-257
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      An enzyme hydrolyzing β-1,4 bonds in cellulose acetate was purified 10.5-fold to electrophoretic homogeneity from a culture supernatant of Neisseria sicca SB, which assimilate cellulose acetate as the sole carbon and energy source. The enzyme was an endo-1,4-β-glucanase, to judge from the substrate specificity and hydrolysis products of cellooligosaccharides, we named it endo-1,4-β-glucanase I (EG I). Its molecular mass was 50 kDa, 9 kDa larger than EG II from this strain, and its isoelectric point was 5.0. Results of N-terminal and inner-peptide sequences of both enzymes, and a similarity search, suggested that EG I contained a carbohydrate-binding module at the N-terminus and that EG II lacked this module. The pH and temperature optima of EG I were 5.0-6.0 and 45°C. It hydrolyzed water-soluble cellulose acetate (degree of substitution, 0.88) and carboxymethyl cellulose. The Km and Vmax for these compounds were 0.296% and 1.29 μmol min-1 mg-1, and 0.448% and 13.6 μmol min-1 mg-1, respectively. Both glucanases and cellulose acetate esterase from this strain degraded water-insoluble cellulose acetate synergistically.
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  • Yoshiko IWAMOTO, Xu XU, Tadashi TAMURA, Tatsuya ODA, Tsuyoshi MURAMATS ...
    2003 Volume 67 Issue 2 Pages 258-263
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Enzymatically depolymerized guluronate and mannuronate oligomers were prepared from polyuronates with an alginate lyase from a Pseudoalteromonas sp., and their effects on mononuclear cells from human peripheral blood were examined. Conditioned medium prepared by the incubation of cells with an untreated polyuronate had little effect on growth of human leukemic U937 cells, but a medium prepared with depolymerized uronate oligomers inhibited their growth. Inhibition was greater in a medium prepared with guluronate oligomer than one prepared with mannuronate oligomer. The cytotoxic activity of the medium was heat-labile and nondialyzable. Apoptotic nuclear morphological changes and increased caspase-3-like activity were found in U937 cells treated with a medium prepared with depolymerized uronates. The medium prepared with purified tetra-guluronate and tetra-mannuronate also was cytotoxic; these effects were inhibited by antibodies to tumor necrosis factor-α. Our results suggested that enzymatically depolymerized guluronate and mannuronate oligomers induced the production of cytotoxic cytokines in human mononuclear cells, although the uronate polymers before depolymerization had no such activity.
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  • Yuko DOI, Byung Rho LEE, Masamichi IKEGUCHI, Yasunori OHOBA, Tadaaki I ...
    2003 Volume 67 Issue 2 Pages 264-270
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      The substrate specificities of deuterolysin, a 19-kDa zinc-protease (EC 3.4.24.39) from Aspergillus oryzae, were investigated at pH 9.0 with various fluorogenic acyl-peptide-4-methylcoumaryl-7-amides (peptide- MCAs). N-Butoxycarbonyl-Arg-Val-Arg-Arg-MCA was the best substrate for deuterolysin. We therefore measured its kinetic parameters. Deuterolysin had high activity toward the peptide bonds next to pairs of basic residues in calf thymus histone H4. The specificity of cobalt-substituted deuterolysin (Co-deuterolysin) for peptide-MCAs was similar to that of native deuterolysin. The CD spectrum of Co-deuterolysin was similar to that of the native deuterolysin. The metal coordination sphere of Co-deuterolysin was analyzed by Q-band (33.9570 GHz) electron paramagnetic resonance (EPR) spectroscopy. Using computer simulation of EPR, we found the g principal values to be gxx=5.20, gyy=4.75, and gzz=2.24; the metal center was a divalent cobalt ion in a high spin state.
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  • Hiroshi ASAO, Kazuya YOSHIDA, Yukio NISHI, Atsuhiko SHINMYO
    2003 Volume 67 Issue 2 Pages 271-277
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      The cucumber (Cucumis sativas) AAO1 gene (former name, Aso1) encodes an ascorbate oxidase that catalyzes the oxidation by molecular oxygen of ascorbic acid to dehydroascorbate. CsAAO1 mRNA concentrations rose rapidly after mechanical wounding of cucumbers. To study the wound-responsive expression of CsAAO1 in detail, we examined transgenic tobacco plants harboring a CsAAO1 promoter-β-glucuronidase fusion gene. CsAAO1 promoter activity in leaves of the tobacco was induced by wounding. Analysis of the regulatory properties of 5′-deleted promoter fragments showed that a putative wound-responsive cis-element (WRE) was located −736 to −707 bp from the translation initiation site. DNA binding factors that bound specifically to the putative WRE sequence were identified in tobacco nuclear extracts by gel retardation assays.
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  • Kei-ichi YOKOYAMA, Daisuke EJIMA, Yoshiko KITA, John S. PHILO, Tsutomu ...
    2003 Volume 67 Issue 2 Pages 291-294
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Recombinant microbial transglutaminase has been expressed in Escherichia coli as insoluble inclusion bodies. After we searched for refolding conditions, refolding of the protein could be done by first dilution of the unfolded enzyme in a buffer at pH 4.0, and then by titration of the pH from 4.0 to 6.0. CD analysis showed that a burst of secondary structure formation occurred within the dead time of the experiment and accounted for 75% of the signal change in the far UV CD, with little tertiary structure being formed. This burst was followed by slow rearrangement of the secondary structure accompanied by formation of tertiary structure. The secondary and tertiary structures of the final sample at pH 4.0, corresponding to the folding intermediate, were different from these structures at pH 6.0. Once the native structure was obtained, acidification of the native protein to pH 4.0 did not lead to a structure like that of the folding intermediate. Sedimentation velocity analysis showed that the folding intermediate had an expanded structure and contained no other structure species including large aggregates.
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  • Jin DING, Kazuo NAGAI, Je-Tae WOO
    2003 Volume 67 Issue 2 Pages 314-321
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      ST2 cells, a cloned stromal-cell line from mouse bone marrow have the phenotypes of osteoblasts and hematopoietic supporting cells, but little is known about the adipogenesis in this cell line. We found that treatment of ST2 cells with a cocktail, a combination of insulin, dexamethasone (DEX) and 3-isobutyl-1-methylxanthine (IBMX), induced adipocyte differentiation. The cells were adipocytic, as seen by the accumulation of triglycerides and with lipid droplets stained with Oil Red O. Expressions of the adipogenic transcriptional factors peroxisome-proliferator-activated receptor γ and CCAAT-enhancer binding protein α were stimulated, triggering the expression of the late adipocyte-specific marker α-glycerophosphate-3-dehydrogenase. Unlike another bone marrow stromal cell line PA6, ST2 cells responded to the adipogenic effects of insulin, as do the extramedullary preadipocytes 3T3-L1. Like PA6 and 3T3-L1 cells, adipogenesis in ST2 cells was inhibited by 1,25-dihydroxyvitamin D3, retinoic acid, tumour necrosis factor α, and transforming growth factor β. Therefore, ST2 cells can differentiate into osteoblasts, adipocytes, and hematopoietic supporting cells, in which the process of adipogenesis differs from that of bone marrow preadipocytes PA6, and resembles that of the extramedullary preadipocytes 3T3-L1.
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  • Keisuke SUZUKAWA, Takeshi YAMAGAMI, Takayuki OHNUMA, Hideki HIRAKAWA, ...
    2003 Volume 67 Issue 2 Pages 341-346
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      We expressed chitinase-1 (TBC-1) from tulip bulbs (Tulipa bakeri) in E. coli cells and used site-directed mutagenesis to identify amino acid residues essential for catalytic activity. Mutations at Glu-125 and Trp-251 completely abolished enzyme activity, and activity decreased with mutations at Asp-123 and Trp-172 when glycolchitin was the substrate. Activity changed with the mutations of Trp-251 to one of several amino acids with side-chains of little hydrophobicity, suggesting that hydrophobic interaction of Trp-251 is important for the activity. Molecular dynamics (MD) simulation analysis with hevamine as the model compound showed that the distance between Asp-123 and Glu-125 was extended by mutation of Trp-251. Kinetic studies of Trp-251-mutated chitinases confirmed these various phenomena. The results suggested that Glu-125 and Trp-251 are essential for enzyme activity and that Trp-251 had a direct role in ligand binding.
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  • Shigeo OTSUKI, Akira IKEDA, Tomomi SUNAKO, Shoshi MUTO, Junshi YAZAKI, ...
    2003 Volume 67 Issue 2 Pages 347-353
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      A cDNA encoding a predicted 15-kDa protein was earlier isolated from sugar-induced genes in rice embryos (Oryza sativa L.) by cDNA microarray analysis. Here we report that this cDNA encodes a novel Ca2+-binding protein, named OsSUR1 (for Oryza sativa sugar-up-regulated-1). The recombinant OsSUR1 protein expressed in Escherichia coli had 45Ca2+-binding activity. Northern analysis showed that the OsSUR1 gene was expressed mainly in the internodes of mature plants and in embryos at an early stage of germination. Expression of the OsSUR1 gene was induced by sugars that could serve as substrates of hexokinase, but expression was not repressed by Ca2+ signaling inhibitors, calmodulin antagonists and inhibitors of protein kinase or protein phosphatase. These results suggested that OsSUR1 gene expression was stimulated by a hexokinase-dependent pathway not mediated by Ca2+.
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  • Toshiaki TANABE, Kazuko MORINAGA, Tamo FUKAMIZO, Masaru MITSUTOMI
    2003 Volume 67 Issue 2 Pages 354-364
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      Streptomyces griseus HUT 6037 inducibly produced two chitosanases when grown on chitosan. To elucidate the mechanism of degradation of chitinous compound by this strain, chitosanases I and II of S. griseus HUT 6037 were purified and characterized. The purified enzymes had a molecular mass of 34 kDa. Their optimum pH was 5.7, and their optimum temperature was 60°C. They hydrolyzed not only partially deacetylated chitosan, but also carboxymethylcellulose. Time-dependent 1H-NMR spectra showing hydrolysis of (GlcN)6 by the chitosanases were obtained for identification of the anomeric form of the reaction products. Both chitosanases produced the β-form specifically, indicating that they were retaining enzymes. These enzymes catalyzed a glycosyltransfer reaction in the hydrolysis of chitooligosaccharides. The N-terminal and internal amino acid sequences of chitosanase II were identified. A PCR fragment corresponding to these amino acid sequences was used to screen a genomic library for the entire gene encoding chitosanase II. Sequencing of the choII gene showed an open reading frame encoding a protein with 359 amino acid residues. The deduced primary structure was similar to endoglucanase E-5 of Thermomonospora fusca, which enzyme belongs to family 5 of the glycosyl hydrolases. This is the first report of a family 5 chitosanase with transglycosylation activity.
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Biochemistry & Molecular Biology Notes
Food & Nutrition Science Regular Papers
  • Asako TAKENAKA, Hideyuki ANNAKA, Yuki KIMURA, Hisa AOKI, Kiharu IGARAS ...
    2003 Volume 67 Issue 2 Pages 278-283
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      The effect of a dietary soy protein isolate (SPI), soy peptide (PEP) and the amino acids in soy protein on paraquat (PQ)-induced oxidative stress was investigated in rats. In the first experiment, male Wistar rats were fed on experimental diets containing casein (CAS), SPI and PEP as nitrogen sources with or without 0.025% PQ. The reduced food intake and body weight gain of the rats fed with PQ was mitigated by either the SPI or PEP intake. Both SPI and PEP prevented the elevation of the serum TBARS concentration and tended to prevent the elevation of lung weight induced by PQ. In the second experiment, the rats were fed on diets containing an amino acid mixture resembling casein (CASAA) or soy protein (SPIAA) with or without PQ. The SPIAA intake did not affect the reduction of food intake and body weight gain, nor the elevation of lung weight and TBARS in the serum and liver induced by PQ. These results demonstrate that the intake of either dietary SPI or PEP, but not an amino acid mixture resembling soy protein, had the effect of reducing PQ-induced oxidative stress in rats.
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  • Tomoko SHIMAMURA, Atsuko TAKAMORI, Hiroyuki UKEDA, Masayoshi SAWAMURA
    2003 Volume 67 Issue 2 Pages 295-299
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      XTT (3′-{1-[(phenylamino)-carbonyl]-3,4-tetrazolium}-bis(methoxy-6-nitro)benzenesulfonic acid hydrate) was reduced by incubated glucosamine hydrochloride. The XTT reducibility by incubated glucosamine was linearly related with the DNA-breaking activity. In order to elucidate the reaction mechanism, the glucosamine derivatives formed during the incubation process were separated by HPLC, and the compound responsible for the reduction was analyzed. Among the incubated products, fructosazine and deoxyfructosazine were identified by LC-MS, FAB-MS, and 1H- and 13C-NMR. These products showed no XTT reducibility, but an unstable intermediate with a molecular weight of 322 displayed reducibility. Since the intermediate gave fructosazine by oxidation with XTT and was a precursor of deoxyfructosazine, we conclude that the intermediate could have been dihydrofructosazine. Therefore, the XTT reducibility by incubated glucosamine was based on dihydrofructosazine formed by the condensation of two molecules of glucosamine.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Xu-Fen ZHU, Xiao-Yun WU, Yun DAI
    2003 Volume 67 Issue 2 Pages 284-290
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      A species of bacterium with high chitosanase activity was isolated from soil samples in Haiyan City, China, and identified as an Acinetobacter species. This strain, named Acinetobacter sp. strain C-17, produced a chitosanase that was inducible and secreted into the medium. The optimal conditions for enzyme production were cells used to inoculate a medium containing 1% chitosan (pH 7.0) followed by culture at 30°C. The chitosanase activity reached 1.7 U/ml when strain C-17 was incubated in a 250-ml flask under the optimal conditions for 24 h, and reached 2.8 U/ml when cells were incubated in a 3-l fermentor. The optimal pH and temperature for hydrolysis of chitosanase were 7.0 and 36°C, respectively. The chitosanase activity was stable in the pH range of 5-8 and temperature range of 30-40°C. The chitosanase of the strain was extracted by zinc acetate and ammonium sulfate precipitation. The molecular mass was estimated to be 35.4 kDa by SDS-PAGE.
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  • Kenichi IWATA, Hideaki NOJIRI, Kentaro SHIMIZU, Takako YOSHIDA, Hirosh ...
    2003 Volume 67 Issue 2 Pages 300-307
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      The two-subunit meta-cleavage enzyme, 2′-aminobiphenyl-2,3-diol 1,2-dioxygenase (CarBaBb), from the carbazole degrader Pseudomonas resinovorans strain CA10 was purified to homogeneity from an Escherichia coli strain carrying the expression vector pUCA503, in which two copies of the carBaBb genes are tandemly linked. SDS-PAGE and gel filtration showed that CarB was a α2β2-heterotetrameric enzyme with subunit molecular masses of approximately 10,000 for CarBa and 29,000 for CarBb. The optimum pH for activity was 8.5 and that of temperature was 35°C. The CarB enzyme had a Km of 14 μM and a kcat/Km of 0.25 μM−1 s−1 for 2′-aminobiphenyl-2,3-diol, and the catalytic activities for biphenyl-type catecholic substrates were higher than those for monoaromatic catechol derivatives. The enzyme was originally isolated as a meta-cleavage enzyme for 2′-aminobiphenyl-2,3-diol involved in carbazole degradation, but the enzyme was highly specific for 2,3-dihydroxybiphenyl.
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  • Noriyuki DOUKYU, Hirokazu KUWAHARA, Rikizo AONO
    2003 Volume 67 Issue 2 Pages 334-340
    Published: 2003
    Released: June 27, 2003
    JOURNALS FREE ACCESS
      A bacterium that secreted cyclodextrin glucanotransferase (CGTase) in a medium overlaid with n-hexane was isolated and identified as Paenibacillus illinoisensis strain ST-12 K. The CGTase of the strain was purified from the culture supernatant. The molecular mass was 70 kDa. The enzyme was stable at pH 6 to 10 and active at pH 5.0 to 8.0. The optimum temperature at pH 7.0 was 65°C in the presence of 5 mM CaCl2. The enzyme produced mainly β-cyclodextrin. The total yield of α-, β-, and γ- cyclodextrins was increased 1.4-fold by the addition of ethanol. In particular, the yield of β-cyclodextrins in the presence of 10% (vol/vol) ethanol was 1.6-fold that without ethanol. The CGTase was stable and active in the presence of large amounts of various organic solvents.
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Microbiology & Fermentation Technology Note
Microbiology & Fermentation Technology Preliminary Communication
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