研究者詳細 - 今村　維克

Enzymatic Synthesis of Non-proteinaceous Amino Acids Catalyzed by Cysteine Synthase Coupled with Acetyl-CoA Regeneration

異なる金属表面への種々の有機物質の吸着挙動の比較

長安武司, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 292 - 292 2005年

Zhao Chunhui, Imanaka Hiroyuki, Imamura Koreyoshi, Nakanishi Kazuhiro

化学工学会研究発表講演要旨集 2005 271 - 271 2005年

金属表面に吸着した各種タンパク質のH2O2-電気分解処理における脱離特性と脱離促進因子

今村維克, 尾下学, 岩井真澄, 金本知明, 今中洋行, 中西一弘

化学工学会研究発表講演要旨集 2005 294 - 294 2005年

放線菌 Streptomyces mobaraensis 由来新規アシラーゼの精製・特性解析および合成反応

是石真友子, 川崎涼子, 今中洋行, 今村維克, 中西一弘, 丹尾式希

化学工学会研究発表講演要旨集 2005 270 - 270 2005年

膜面液体培養法を用いた遺伝子組換え麹カビによるNuclease S1生産

森田正和, 安達昇, 奥村敦, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 242 - 242 2005年

温度走査フーリエ変換赤外分光分析による糖-高分子複合アモルファスマトリクスにおける分子間相互作用の解析

大山健一, 谷加寿子, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005 293 - 293 2005年

ポリスチレン親和性ペプチド融合タンパク質の吸着特性とその応用

徳永安秀, 熊田陽一, 今石大輔, 今中洋行, 今村維克, 崎山高明, 中西一弘

化学工学会研究発表講演要旨集 2005f 311 - 311 2005年

Analysis of Differential Gene Expression of Aspergillus oryzae in Membrane-Surface Liquid Culture and Shaking Flask Culture by Subtractive Hybridization

Feng Bin, 森田正和, 今中洋行, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005f 294 - 294 2005年

2'-デオキシアデノシン5'-三リン酸(dATP)の酵素合成に関する反応工学的研究

今中洋行, 矢野慎太郎, 今村維克, 中西一弘

化学工学会研究発表講演要旨集 2005f 214 - 214 2005年

Characteristics of alpha-glucosidase production from recombinant Aspergillus oryzae by membrane-surface liquid culture in comparison with various cultivation methods 査読

M Morita, H Shimamura, N Ishida, K Imamura, T Sakiyama, K Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 98 ( 3 ) 200 - 206 2004年9月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

alpha-Glucosidase was produced using recombinant Aspergillus oryzae by membrane-surface liquid culture (MSLC), a method previously developed by the authors and the results compared with other methods, including shaking flask culture (SFC), agar-plate culture (APC), culture on urethane sponge supports (USC), and liquid surface culture (LSC) to determine possible reasons for the advantageous features of MSLC. When yeast extract was used as a nitrogen source, the amount of enzyme produced by MSLC was 5 or more times higher than those for SFC and LSC, but similar to that using APC. Enzyme production in USC was slightly lower than in MSLC and APC. Cell growth was similar irrespective of the cultivation method used. When NaNO3, a typical inorganic nitrogen source was used, enzyme production in all the cultures was lower than that using yeast extract. However, even using NaNO3, the amount of the enzyme produced by MSLC was 8 to 20 times higher than those by SFC, APC, USC, and LSC. Although Cell growth using NaNO3 was similar to that for yeast extract in MSLC, it was markedly decreased in SFC, APC, and LSC. The reason for the difference in enzyme productivity for various cultivation methods using yeast extract and NaNO3 as a nitrogen source is discussed, on the basis of the experimental findings. The role of the oxygen transfer effect and gene expression levels in enzyme production were also examined.

DOI： 10.1016/S1389-1723(04)00266-X

Production of nonproteinaceous amino acids using recombinant Escherichia coli cells expressing cysteine synthase and related enzymes with or without the secretion of O-acetyl-L-serine 査読

CH Zhao, K Ohno, K Sogoh, K Imamura, T Sakiyama, K Nakanishi

JOURNAL OF BIOSCIENCE AND BIOENGINEERING 97 ( 5 ) 322 - 328 2004年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：SOC BIOSCIENCE BIOENGINEERING JAPAN

beta-(Pyrazol-1-yl)-L-alanine (beta-PA), a model nonproteinaceous amino acid, was specifically synthesized by two methods using recombinant Escherichia coli cells that express cysteine synthase, comprising serine acetyltransferase (SAT) and O-acetylserine sulfhydrylase-A (OASS-A) and related enzymes from E. coli. In the first method (method A), recombinant cells that express wildtype SAT, OASS-A, acetate kinase (AK), and phosphotransacetylase (PTA) showed the highest beta-PA production. beta-PA was produced at 140 mM from 200 MM L-serine and 200 mM pyrazole under optimum conditions. Using the cells expressing SATDeltaC20 (truncated SAT), OASS-A, AK, and PTA, beta-PA was produced at a level of only 80 mM, whereas O-acetyl-serine (OAS) was found to be secreted into the broth. Under optimum conditions, OAS accumulated at levels of around 105 mM from 300 mM L-serine. Thus, in the second method (method B), the secreted OAS was used as the substrate for the syntheses of beta-PA and beta-(triazol-1-yl)-L-alanine (beta-TA). The OAS that accumulated in the broth was efficiently converted to beta-PA and beta-TA at levels of around 90 mM from 105 mM OAS using free OASS-A. In both methods A and B, the addition of glucose was essential for the efficient production of beta-PA and OAS, respectively.

DOI： 10.1016/S1389-1723(04)70213-3

Factors Affecting Performance of Cleaning Technique for Metal Surfaces Based on Electrolysis of Hydrogen Peroxide, H2O2-electrolysis 査読

Koreyoshi Imamura

nihon shokuhin kougakukaishi (japan journal of food engineering) 9 ( 4 ) 229 - 238 2004年

記述言語：英語掲載種別：研究論文（学術雑誌）

We have developed a novel technique for removing organic soilings from metal surfaces using hydroxy radicals (·OH). In the cleaning system, a metal surface fouled with organic soilings is made to contact with an aqueous solution containing hydrogen peroxide and supporting electrolyte. A slightly negative potential is then applied into the metal. The ·OHs, which are generated by the electrolysis of hydrogen peroxide (H2O2+e--ē·OH+OH”) on the metal surface, effectively attack and subsequently remove the adsorbed organic soils. In this study, the removal behavior of model organic soilings (protein) during the H2O2-electrolysis cleaning using different types and concentrations of supporting electrolyte was investigated. The presence of ammonium compounds and potassium phosphate led to marked increase in the removal rate. The influences of the types of metal substrate and adsorbed material on the removal behavior were also investigated, which suggested that the adsorption state of organic soiling on a metal surface strongly affect the removal characteristics. Furthermore, the removal rates in the presence of various organic coexisting materials were investigated. It was found that the removal rate constant was only slightly lowered in many cases. © 2008, Japan Society for Food Engineering. All rights reserved.

DOI： 10.11301/jsfe2000.9.229

Scopus

Removal Behavior of Protein Adsorbed on Metal Surface by H₂O₂-Electrolysis Treatment

Imamura Koreyoshi, Watanabe Ippei, Aramoto Yumi, Sakiyama Takaharu, Nakanishi Kazuhiro

アジア・太平洋化学工学会議発表論文要旨集 2004 353 - 353 2004年

記述言語：英語出版者・発行元：公益社団法人化学工学会

A novel method for generating hydroxyl radicals, ·OH, was developed, by applying slightly negative electric potentials (-0.2 ∼ -0.8 V vs Ag/AgCl) to the surface of a metal in contact with a hydrogen peroxide solution containing a supporting electrolyte. Namely, ·OH radicals are generated at the surface by the electrolysis of hydrogen peroxide according to the equation, H₂O₂ + e- -> ·OH + OH-. In this study, the kinetics of the removal of a model proteinaceous soiling (ß-lactoglobulin, ß-Lg) adsorbed to a stainless steel surface by the H₂O₂-electrolysis treatment were investigated. The rate of removal of the adsorbed ß-Lg from the stainless steel surface during the treatment was monitored in situ by ellipsometry, and the dependencies of the removal rate on H₂O₂ concentration, the electric potential applied to the surface, and the concentration and type of supporting electrolyte were examined.

DOI： 10.11491/apcche.2004.0.353.0

CiNii Article

Production of Non-Proteinaceous Amino Acids using Recombinant E. coli Cells

Nakanishi Kazuhiro, Zhao Chunhui, Imamura Koreyoshi, Ohno Katsuhiro

アジア・太平洋化学工学会議発表論文要旨集 2004 815 - 815 2004年

記述言語：英語出版者・発行元：公益社団法人化学工学会

β-(Pyrazol-1-yl)-L-alanine (β-pyrazole-L-Ala; β-PA), a model non-proteinaceous amino acid was synthesized using recombinant Escherichia coli cells that express cysteine synthase and enzymes that regenerate acetyl-CoA. In Method A, β-PA was synthesized from L-Ser and pyrazole using recombinant cells that express wild-type serine acetyltransferase (SAT), O-acetylserine sulfhydrylase-A (OASS-A), acetate kinase (AK), and phosphotransacetylase (PTA). Under the optimized condition, β-PA was produced at 140 mM from 200 mM L-Ser and 200 mM pyrazole. On the other hand, in Method B, O-acetyl-L-serine (OAS) was secreted into the broth, using the cells that express SATΔC20 (truncated SAT), OASS-A, AK, and PTA. Under optimized conditions OAS accumulated in the broth at levels of around 100 mM. The secreted OAS was efficiently converted to β-PA at levels of around 90 mM from 105 mM OAS using free OASS-A. In both Methods A and B, the addition of glucose was essential for the efficient production of β-PA and OAS, respectively.

DOI： 10.11491/apcche.2004.0.815.0

CiNii Article

Effects of water activity and lipid addition on secondary structure of zein in powder systems 査読

Y Mizutani, Y Matsumura, K Imamura, K Nakanishi, T Mori

JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 51 ( 1 ) 229 - 235 2003年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER CHEMICAL SOC

The effects of water activity (A(w)) and lipid addition on the secondary structure of powdery zein were investigated using Fourier transform infrared spectroscopy. Two fatty acid esters, i.e., the linolenic and eicosapentaenoic acid ethyl esters (LAE and EPE), were mixed with the zein powder. The powders were stored in the "dry" state (with silica gel) and the "humid" state (A(w) = 0.9). The powdery zein without the lipids was shown to have a high content of the intermolecular hydrogen-bonded beta-sheet in the "dry" state, indicating the presence of protein aggregates. An increase in AW induced a decrease in this beta-sheet, concomitant with increases in the alpha-helix and beta-turn structures. The addition of LAE caused decreases in the alpha-helix and intermolecular hydrogen-bonded beta-sheet of zein when the powder was stored in the "humid" state, suggesting the strong interaction of LAE and zein molecules. However, LAE did not affect the secondary structure of zein in the "dry" state. The addition of EPE hardly influenced the secondary structure of zein, irrespective of A(w). These results are discussed in relation to the antioxidative activity of zein in the powder system, which had studied previously.

DOI： 10.1021/jf0205007