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Takao Mori

Bio: Takao Mori is an academic researcher. The author has contributed to research in topics: Immobilized enzyme & Aminoacylase. The author has an hindex of 19, co-authored 50 publications receiving 1356 citations.


Papers
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Journal ArticleDOI
TL;DR: Conditions for the gelation of k ‐carrageenan, which is a new polymer for immobilization of enzymes and microbial cells, were investigated in detail and immobilized preparations were easily tailor‐made to various shapes such as cube, bead, and membrane.
Abstract: Conditions for the gelation k-carrageenan, which is a new polymer for immobilization of enzymes and microbial cells, were investigated in detail k-Carrageenan was easily induced to gel by contact with metal ions, amines, amino acid derivatives, and water-miscible organic solvents By using this property of k-carrageenan, the immobilization of enzymes and microbial cells was investigated Several kinds of enzymes and microbial cells were easily immobilized with high enzyme activities Immobilized preparations were easily tailor-made to various shape such as cube, bead, and membrane The obtained immobilized preparations were stable, and columns packed with them were used for continuous enzyme reaction for a long period Their operational stabilities were enhanced by hardening with glutaraldehyde and hexamethylenediamine

154 citations

Journal ArticleDOI
TL;DR: Conditions for continuous production of L-aspartic acid from ammonium fumarate were investigated using a column packed with immobilized Escherichia coli cells entrapped in a polyacrylamide gel lattice and the immobilized cell column was very stable.
Abstract: By using a column packed with immobilized Escherichia coli cells entrapped in a polyacrylamide gel lattice, conditions for continuous production of L-aspartic acid from ammonium fumarate were investigated. When a solution of 1 M ammonium fumarate (pH 8.5) containing 1 mM Mg(2+) was passed through the immobilized cell column at a flow rate of space velocity (SV) = 0.8 at 37 C, the highest rate of reaction was attained. From the column effluents, L-aspartic acid was obtained in good yield. The immobilized cell column was very stable.

116 citations

Journal ArticleDOI
TL;DR: By employing a DEAE‐Sephadex–aminoacylase column, conditions for continuous optical resolution of acyl‐DL‐amino acids were investigated and the highest rate of hydrolysis of both substrates was attained.
Abstract: Conditions for the preparation of an aminoacylase column using DEAE‐Sephadex as a carrier were investigated. The aminoacylase column having the highest activity was obtained when 7500 μmoles/hr. of partially purified aminoacylase was charged into a column packed with 9 ml. of DEAE‐Sephadex A‐25 (bead type, hydroxy form). By employing a DEAE‐Sephadex–aminoacylase column, conditions for continuous optical resolution of acyl‐DL‐amino acids were investigated. When a solution of 0.2M acetyl‐DL‐methionine (pH 7.0, containing 5 × 10−4M Co2+) or 0.2M acetyl‐DL‐phenylalanine (pH 6.0, containing 5 × 10−4M Co2+) was passed through the aminoacylase column at the flow rate of SV = 2.5 or 2.0, respectively, at 50°C., the highest rate of hydrolysis of both substrates was attained. From the column effluents, enzymatically hydrolyzed L‐methionine and L‐phenylalanine were isolated in a good yield.

106 citations

Journal ArticleDOI
TL;DR: The reaction mechanism and decay behavior of aspartase activity for immobilized Escherichia coli cells were investigated by using a sectional packed column.
Abstract: The reaction mechanism and decay behavior of aspartase activity for immobilized Escherichia coli cells were investigated by using a sectional packed column. Reaction within the immobilized cell column proceeded at zero-order on substrate solutions ranging in concentration from 0.1 to 1.0M, and the initial reaction rate was found to be 1.556 X 10(-2) mol/min/liter of immobilized cells. The effect of temperature on the reaction rate constant was investigated. The Arrhenius plot was a straight line at temperatures below 43 degrees C, and the activation energy for immobilized cells was calculated to be 12.36 kcal/mol. Aspartase activity in the immobilized cell column decayed exponentially and uniformly in all sections of a column. Its half-life was approximately 120 days. The rate of formation of L-aspartic acid was shown to be independent of column dimensions.

97 citations

Book ChapterDOI
TL;DR: Various immobilization methods were investigated, and relatively active and stable immobilized aminoacylases were obtained by ionic binding to DEAE-Sephadex, covalent binding to iodoacetylcellulose, and entrapping into polyacrylamide gel lattices.
Abstract: Publisher Summary This chapter discusses the preparation, the enzymic properties, and the industrial application of immobilized aminoacylases. Various immobilization methods were investigated, and relatively active and stable immobilized aminoacylases were obtained by ionic binding to DEAE-Sephadex, covalent binding to iodoacetylcellulose, and entrapping into polyacrylamide gel lattices. Typical immobilization methods for mold aminoacylase are described in the chapter. To store the immobilized preparation for a long period or to measure its enzyme activity, it is suspended in 2.5 liters of distilled water and lyophilized. Using this procedure, 106 g of DEAE-Sephadexaminoacylase is obtained. The activity of the preparation is about 700 moles/hr per gram of preparation under standard assay conditions. The optimum pH of the DEAE-Sephadex-aminoacylase shifts about 0.5–1.0 pH unit more to the acid side than that of the native enzyme. This shift may be explained by the redistribution of hydrogen ions between the positively charged DEAE-Sephadex and the surrounding aqueous medium. This shift is also found for polyacrylamide-aminoacylase, but the reason is not clear in this ease.

89 citations


Cited by
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Journal ArticleDOI
TL;DR: This review evaluates the merits and limitations of the two common encapsulation techniques, namely extrusion and emulsion, to encapsulate the probiotics for their use in the fermented and other dairy products.

775 citations

Journal ArticleDOI

581 citations

Journal ArticleDOI
TL;DR: A review examines many of the scientific and technical aspects involved in using immobilized microbial cells in environmental applications, with a particular focus on cells encapsulated in biopolymer gels.
Abstract: Immobilized microbial cells have been used extensively in various industrial and scientific endeavours. However, immobilized cells have not been used widely for environmental applications. This review examines many of the scientific and technical aspects involved in using immobilized microbial cells in environmental applications, with a particular focus on cells encapsulated in biopolymer gels. Some advantages and limitations of using immobilized cells in bioreactor studies are also discussed.

503 citations

Book ChapterDOI
TL;DR: The intention of this paper is to outline the common immobilization methods and reaction technologies to facilitate proper applications of immobilized enzymes.
Abstract: Immobilized enzymes are used in organic syntheses to fully exploit the technical and economical advantages of biocatalysts based on isolated enzymes. Immobilization enables the separation of the enzyme catalyst easily from the reaction mixture, and can lower the costs of enzymes dramatically. This is true for immobilized enzyme preparations that provide a well-balanced overall performance, based on reasonable immobilization yields, low mass transfer limitations, and high operational stability. There are many methods available for immobilization which span from binding on prefabricated carrier materials to incorporation into in situ prepared carriers. Operative binding forces vary between weak multiple adsorptive interactions and single attachments through strong covalent binding.Which of the methods is the most appropriate is usually a matter of the desired applications. It is therefore the intention of this paper to outline the common immobilization methods and reaction technologies to facilitate proper applications of immobilized enzymes.

490 citations

Book ChapterDOI
01 Jan 1991

447 citations