Ichiro Chibata
FermentationMutantOrganic chemistryEnzymeChemistryThreonineSerratia marcescensIsoleucineImmobilized enzymeChromatographyAmino acidBacteriaYield (chemistry)Escherichia coliBiochemistryStereochemistryBiologyResolution (mass spectrometry)MicrobiologyHydrolysis
Publications 287
Existing methods for prepaiing pure L-leucine from protein hydrolysates are unsatisfactory, especially when L-leucine, isoleucine-free, is required in high purity. Using a commercial crude leucine containing 73% of L-leucine, 10% of L-isoleucine and other impurities, the preparation of pure L-leucine was investigated. As a result, the fractional crystallisation of the sulphonates of L-leucine with benzenesulphonic acid and p-toluenesulphonic acid was found to be very effective for the purificati...
3 CitationsSource
#1David H. G. Crout (University of Exeter)H-Index: 18
#2Maria Virgínia Mendes Gregório (University of Minho)H-Index: 1
Last. Ichiro ChibataH-Index: 52
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1 dl[3-2H]Threonine, l-[3-2H]threonine, (2RS,3S)-2-amino[3-2H1] butanoic acid, (2RS,3S) 2-amino[3-3H1]butanoic acid and dl-2-amino[3-14C]butanoic acid were synthesised. 2 l-[3-2-H]Threonine was converted into l-[4-2H1]isoleucine by Serratia marcescens strain IHr313. 3 (2RS,3S)-2-Amino[3-2-H1]butanoic acid was converted into l-[4-4-H1]isoleucine by S. marcescens strain 149. 4 Analysis by 220-MHz NMR spectroscopy of the labelled l-isoleucine produced showed that the same diastereotopic hydrogen at...
18 CitationsSource
#1Yoko FujiwaraH-Index: 24
#2Megumi OtsukaH-Index: 14
Last. Yoshinori ItokawaH-Index: 25
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ビタミンC測定法, および血中の総ビタミンC値の基準値 (参考値) を検討した。健康な女子大生ボランティア54人に, 3日間の食事調査の後, 採血し, ビタミンCを1日200mg含む一定の試験食を3日間供した。3日後に再び採血を行い, 得られた血漿のビタミンC濃度を測定した。測定は3カ所の施設でHPLC法 (お茶の水女子大学, テイジンエスアールラボ) およびアスコルビン酸オキシダーゼ法 (東邦大学) を用いて行い, 各施設での測定値の比較も行った。総ビタミンC濃度の試験食摂取前値と後値では平均値に有意な差はみられないが, 後値ではばらつき (標準偏差) が小さくなり, ビタミンCの一定量摂取が, 血中濃度に影響を与えることが示唆された。前値でビタミンC濃度が低値にあった学生では, ビタミンCを1日200mg, 3日間摂取することで, 血中濃度は0.62mg/dL以上の範囲に入った。異なる測定方法による施設間差は認められず, 従って, 統計的に95%の信頼範囲から血中総ビタミンC濃度の基準値は0.70-1.38mg/dL (HPLC/ECD法) となった。この値は栄養所要量算出の際に基...
4 CitationsSource
Un appareillage particulier annexe a un bioreacteur enzymatique permet d'eliminer le produit forme au cours de la reaction et est responsable en partie de la destruction des enzymes immobilisees. Pendant le procede, le produit synthetise est evacue du bioreacteur, et cristallise a froid dans un reservoir independant. Cette technologie est appliquee a la conversion du fumarate de calcium en malate de calcium, par la fumarase de cellules immobilisees de Brevibacterium flavum
7 CitationsSource
#1Kousaku Murata (Kyoto University)H-Index: 59
#2Tomofumi UchidaH-Index: 7
Last. Ichiro ChibataH-Index: 52
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The distribution and some properties of polyphosphate kinase, that catalyzes the formation of polyphosphate from ATP, were investigated. High enzyme activity was found in Alcaligenes faecalis, Brevibacterium ammoniagenes, Escherichia coli, Micrococuss lysodeikticus and Pseudomonas aeruginosa. The enzyme required Mg2+ for maximum activity and was activated by basic proteins, polyamines and phosphate polymers of low molecular weight. The enzyme from E. coli B could catalyze the reverse reaction, a...
32 CitationsSource
A practical method for the production of D-p-hydroxyphenylglycine, useful as a starting material for preparing semisynthetic penicillins or cephalosporins, has been developed. The diastereomeric salts of DL-p-hydroxyphenylglycine with (+)-1-phenylethanesulfonic acid as a resolving agent, were efficiently resolved into less soluble D-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate [D-HPG·(+)-PES] and soluble L-HPG·(+)-PES by the fractional crystallization of its salts in aqueous solution. The ...
9 CitationsSource
2 CitationsSource
Optically active 1-phenylethanesulfonic acid was found to be an efficient resolving agent for the optical resolution and asymmetric transformation of DL-p-hydroxyphenylglycine. When DL-p-hydroxyphenylglycine was resolved by the fractional crystallization of its diastereomeric salt with (+)-1-phenylethanesulfonic acid, less soluble D-p-hydroxyphenylglycine (+)-1-phenylethanesulfonate [D-HPG·(+)-PES] was obtained in a good yield. Soluble L-HPG·(+)-PES was easily epimerized into DL-HPG·(+)-PES by h...
18 CitationsSource
#1Ichiro ChibataH-Index: 52
#2Tetsuya TosaH-Index: 45
Last. Isao TakataH-Index: 13
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Publisher Summary This chapter describes the production of L-malic acid by immobilized microbial cells. As the immobilized cells have an activity that forms succinic acid as a by-product, succinic acid and unconverted fumaric acid accumulate in the reaction mixture. Although fumaric acid can be easily precipitated by acidifying the reaction mixture with hydrochloric acid, it is very difficult to separate succinic acid from L-malic acid. The key step to a successful process, therefore, is to prev...
17 CitationsSource
#1Ichiro ChibataH-Index: 52
#2Tetsuya TosaH-Index: 45
Last. Satoru TakamatsuH-Index: 8
view all 3 authors...
Publisher Summary This chapter describes the method of preparation of immobilized microbial cells suitable for industrial application and the bioreactors used for sequential enzyme reactions. L-Alanine is used as a component of amino acid infusion and as a food additive because of its good taste. It has traditionally been produced from solid L-aspartic acid by a batch enzymatic method using the activity of L-aspartate β-decarboxylase of intact Pseudomonas dacunhae cells. In turn, L-aspartic acid...
10 CitationsSource