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Hlroshi Ooshima Yoshiharu Yamane Yozo Nakamura Hideki Sakashita Masayuki Azuma Jyoji Kato 《Applied biochemistry and biotechnology》1998,73(1):51-58
A highly efficient spray-cycle reactor for oxygen supply was developed. A typical arrangement of the reactor consists of a
spray column fitted with a nozzle and a coaxal tube, and a reservoir vessel. The culture broth was circulated between the
column and vessel by a peristaltic pump. The volumetric oxygen-transfer coefficient, k1a was evaluated as a parameter for oxygen supply. The liquid circulation rate in the spraycycle reactor was represented in
terms of the number of circulations. The k1a value increased as the number of circulations increased, reaching 208 h-1 at 4.4 min-1 of circulation numbers. This value was 1.8 times higher than that in a 1500-mL stirred-tank reactor under the agitation of
20.7g and the aeration of 1.0 volume per min.
The spray-cycle reactor was applied to riboflavin production by an aerobic microorganism. The riboflavin production increased
as k1a values increased and the maximal riboflavin production was 161 mg/L at 208 h-1 of k1a. These results suggest that the spray-cycle reactor is useful to oxygen-demanding fermentation because of the high k1a value in comparison with the stirred-tank reactor. 相似文献
23.
The rhodium-catalyzed reaction of Sb-aryl-1,5-azastibocines with alpha,beta-unsaturated ketones and esters is described. Exclusive formation of 1,4-conjugate adduct was achieved in aqueous NMP (N-methyl-2-pyrrolidinone) in the presence of 5 mol% of [RhCl(cod)](2), and no formation of Heck adduct was observed in this condition. Reactions with various enones and enoates were also demonstrated to prove generality of the 1,4-conjugate addition. 相似文献
24.
A molecular-dynamics method is applied to study the particle correlation in superionic conductor α-AgI. It is found that there
is a close connection between the particle correlation λi,j (i,j=I or Ag) and the radial distribution function. The values of λII and λIAg at the nearest neighbor site are below 0.3. The values of λAgAg at the nearest neighbor site and λII at the next nearest neighbor site are about 1/2 ≈ 1/3 of it of λII (and λIAg) at the nearest neighbor site. 相似文献
25.
Yoshihito Ohtsuka Yuichi Takaku Jyoji Kimura Shun'ichi Hisamatsu Jiro Inaba 《Analytical sciences》2005,21(3):205-208
This paper describes our development of a rapid on-line column/ID-ICP-MS technique for the analysis of plutonium (Pu) in environmental samples using an UTEVA extraction chromatograph resin (UTEVA resin) column. It took only 40 min to separate and measure Pu in the sample solution, including the time for conditioning the resin column for the next analysis. In our method, Pu in a 3 M nitric acid solution was fed to the UTEVA resin, and then eluted from the resin by reducing Pu to Pu(III) with 3 M nitric acid mixed with 0.01 M ascorbic acid after washing the resin. The outflow from the resin column was directly introduced to an ICP-MS system. The low concentration of ascorbic acid and the small volume of the eluting solution (0.6 mL) made successive stable analysis possible without any skimmer cone clogging. The chemical recovery of Pu during column operation was 70%, and typical lower detection limits for 239Pu, 240Pu and 242Pu were 9.2, 4.3 and 7.5 fg (21, 36 and 1.1 microBq), respectively. We analyzed five international standard materials for Pu, and obtained good results. 相似文献
26.
Novel, enantiomerically pure organoantimony compounds having a C-chiral amine moiety, (S)-(alpha-methyl-2-di-p-tolylstibanobenzyl)dimethylamine [AMSb] (2) and its (eta(6)-arene)chromium complex [AMSb-Cr(CO)(3)] (4), were prepared from common (S)-(alpha-methylbenzyl)dimethylamine (1) via its ortho-lithiated intermediates in short steps. The catalytic activity and enantioselectivity of the ligands 2 and 4 for asymmetric reaction are evaluated, and the optically active (eta(6)-arene)chromium complex 4 has been shown to be an effective ligand for rhodium-catalyzed asymmetric hydrosilylation of ketones. 相似文献
27.
Novel base-free Suzuki-type cross-coupling reaction by the use of triarylantimony diacetates and arylboronic acids in the presence of Pd(PPh3)4 catalyst led to the formation of biaryl derivatives in moderate to excellent yields. The reaction is applicable to a variety of arylboronic acids bearing base-sensitive functional groups. 相似文献
28.
Hiroshi Ooshima Masahiro Kurakake Jyoji Kato Yoshio Harano 《Applied biochemistry and biotechnology》1991,31(3):253-266
Hydrolysis of pure cellulose Avicel has been carried out, using Meicelase from Trichoderma viride, where the enzymatic activity of cellulase adsorbed on cellulose and its changes during the hydrolysis were investigated. A rapid drop of the hydrolysis rate during the reaction, that is always observed in enzymatic hydrolysis of cellulose, could be explained by a decline of specific activity of adsorbed enzyme, and it was implied that the decline results from a loss of synergistic action between endoglucanase and exoglucanase. An empirical equation expresses the change of hydrolysis rate during the reaction and also shows that the change of the hydrolysis rate is caused by the decline of the specific enzymatic activity of adsorbed enzyme. 相似文献
29.
Weiwei Qin Shuji Yasuike Naoki Kakusawa Masatoshi Kawahata Jyoji Kurita 《Journal of organometallic chemistry》2008,693(1):109-116
The reaction of triarylantimony diacetates (6) with organoboron reagents (9) in the presence of Pd(PPh3)4 led to the formation of cross-coupling products, biaryls (10, 12 and 14-17), in moderate to excellent yields under mild conditions without any base. Similar reaction of 6 with triarylbismuthanes (18) also gave the corresponding cross-coupling products. Single crystal X-ray analysis of tri(p-tolyl)antimony diacetate (6b) and tris(p-trifluoromethylphenyl)antimony diacetate (6e) revealed the geometry of both central antimony atoms being intermediate between trigonal bipyramidal and pentagonal bipyramidal arrangement with intramolecular coordination between the antimony and two carbonyl oxygen atoms with cis orientation. 相似文献