Effects of temperature and agitation rate on the formation of conjugated linoleic acids in soybean oil during hydrogenation process.     

M O Jung  S H Yoon  M Y Jung 《Journal of agricultural and food chemistry》2001,49(6):3010-3016

The effects of hydrogen temperature and agitation rate on the formation of total conjugated linoleic acids (CLA) and CLA isomers were studied during hydrogenation with a selective Ni catalyst. The CLA isomers were identified by using a 100-m cyano-capillary column gas chromatograph and a silver ion-impregnated HPLC. Reaction temperature and agitation rate greatly affected the quantities of total CLA and individual CLA isomers, and the time to reach the maximum quantity of CLA in the partially hydrogenated soybean oil. As the hydrogenation temperature increased, the maximum quantity of CLA in soybean oil increased, but the time to reach the maximum CLA content decreased. By increasing the hydrogenation temperature from 170 to 210 degrees C, the quantity of CLA obtained was about 2.6 times higher. As the agitation rate decreased, the CLA formation in soybean oil increased, and the time to reach the maximum CLA content also increased. The maximum CLA contents in soybean oil obtained during hydrogenation at 210 degrees C with agitation rates of 300, 500, and 700 rpm were 162.82, 108.62, and 66.15 mg total CLA/g oil, respectively. The present data showed that it is possible to produce high-CLA-content soybean oil without major modification of fatty acid composition by short-time (10 min) selective hydrogenation under high temperature and low agitation rate conditions.  相似文献   

Differences in polymer formation through disulfide bonding of recombinant light meromyosin between white croaker and walleye pollack and their possible relation to species specific differences in thermal unfolding     

Fukushima H  Yoon SH  Watabe S 《Journal of agricultural and food chemistry》2003,51(14):4089-4095

Fast skeletal light meromyosins (LMMs) of white croaker and walleye pollack were prepared in our expression system using Escherichia coli and determined for their polymer-forming ability and thermodynamic properties by using sodium dodecyl sulfate polyacrylamide gel electrophoresis and differential scanning calorimetry (DSC), respectively. White croaker LMM formed dimer by heating at 80 degrees C and showed only a single peak at 32.1 degrees C of temperature transition in DSC. On the other hand, walleye pollack LMM hardly formed polymer and showed four peaks at 27.7, 30.5, 35.8, and 43.9 degrees C. When Cys525 of white croaker LMM was replaced by alanine, this point-mutated LMM showed no change in its DSC profile but formed no dimer upon heating, suggesting a possible role of Cys525 in dimer formation. On the other hand, walleye pollack LMM where Cys491 was substituted by alanine changed its DSC profile, showing four peaks at 27.9, 29.1, 38.4, and 43.9 degrees C. However, this point-mutated LMM formed no dimer upon heating as in the case of native LMM. These results suggest that cysteine residue(s) participates in thermal gel formation of LMM when it locates in a suitable position of the sequence.  相似文献   

Levan fructotransferase from Arthrobacter oxydans J17-21 catalyzes the formation of the di-D-fructose dianhydride IV from levan     

Jang KH  Ryu EJ  Park BS  Song KB  Kang SA  Kim CH  Uhm TB  Park YI  Rhee SK 《Journal of agricultural and food chemistry》2003,51(9):2632-2636

A new levan fructotransferase (LFTase) isolated from Arthrobacter oxydans J17-21 was characterized for the production of difructose dianhydride IV (DFA IV). LFTase was purified to apparent homogeneity by Q-Sepharose ion exchange chromatography, Mono-Q HR 5/5 column chromatography, and gel permeation chromatography. The enzyme had an apparent molecular mass of 54000 Da. The optimum pH for the enzyme-catalyzed reaction was pH 6.5, and the optimum temperature was observed at 45 degrees C. The LFTase was activated by the presence of CaCl(2) and EDTA-2Na but inhibited strongly by MnCl(2) and CuSO(4) at 1 mM and completely by FeSO(4) and Ag(2)SO(4) at 1 mM. A bacterial levan from Zymomonas mobilis was incubated with an LFTase; final conversion yield from the levan to DFA IV was 35%. Neither inulin, levanbiose, sucrose, dextran, nor starch was hydrolyzed by LFTase. DFA IV was very stable at acidic pH and high temperature, thus indicating that DFA IV may be suitable for the food industry and related areas.  相似文献   

Evaluation of Air Injection and Extraction Tests at a Petroleum Contaminated Site,Korea     

Lee  C. H.  Lee  J. Y.  Jang  W. Y.  Jeon  Y. H.  Lee  K. K. 《Water, air, and soil pollution》2002,135(1-4):65-91

Air injection and extraction tests were conducted at a site where soils and groundwater were contaminated by petroleum hydrocarbons, mainly composed of TEX (toluene, ethylbenzene,and xylene). Storage tanks of petroleum hydrocarbons located less than 20 m away from the center of the test site were suspected to be the contamination source. Six injection/extraction wells and 21 monitoring wells were installed to evaluate performance and radius of influence with respect tosoil vapor extraction and air injection. Effective radius ofinfluence of the air injection tests based on pressure changes ranged from 3.3 to 10.5 m. Soil gas pressures, concentrationsof O₂, CH₄ and CO₂, and temperatures were measured during the tests. Air permeability and radii of influence with respect to gas pressure and oxygen supply by air injection were estimated. Dynamic changes in the concentrations of O₂, CH₄ and CO₂ gases and temperature around the extent of their ranges were detected asair was injected. We evaluated extensively the variations ofthe geochemical parameters that were indicative of active microbial degradation in this study.  相似文献   

Therapeutic effect of hyaluronic acid on experimental osteoarthrosis of ovine temporomandibular joint.   总被引：3，自引：0，他引：3  

C H Kim  B J Lee  J Yoon  K M Seo  J H Park  J W Lee  E S Cho  J J Hong  Y S Lee  J H Park 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2001,63(10):1083-1089

A symptomatic relief by hyaluronic acid (HA, MW: 3.5 x 10(6)), which is synthesized by Streptococcus spp, was investigated in experimental ovine osteoarthrosis. Bilateral osteoarthrosis (OA) of the temporo-mandibular joints (TMJs) was induced by perforating discs and by scrapping subchondral condylar surface. HA was intra-articularly injected into the left joints of 6 sheep on 7, 10, 14, 17 and 21 days after the operation and physiological saline as the control was injected into the contralateral (right) joints on the same day. Three sheep were killed at I month post-operation (MPO) and the remaining three sheep were killed at 3 MPO. Various responses such as proliferation of fibrous tissue, denudation, erosion, osteophyte formation, subcortical cyst formation and ankylosis were observed radiographically and histopathologically. The treatment of HA ameliorated the degenerative changes and lowered the osteoarthrotic score in the left joints at I MPO (9.96 vs 5.81) and 3 MPO (10.86 vs 5.29) compared to the right joints. These results indicate that a repeated intra-articular injection of HA inhibits the progression of OA in ovine TMJs by inducing the development of articular cartilage and by reducing the proliferation of fibrotic tissue.  相似文献   

Canine urinary tract infections: a comparison of in vitro antimicrobial susceptibility test results and response to oral therapy with ampicillin or with trimethoprim-sulfa   总被引：1，自引：0，他引：1  

G V Ling  P J Rohrich  A L Ruby  D L Johnson  S S Jang 《Journal of the American Veterinary Medical Association》1984,185(3):277-281

In vitro susceptibility testing correctly predicted the outcome of ampicillin therapy in all 56 urinary tract infections (UTI) caused by coagulase-positive staphylococci (Staphylococcus aureus and S intermedius), in all 26 UTI caused by Proteus mirabilis, in 38 of 44 UTI caused by Escherichia coli, in 29 of 31 UTI caused by Streptococcus spp, in 8 of 10 UTI caused by Klebsiella pneumoniae, and in 16 of 20 UTI caused by other bacterial species. Thus, 173 of 187 (92.5%) isolates responded to ampicillin therapy in a manner predicted by in vitro susceptibility test results. In vitro susceptibility testing correctly predicted the outcome of therapy with trimethoprim-sulfa in 119 of 138 UTI caused by Escherichia coli, in 33 of 45 UTI caused by Klebsiella pneumoniae, in 38 of 43 UTI caused by Proteus mirabilis, in 21 of 25 UTI caused by Streptococcus spp, in 9 of 11 UTI caused by coagulase-positive staphylococci, and in 19 of 21 UTI caused by other bacterial species. Thus, 239 of 283 (84%) isolates responded to trimethoprim-sulfa therapy in a manner predicted by in vitro susceptibility test results.  相似文献   

Characteristics of Salmonella isolated from animals at a veterinary medical teaching hospital   总被引：3，自引：0，他引：3  

J S Ikeda  D C Hirsh  S S Jang  E L Biberstein 《American journal of veterinary research》1986,47(2):232-235

Salmonella belonging to 47 serotypes was isolated from animals at the University of California Veterinary Medical Teaching Hospital during the years 1974 to 1983. Salmonella belonging to 12 serotypes accounted for 89% of the 725 isolates. Salmonella typhimurium (including var copenhagen) was the most commonly isolated serotype, but during 1981 to 1983, S krefeld and S saint-paul were predominant. Certain serotypes seemed to be isolated more frequently from extraintestinal sources (S typhi-suis, S dublin). Although resistance to ampicillin, kanamycin, neomycin, streptomycin, and sulfonamides was common (greater than 60% of the isolates were resistant), resistance to chloramphenicol, gentamicin, and trimethoprim-sulfonamides was infrequent, except for isolates of S krefeld and S saint-paul.  相似文献   

Transplacental infection of porcine fetuses following experimental challenge inoculation with encephalomyocarditis virus.   总被引：2，自引：0，他引：2  

W T Christianson  H S Kim  I J Yoon  H S Joo 《American journal of veterinary research》1992,53(1):44-47

Ten multiparous sows were inoculated between 46 and 50 days of gestation with a fetal swine isolate of encephalomyocarditis virus (EMCV) to investigate the ability of the virus to cause transplacental infection and fetal death. Four sows (group 1) were inoculated IM with EMCV MN-25 that had been passaged 4 times on baby hamster kidney-21 line cell monolayers. Two sows were euthanatized at postinoculation (PI) day 23, and the other 2 sows at PI day 44. An additional 6 sows (group 2) were inoculated IM with the same virus that had been passaged 5 additional times in pigs. Two sows were euthanatized at 14 days, and the remaining 4 sows at PI day 28. Clinical signs were not observed in any of the sows, whereas all sows seroconverted to EMCV. In group 1, only 2 of 50 fetuses were mummified. Virus was not recovered, although EMCV antibodies were detected in the 2 mummified fetuses. In group 2, the 2 sows that were euthanatized at PI day 14 had 26 normal fetuses and there was no evidence of fetal infection. However, in the 4 sows euthanatized at PI day 28, 20 of 48 fetuses were mummified, hemorrhagic, or edematous. Encephalomyocarditis virus was recovered from 21 of 48 fetuses. Transplacental infection and fetal deaths in pregnant sows was achieved following infection with EMCV passaged in pigs.  相似文献   

Multiplex polymerase chain reaction for distinguishing Taylorella equigenitalis from Taylorella equigenitalis-like organisms.     

A B Arata  C L Cooke  S S Jang  D C Hirsh 《Journal of veterinary diagnostic investigation》2001,13(3):263-264

It is difficult to distinguish isolates of Taylorella equigenitalis, the cause of contagious equine metritis, from a T. equigenitalis-like organism isolated from asymptomatic donkeys and horses. Although T. equigenitalis is responsible for a severe, contagious disease of the reproductive tract of equids, the T. equigenitalis-like organism, although contagious, does not appear to produce disease. Because of the economic consequences of correctly distinguishing isolates of these 2 microorganisms, a polymerase chain reaction (PCR)-based assay was developed that will distinguish isolates of T. equigenitalis from the T. equigenitalis-like microorganism. The primers used in the PCR assay were designed to amplify unique regions of the gene encoding the 16S ribosomal RNA.  相似文献   

Focal necrotizing pneumonia in cats associated with a gram negative eugonic fermenting bacterium   总被引：2，自引：0，他引：2  

S S Jang  J C Demartini  R V Henrickson  F M Enright 《The Cornell veterinarian》1973,63(3):446-454

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