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1.
Cloning in Streptococcus lactis of plasmid-mediated UV resistance and effect on prophage stability. 总被引:5,自引:4,他引:1 下载免费PDF全文
Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains. 相似文献
2.
L Hartmann A F Bringuier N Chopin C Kechrid D Fries 《Comptes rendus des séances de la Société de biologie et de ses filiales》1985,179(4):452-461
The study of 24-h urinary excretion proves to be quite interesting from a theoretical point of view on account of its topographic origin in the nephron and from a practical point of view to control renal transplant patients with favourable or unfavourable course. In both cases, the results we obtain are in accordance with that of blood creatinine assay and ratio N-acetyl-beta-D-glucosaminidase (NAG)/creatinine in urine. The prolonged study of serum THG concentration confirms the previous data regarding the outcome of renal grafts. Moreover, particularly low concentration rates probably imply the interference of factors such as: renal toxins or anti-THG autoantibodies. 相似文献
3.
Abstract By using an extension to group N streptococci of a contransformation procedure we have introduced 4 different-sized cryptic plasmids for Streptococcus lactis into the plasmid-free S. lactis IL1403. A mixture of 4 cryptic plasmids with an indicator plasmid (pHV1301) conferring erythromycin resistance was used for IL1403 protoplast transformation. Under such conditions, 41.5% of the erythromycin-resistant transformants were contransformed with one of the cryptic plasmids in addition to pHV1301. Indicator plasmid pHV1301 was later spontaneously segregated from doubly transformed cells. This protocol should be very useful for constructing lactic streptococcal strains bearing any phenotypically cryptic plasmid. 相似文献
4.
Plasmid pIL7 (33 kilobases) from Streptococcus lactis enhances UV resistance and prophage stability. A 5.4-kilobase pIL7 fragment carrying genes coding for both characters was cloned into S. lactis, using plasmid pHV1301 as the cloning vector. The recombinant plasmid was subsequently transferred to three other S. lactis strains by transformation or protoplast fusion. Cloned genes were expressed in all tested strains. 相似文献
5.
C-Glycosylation of 5,7-dihydroxy-3′,4′,5′-trimethoxyflavone was carried out with acetobromo-α-d-glucose, -α-d-galactose, -α-d-xylose, -β-l-arabinose and -αt-L-rhamnose. The respective 6-C-glycosides and 6, 8-di-C-glycosides (excepted for galactose) were isolated and permethylated. MS and TLC comparison confirmed the proposed structures of five natural tricetin-derived C-glycosides. 相似文献
6.
Two isovitexin 2″-O-glycosides have been isolated from primary leaves of rye and identified as isovitexin 2″-O-arabinoside and isovitexin 2 相似文献
7.
6-C-α-l-Arabinopyranosyl- and furanosylacacetins have been synthesized. They are isomerized by short acid treatment to give a mixture of the four anomer/ring size combinations without any Wessely-Moser isomerization. In the same conditions molludistin (8-C-α-l-arabinopyranosylgenkwanin) led only to a mixture of molludistin and 8-C-α-l-arabinofuranosylgenkwanin. This is the first demonstration of ring sugar isomerization in C-glycosylflavones. In usual solvent systems, α-anomers are easily separated from β-anomers, whereas corresponding pyranosyl and furanosyl anomers are not. However, they are easily separated after permethylation and characteristic features are found in the mass spectra of PM 6-C-arabinofuranosyl isomers. 相似文献
8.
Five C-glycosylflavonoids including two new compounds, isovitexin 7-rhamnosylglucoside and isomollupentin 7-rhamnosylglucoside, were obtained from the leaves of Passiflora platyloba. The known flavonoids were isovitexin, vitexin and isomollupentin (6-C-arabinosylapigenin). In addition, the coumarin esculetin was isolated. 相似文献
9.
C-Glycosylflavones have been identified in Ephedra antisyphilitica, Gnetum gnemon and Welwitschia mirabilis. The C-glycosidic moieties of apigenin and luteolin derivatives have been identified as glucose and/or xylose for these species. 相似文献
10.