Properties of R Factors Isolated from Multiple-ResistanceProteus rettgeri

Transduction of R factors in Proteus mirabilis and P. rettgeri.

Phage 34 transduces some R factors to Proteus mirabilis strain 13. These transductants can transmit the R factor by conjugation. Transduction frequencies vary from I x I ~-~/plaque-forming unit (p.f.u.) adsorbed (higher than .chromosomal marker transduction) to 5 x Io-8/p.f.u. adsorbed. Transduced drug resistance markers of other R factors were detected only in the presence of resident$factors ...

Properties of R factors from Bordetella bronchiseptica.

Genetic properties and host ranges of R factors derived from Bordetella bronchiseptica of pig origin were examined. All of 61 R factors tested could confer resistance to streptomycin, sulfonamide, and aminobenzyl penicillin on their host bacteria. All of them were identified as fi(-) (no fertility inhibition) type and were found to exhibit no restriction of phages lambda, phi80, P1, P2, T1, T3,...

acylase from Providencia rettgeri

Two isoforms of the heterodimeric enzyme penicillin G acylase (EC 3.5.1.1 I ) from Providencia rettgeri ATCC 31052 (strain Brol) were purified to near homogeneity. The isoforms exhibited comparable enzymatic a tivities but differed slightly in the molecular weight and PI of their respective a-subunit. The origin of this difference was traced to the partial conversion of the N-terminal Gln of th...

extraction and acetylation of purified trypsin from bovin pancreas and study of some its physico-chemical properties

آنزیم تریپسین در شرایط قلیایی ناپایدار می باشد .و فعالیت پروتئولیتیکی تریپسین منجربه خود هضمی آن در جایگاههای خاصی می گردد. بنابر این آنزیمی با ناپایداری بالا محسوب میگردد. در سالهای اخیر موفق شدند که با ایجاد تغیرات شیمیایی با اضافه کردن فلزات خاص ، کلسیم و یا عمل استیلاسیون منجر به افزایش پایداری آنزیم تریپسین گردند. مطالعات در حال حاضر نشان می دهد که تریپسین استیله شده فعالیت آنزیمی خود را ...

an Investigation of Factors Affecting Utilization of MOOC from the perspective of R MOOC learners