Isolation and characterization of plasmid from the Bacillus brevis var. G.-B. cells

Abstract

The plasmid designated pAD1 was isolated from the cells of four variants of Bacillus brevis var. G.-B. The plasmid DNA has a molecular weight of about 47.1 x 10(6) daltons and contains 43.4 mole % G+C. The bulk of pAD1 DNA (96--98%) is associated with the fraction of chromosome DNA and membranes. Restriction endonucleases Sma I, Sal I and Bam HI cleaved the plasmid DNA into two, two and six fragments, respectively. The cleavage map of the pAD1 genome has been constructed for these three endonucleases. Restriction enzymes Eco RI, Hind III, Kpn I and Pst I hydrolized the plasmid DNA into 16, 21, 10 and 9 fragments, respectively. The presence of repeated sequences in the plasmid genome was shown based on pAD1 DNA cleavage by these endonucleases.

Isolation and Partial Characterization of Three Cryptic Plasmids from Strains of Clostridium butyricum

“…It was conceivable that any large plasmid which may have been present in any of the strains of C. butyricum might have co-precipitated with the membrane and/or chrolnosomal DNA fractions in the course of the preparation of the cleared lysate (cf. Currier & Nester, 1976;Dobrista et al, 1978). Thus, as alternatives to the routine screening procedure (see Methods), two other preparatory methods were employed which should have ensured that any large plasmid would have been retained and included in the final DNA samples which were examined by agarose gel electrophoresis.…”

“…Thus, as alternatives to the routine screening procedure (see Methods), two other preparatory methods were employed which should have ensured that any large plasmid would have been retained and included in the final DNA samples which were examined by agarose gel electrophoresis. These methods exploited alkaline denaturation either (a) of the cell lysates, as described by Hansen & Olsen (1978) or (b) of the pellet obtained by centrifugation of the cell lysates following addition of SDS (final concentration 4%, w/v) and 1 M-NaCl (Dobrista et al, 1978). In both cases the final DNA preparations were concentrated either by precipitation with ethanol (as in Methods) or with polyethylene glycol (PEG 6000; Merck) as described by Humphreys et al (1975).…”

Plasmids of Salt-tolerant Rhizosphere Microorganisms

“…При диссоциации популяции Bacillus brevis была выявлена одна боль шая плазмида рАД1 60,0 т.п.н., которая, по мнению авторов, играла важ ную роль в диссоциации культуры. При элиминации этой плазмиды клет ки теряли способность к образованию эндоспор [8].…”

Large plasmids in an actinomycete

“…A crude lysate from R. leguminosarum T3 cells containing plasmid DNAs was obtained according to the procedure of Kado and Liu [20]. A plasmid complex from B. megaterium 216 was isolated as described previously [21,22].…”