Comparison of the cell envelope structure of a lipopolysaccharide-defective (heptose-deficient) strain and a smooth strain of Salmonella typhimurium.
AUTOR(ES)
Irvin, R T
RESUMO
The cell envelope structure of Salmonella typhimurium LT2, which has a heptose-deficient lipopolysaccharide (LPS), is significantly different from that of an isogenic strain with a normal LPS. The rough strain, when examined by freeze-etching, lacks most surface structures that are routinely present in the smooth strain (surface particles and flagella) and has few transmemberane studs in the cytoplasmic membrane (those present are generally found in aggregates), and the outer membrane cleavage is substantially stronger than that of the smooth strain. These envelope differences were independent of both growth temperature and culture age. Examination of ultrathin sections indicated that the rough strain has an outer membrane which forms a much more defined double-track artifact than the smooth strain. The addition of MgCl2 to the growth medium of the rough strain decreased the extent of outer membrane cleavage, and flagella became evident in freeze-etched preparations. The presence of supplemental MgCl2 in the growth medium, which resulted in these morphological changes in the rough strain, also produced growth at a previously restrictive temperature and a decrease in the leakage of periplasmic enzymes. The smooth strain was unaltered morphologically or physiologically by MgCl2 under identical conditions. It is suggested that the outer membrane of the rough strain is more planar.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=235984Documentos Relacionados
- Colonization of the mouse intestine by an avirulent Salmonella typhimurium strain and its lipopolysaccharide-defective mutants.
- Lipopolysaccharide-Defective Mutants of the Wilt Pathogen Pseudomonas solanacearum
- Susceptibility of lipopolysaccharide-defective mutants of Pseudomonas aeruginosa strain PAO to dyes, detergents, and antibiotics.
- Citrate-Tris(hydroxymethyl)aminomethane-Mediated Release of Outer Membrane Sections from the Cell Envelope of a Deep-Rough (Heptose-Deficient Lipopolysaccharide) Strain of Escherichia coli O8
- Citrate-tris(hydroxymethyl)aminomethane-mediated release of outer membrane sections from the cell envelope of a deep-rough (heptose-deficient lipopolysaccharide) strain of Escherichia coli O8.