| Value |
7.8
nm
|
| Organism |
Bacteria Escherichia coli |
| Reference |
Hobot JA, Carlemalm E, Villiger W, Kellenberger E. Periplasmic gel: new concept resulting from the reinvestigation of bacterial cell envelope ultrastructure by new methods. J Bacteriol. 1984 Oct160(1):143-52. Table - link PubMed ID6207168
|
| Method |
Value is average of six values given in second column from left of table link. E. coli B was maintained on nutrient
agar slants (1.5% [wt/vol] nutrient broth [Difco Laboratories,
Detroit, Mich.], 0.5% [wt/vol] NaCl, 2% [wt/vol] agar
[Difco]) grown overnight in liquid culture (1% [wt/vol]
tryptone [Difco], 0.5% [wt/vol] NaCl) at 37°C plus aeration
and subcultured the following day into fresh liquid culture
until exponentially growing cells were observed (ca. 1.5 h 2
x 10^8 cells/ml). Isolation of peptidoglycan and density determinations. Cell envelope preparation. Electron microscopy. |
| Comments |
Researchers felt that the new progressive lowering of
temperature (PLT) embedding procedure for electron microscopy might counter some of the adverse influences
of dehydration in a manner that would provide new
and additional data concerning cell envelope ultrastructure
(J. A. Hobot, E. Carlemalm, and E. Kellenberger, Experientia
37:1226, 1981). When E. coli is fixed with osmium and
embedded in Epon, the envelope shows several layers: the
double track of an outer membrane with an underlying
intermediate layer (the G layer described by DePetris).
This intermediate layer was assumed to be composed of a
compact peptidoglycan layer (layer g2 described by DePetris) separated from the outer membrane by a globular
protein layer (layer g1 described by DePetris). This
interpretation confirmed the observations of Murray et al.
for the location and thickness (2.0 to 3.0 nm) of the
peptidoglycan layer, which is in agreement with the calculated
thickness of a peptidoglycan monolayer in the E. coli
envelope and the model for a compact, crystalline layer
of peptidoglycan based on X-ray data. See BNID 105385 for peptidoglycan width of 6.35±0.53 nm in the periplasm of Escherichia coli. For width of 5nm see Kern et al., 2010 PMID 20681725 p.10916 right column top paragraph |
| Entered by |
Uri M |
| ID |
105383 |