Isolated cell walls of Staphylococcus aureus and Micrococcus lysodeikticus were found to expand and contract in response to changes in environmental pH and ionic strength. These volume changes, which could amount to as much as a doubling of wall dextran-impermeable volume, were related to changes in electrostatic interactions among fixed, ionized groups in wall polymers, including peptidoglycan...

Cell walls are of interest to plant biochemists and cell biologists for two main reasons: they regulate cellular morphogenesis and act as structural support materials. As it is a major component of plant cell walls and a natural product of considerable commercial value, cellulose has long been a focus of interest in cell-wall biology, although it is far from the only constituent of cell walls. ...

Extensins are members of the cell wall hydroxyproline-rich glycoprotein (HRGP) superfamily that form covalently cross-linked networks in primary cell walls. A knockout mutation in EXT3 (AT1G21310), the gene coding EXTENSIN 3 (EXT3) in Arabidopsis Landsberg erecta resulted in a lethal phenotype, although about 20% of the knockout plants have an apparently normal phenotype (ANP). In this study th...

Stimulation of [(3)H]thymidine incorporation of thymocytes and splenocytes from guinea pigs by various bacterial cell walls and their peptidoglycans, by enzymatic digests, and by synthetic muramyl dipeptides was studied as an indication of mitogenic activity. Cell wall and peptidoglycan preparations, isolated from 19 strains belonging to 18 different species, definitely increased [(3)H]thymidin...

Background Xylan is a major hemicellulosic component in the cell walls of higher plants especially in the secondary walls of vascular cells which are playing important roles in physiological processes and overall mechanical strength. Being the second most abundant cell wall polymer after cellulose, xylan is an abundant non-cellulosic carbohydrate constituent of plant biomass. Xylan structures h...

Cell walls from flesh, parenchyma cells, stone cells and skin were isolated from ripe and overripe Pyrus communis L. cv "De Cloche" using the phenol-buffer method. Pear polysaccharides were solubilized from cell walls by sequential extractions with aqueous solutions of ammonium oxalate, Na2CO3, and increasing concentration of NaOH, to explore overripening impact. Cell walls were also differenti...

T he surfaces of microbial cells are perhaps their most important structure because they are in immediate contact with the external environment. Microbial cell walls admit nutrients and release wastes, and yet they must resist internal turgor pressure and environmental insults and maintain cellular shape. Walls also help cells adhere to other surfaces and provide space for specialized structure...

Introduction Plant cell walls constitute the key structural components of plants and many foods derived thereof. For decades, it has also been appreciated that they play a central role in determining the quality characteristics of many plant-based foods, particularly texture (Van Buren 1979). There is an implicit assumption that by understanding the physics, chemistry, biochemistry, and molecul...