Deterioration of the cell wall in waterlogged wooden archeological artifacts, 2400 years old

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 820-844 ◽  
Author(s):  
Juan Guo ◽  
Lin Xiao ◽  
Liuyang Han ◽  
Hao Wu ◽  
Tao Yang ◽  
...  
Keyword(s):  
Cell Wall ◽  
Free Water ◽  
Crystalline Cellulose ◽  
Ftir Microscopy ◽  
Ms Imaging ◽  
State Of Water ◽  
Spongy Texture ◽  
Gab Model ◽  
Archeological Artifacts ◽  
The Relationship

ABSTRACT The relationship between the cell wall ultrastructure of waterlogged wooden archeological artifacts and the state of water bound to cell walls and free in voids is fundamental to develop consolidating and drying technologies. Herein, a lacquer-wooden ware and a boat-coffin dating 4th century BC were selected as representative artifacts to study. Wood anatomy results indicated that they belonged to Idesia sp. and Machilus sp., respectively. They exhibited a typical spongy texture, as revealed by SEM observations, and their water contents had increased significantly. Solid state NMR, Py-GC/MS, imaging FTIR microscopy and 2D-XRD results demonstrated that the deterioration resulted from the partial cleavages of both polysaccharide backbones and cellulose hydrogen-bonding networks, almost complete elimination of acetyl side chains of hemicellulose, the partial depletion of β-O-4 interlinks, as well as oxidation and demethylation/demethoxylation of lignin. These further caused the disoriented arrangement of crystalline cellulose, and the decrease in cellulose crystallite dimensions and crystallinity. In consequence, mesopores and macropores formed, and the number of moisture-adsorbed sites and their accessibility increased. Moreover, results on free water deduced by the changes of pore structure and the maximum monolayer water capacity achieved by the GAB model indicated that water in waterlogged archeological wooden artifacts was mainly free water in mesopores.

scholarly journals Supercharged Cellulases Show Reduced Non-Productive Binding, But Enhanced Activity, on Pretreated Lignocellulosic Biomass

2021 ◽  
Author(s):  
Bhargava Nemmaru ◽  
Jenna Douglass ◽  
John M Yarbrough ◽  
Antonio De Chellis ◽  
Srivatsan Shankar ◽  
...  
Keyword(s):  
Cell Wall ◽  
Corn Stover ◽  
Lignocellulosic Biomass ◽  
Hydrolytic Activity ◽  
Fine Tuning ◽  
Cellulolytic Enzymes ◽  
Crystalline Cellulose ◽  
Cell Wall Components ◽  
Carbohydrate Binding Modules ◽  
Wall Components

Non-productive adsorption of cellulolytic enzymes to various plant cell wall components, such as lignin and cellulose, necessitates high enzyme loadings to achieve efficient conversion of pretreated lignocellulosic biomass to fermentable sugars. Carbohydrate-binding modules (CBMs), appended to various catalytic domains (CDs), promote lignocellulose deconstruction by increasing targeted substrate-bound CD concentration but often at the cost of increased non-productive enzyme binding. Here, we demonstrate how a computational protein design strategy can be applied to a model endocellulase enzyme (Cel5A) from Thermobifida fusca to allow fine-tuning its CBM surface charge, which led to increased hydrolytic activity towards pretreated lignocellulosic biomass (e.g., corn stover) by up to ~330% versus the wild-type Cel5A control. We established that the mechanistic basis for this improvement arises from reduced non-productive binding of supercharged Cel5A mutants to cell wall components such as crystalline cellulose (up to 1.7-fold) and lignin (up to 1.8-fold). Interestingly, supercharged Cel5A mutants that showed improved activity on various forms of pretreated corn stover showed increased reversible binding to lignin (up to 2.2-fold) while showing no change in overall thermal stability remarkably. In general, negative supercharging led to increase hydrolytic activity towards both pretreated lignocellulosic biomass and crystalline cellulose whereas positive supercharging led to a reduction of hydrolytic activity. Overall, selective supercharging of protein surfaces was shown to be an effective strategy for improving hydrolytic performance of cellulolytic enzymes for saccharification of real-world pretreated lignocellulosic biomass substrates. Future work should address the implications of supercharging cellulases from various families on inter-enzyme interactions and synergism.

Dikes on permafrost foundations in northern Manitoba

1970 ◽  
Vol 7 (4) ◽  
pp. 356-364 ◽  
Author(s):  
J. G. Macpherson ◽  
G. H. Watson ◽  
A. Koropatnick
Keyword(s):  
Electric Power ◽  
Heat Loss ◽  
Free Water ◽  
Northern Canada ◽  
Discontinuous Permafrost ◽  
Ice Content ◽  
The Relationship ◽  
Design And Construction

The development of hydro-electric power within the areas of low relief of northern Canada often requires long dikes to impound a reservoir. Much of this region lies within a zone of discontinuous permafrost, and dike design must allow for foundations varying from soft alluvial materials which will settle during or shortly after construction, to frozen strata with a high ice content which will settle as the ice thaws due to heat loss from the reservoir.This paper describes the approach to design and construction of dikes for the Kettle Generating Station in northern Manitoba, and includes a description of the instrumentation installed in an attempt to correlate the relationship between the rate of thawing of the permafrost and the rate of drainage of free water from the foundation.

scholarly journals Occurrence of cross-resistance and β-lactam seesaw effect in glycopeptide-, lipopeptide- and lipoglycopeptide-resistant MRSA correlates with membrane phosphatidylglycerol levels

2020 ◽  
Vol 75 (5) ◽  
pp. 1182-1186 ◽  
Author(s):  
Kelly M Hines ◽  
Tianwei Shen ◽  
Nathaniel K Ashford ◽  
Adam Waalkes ◽  
Kelsi Penewit ◽  
...  
Keyword(s):  
Cell Wall ◽  
Susceptibility Testing ◽  
Membrane Lipid ◽  
Cross Resistance ◽  
Membrane Composition ◽  
Membrane Lipid Composition ◽  
Usa300 Strain ◽  
Associated Proteins ◽  
The Relationship

Abstract Background Glycopeptides (GPs), lipopeptides (LPs) and lipoglycopeptides (LGPs) are related antimicrobials important for the management of invasive MRSA infections. Cross-resistance among these antibiotics in MRSA is well documented, as is the observation that susceptibility of MRSA to β-lactams increases as susceptibility to GPs and LPs decreases (i.e. the seesaw effect). Efforts to understand the relationship between GP/LP/LGP cross-resistance and the seesaw effect have focused on the PBPs, but the role of lipid metabolism has not been investigated. Objectives Since the cell membrane is structurally and metabolically integrated with the cell wall and anchors associated proteins, including PBPs, we examined the relationship between membrane lipid composition and the phenomena of cross-resistance among GPs/LPs/LGPs and the β-lactam seesaw effect. Methods We selected for daptomycin, vancomycin and dalbavancin resistance using the USA300 strain JE2 and evaluated the resulting mutants by WGS, MS-based lipidomics and antimicrobial susceptibility testing to assess the relationship between membrane composition, cross-resistance, and the seesaw effect. Results We observed cross-resistance to GPs/LPs/LGPs among the selected strains and the seesaw effect against various β-lactams, depending on the PBP targets of the particular β-lactam. We found that modification of membrane composition occurs not only in daptomycin-selected strains, but also vancomycin- and dalbavancin-selected strains. Significantly, we observed that the abundance of most phosphatidylglycerols positively correlates with MICs of GPs/LPs/LGPs and negatively correlates with the MICs of β-lactams. Conclusions These studies demonstrate a major association between membrane remodelling, cross-resistance and the seesaw effect.

scholarly journals Cellulose synthase interactive1- and microtubule-dependent cell wall architecture is required for acid growth in Arabidopsis hypocotyls

2020 ◽  
Vol 71 (10) ◽  
pp. 2982-2994 ◽  
Author(s):  
Xiaoran Xin ◽  
Lei Lei ◽  
Yunzhen Zheng ◽  
Tian Zhang ◽  
Sai Venkatesh Pingali ◽  
...  
Keyword(s):  
Cell Wall ◽  
Cell Elongation ◽  
Plant Cell Wall ◽  
Cellulose Microfibrils ◽  
Crystalline Cellulose ◽  
Cellulose Content ◽  
Acid Growth ◽  
Cell Wall Assembly ◽  
Dependent Cell ◽  
Cell Wall Architecture

Abstract Auxin-induced cell elongation relies in part on the acidification of the cell wall, a process known as acid growth that presumably triggers expansin-mediated wall loosening via altered interactions between cellulose microfibrils. Cellulose microfibrils are a major determinant for anisotropic growth and they provide the scaffold for cell wall assembly. Little is known about how acid growth depends on cell wall architecture. To explore the relationship between acid growth-mediated cell elongation and plant cell wall architecture, two mutants (jia1-1 and csi1-3) that are defective in cellulose biosynthesis and cellulose microfibril organization were analyzed. The study revealed that cell elongation is dependent on CSI1-mediated cell wall architecture but not on the overall crystalline cellulose content. We observed a correlation between loss of crossed-polylamellate walls and loss of auxin- and fusicoccin-induced cell growth in csi1-3. Furthermore, induced loss of crossed-polylamellate walls via disruption of cortical microtubules mimics the effect of csi1 in acid growth. We hypothesize that CSI1- and microtubule-dependent crossed-polylamellate walls are required for acid growth in Arabidopsis hypocotyls.

scholarly journals HOMOGENEOUS RABBIT 7S ANTI-IGG WITH ANTIBODY SPECIFICITY FOR PEPTIDOGLYCAN

1973 ◽  
Vol 138 (5) ◽  
pp. 1184-1193 ◽  
Author(s):  
Viktor A. Bokisch ◽  
Jen Wei Chiao ◽  
David Bernstein ◽  
Richard M. Krause
Keyword(s):  
Cell Wall ◽  
Antigenic Determinant ◽  
Antibody Specificity ◽  
Streptococcal Cell Wall ◽  
Cell Wall Peptidoglycan ◽  
Precipitin Reaction ◽  
Antigen Antibody ◽  
The Relationship

The relationship between 7S anti-IgG and antibodies to streptococcal cell wall peptidoglycan was examined for four streptococcal Group C antisera. Homogeneous 7S anti-IgG components in these sera were isolated by means of an IgG immunoadsorbent column. For two of the four antisera, the anti-peptidoglycan activity of the 7S anti-IgG had specificity for the pentapeptide, L-Ala-D-Glu-γ-L-Lys-D-Ala-D-Ala, the antigenic determinant of peptidoglycan, as well as for the Fc of IgG. Detailed studies on the 7S anti-IgG from one of the antisera revealed that the pentapeptide inhibited the coprecipitation reaction of 7S anti-IgG R3387 with antigen-antibody complexes and the precipitin reaction between 7S anti-IgG R3387 and its anti-idiotype serum.

New Insights into the Physiology of Peritoneal Fluid Transport

2008 ◽  
Vol 28 (3_suppl) ◽  
pp. 144-149
Author(s):  
Raymond T. Krediet ◽  
Annemieke M. Coester ◽  
Alena Parikova ◽  
Watske Smit ◽  
Dirk G. Struijk
Keyword(s):  
Water Transport ◽  
Fluid Transport ◽  
Free Water ◽  
Osmotic Gradient ◽  
Ultrafiltration Failure ◽  
Ultra Filtration ◽  
Relationship Of ◽  
The Relationship

A review is given on the mechanisms of free water transport, the various methodologies for its measurement, its dependency on the osmotic gradient, and the assessment of osmotic conductance in individual patients. The importance of impaired free water transport in long-term ultra-filtration failure is discussed, relative to peritoneal solute transport status. Furthermore, the relationship of free water transport with locally released potassium is considered, together with a potential role of impaired K+ channel function with peritoneal alterations. Finally, the role of impaired osmotic conductance to glucose and its effects on free water transport in long-term patients with ultrafiltration failure is reviewed.

Relationship of wood cell wall ultrastructure to bacterial degradation of wood

IAWA Journal ◽  
2019 ◽  
Vol 40 (4) ◽  
pp. 845-870 ◽  
Author(s):  
Adya P. Singh ◽  
Yoon Soo Kim ◽  
Ramesh R. Chavan
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Wood Cell Wall ◽  
Bacterial Degradation ◽  
Cell Wall Components ◽  
Degrading Bacteria ◽  
Wall Ultrastructure ◽  
Relationship Of ◽  
The Relationship ◽  
Wall Components

ABSTRACT This review presents information on the relationship of ultrastructure and composition of wood cell walls, in order to understand how wood degrading bacteria utilise cell wall components for their nutrition. A brief outline of the structure and composition of plant cell walls and the degradation patterns associated with bacterial degradation of wood cell walls precedes the description of the relationship of cell wall micro- and ultrastructure to bacterial degradation of the cell wall. The main topics covered are cell wall structure and composition, patterns of cell wall degradation by erosion and tunnelling bacteria, and the relationship of cell wall ultrastructure and composition to wood degradation by erosion and tunnelling bacteria. Finally, pertinent information from select recent studies employing molecular approaches to identify bacteria which can degrade lignin and other wood cell wall components is presented, and prospects for future investigations on wood degrading bacteria are explored.

Seasonally varying relationship between stem respiration, increment and carbon allocation of Norway spruce trees

2020 ◽  
Vol 40 (7) ◽  
pp. 943-955
Author(s):  
Eva Darenova ◽  
Petr Horáček ◽  
Jan Krejza ◽  
Radek Pokorný ◽  
Marian Pavelka
Keyword(s):  
Cell Wall ◽  
Norway Spruce ◽  
Carbon Allocation ◽  
Stem Growth ◽  
Wall Thickening ◽  
Radial Increment ◽  
Stem Respiration ◽  
Energy Demands ◽  
The Relationship ◽  
Stem Radial Increment

Abstract Stem respiration is an important component of an ecosystem’s carbon budget. Beside environmental factors, it depends highly on tree energy demands for stem growth. Determination of the relationship between stem growth and stem respiration would help to reveal the response of stem respiration to changing climate, which is expected to substantially affect tree growth. Common measurement of stem radial increment does not record all aspects of stem growth processes, especially those connected with cell wall thickening; therefore, the relationship between stem respiration and stem radial increment may vary depending on the wood cell growth differentiation phase. This study presents results from measurements of stem respiration and increment carried out for seven growing seasons in a young Norway spruce forest. Moreover, rates of carbon allocation to stems were modeled for these years. Stem respiration was divided into maintenance (Rm) and growth respiration (Rg) based upon the mature tissue method. There was a close relationship between Rg and daily stem radial increment (dSRI), and this relationship differed before and after dSRI seasonal maximum, which was around 19 June. Before this date, Rg increased exponentially with dSRI, while after this date logarithmically. This is a result of later maxima of Rg and its slower decrease when compared with dSRI, which is connected with energy demands for cell wall thickening. Rg reached a maxima at the end of June or in July. The maximum of carbon allocation to stem peaked in late summer, when Rg mostly tended to decrease. The overall contribution of Rg to stem CO2 efflux amounted to 46.9% for the growing period from May to September and 38.2% for the year as a whole. This study shows that further deeper analysis of in situ stem growth and stem respiration dynamics is greatly needed, especially with a focus on wood formation on a cell level.

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