The Chemical Composition and Serological Reactions of Lipopolysaccharides from Serogroups A, B, X, and Y Neisseria meningitidis

1973 ◽  
Vol 51 (10) ◽  
pp. 1347-1354 ◽  
Author(s):  
H. J. Jennings ◽  
G. B. Hawes ◽  
G. A. Adams ◽  
C. P. Kenny
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Sialic Acid ◽  
Chemical Composition ◽  
Neisseria Meningitidis ◽  
Main Part ◽  
Lipid A ◽  
The Core ◽  
Serological Studies ◽  
The Individual

Analyses of the cell wall lipopolysaccharides prepared from Neisseria meningitidis serogroups A, B, X, and Y, indicated that they all contained glucose, galactose, glucosamine, heptose, lipid A, ethanolamine, fatty acids, phosphate, and protein. Some minor compositional differences in the sugar components did occur in that sialic acid (6–7%) was found only in serogroups B and Y, and galactosamine (2–3%) in serogroups B and X. The individual fatty acid and amino acid components in the four serogroups were also qualitatively similar. The Neisseria lipopolysaccharides studied have the same components as the core structure of the Enterobacterioceae but appear to lack the characteristic components of their O-antigen side chains. Serological studies indicated that the lipopolysaccharides were homogeneous and were for the main part group specific in nature, despite their compositional similarity. On the basis of compositional differences alone it is not possible to account for the group specificity that they exhibit.

The effect of growth environment on the chloroform–methanol and alkali-extractable cell wall and cytoplasm lipid levels of Mucor rouxii

1975 ◽  
Vol 21 (1) ◽  
pp. 79-84 ◽  
Author(s):  
S. Safe ◽  
J. Caldwell
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Cell Walls ◽  
Lipid Levels ◽  
Mucor Rouxii ◽  
Growth Environment ◽  
Lipid Fractions ◽  
Filamentous Cell ◽  
The Individual ◽  
Chloroform Methanol

The distribution of chloroform–methanol and alkali-extractable lipids in the cell walls of aerobically grown filamentous cells from Mucor rouxii has been determined. The results have been compared with the corresponding lipid composition of yeast-like cells from M. rouxii, which can be produced in two ways: by growth under anaerobic conditions and by aerobic growth in the presence of 0.22% phenethyl alcohol (PEA). It was observed that in most cases the crude cytoplasmic fraction contained higher levels of several lipids (i.e., squalene, sterols, triterpenes, and fatty acids) than did the corresponding cell walls. The cell walls did, however, contain both "free" (chloroform–methanol extractable) and "bound" (alkali extractable) lipids although the relative amounts were markedly dependent on the cell growth environment. The aerobically grown filamentous cell walls contained higher levels of squalene, sterols, triterpenes, and fatty acids than did aerobically grown yeast-like PEA-induced cell walls and there was also considerable variation in the "free''/"bound" ratios of the various lipid components. The lipid levels in both the cell walls and cytoplasm of the anaerobically grown cells were considerably lower than those of the cells grown under aerobic conditions. In addition, the differences in the growth environment were also reflected in the compositions of the individual lipid fractions from both the cell wall and the cytoplasm fraction.

scholarly journals Infrared photo-induced force microscopy unveils nanoscale features of Norway spruce fibre wall

Cellulose ◽  
2021 ◽  
Author(s):  
Kavindra Kumar Kesari ◽  
Padraic O’Reilly ◽  
Jani Seitsonen ◽  
Janne Ruokolainen ◽  
Tapani Vuorinen
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Norway Spruce ◽  
Spatial Resolution ◽  
Lignin Content ◽  
Force Microscopy ◽  
Transmission Electron ◽  
High Resolution Images ◽  
The Individual ◽  
20 Nm

AbstractInfrared photo-induced force microscopy (IR PiFM) was applied for imaging ultrathin sections of Norway spruce (Picea abies) at 800–1885 cm−1 with varying scanning steps from 0.6 to 30 nm. Cell wall sublayers were visualized in the low-resolution mode based on differences in their chemical composition. The spectra from the individual sublayers demonstrated differences in the orientation of cellulose elementary fibrils (EFs) and in the content and structure of lignin. The high-resolution images revealed 5–20 nm wide lignin-free areas in the S1 layer. Full spectra collected from a non-lignified spot and at a short distance apart from it verified an abrupt change in the lignin content and the presence of tangentially oriented EFs. Line scans across the lignin-free areas corresponded to a spatial resolution of ≤ 5 nm. The ability of IR PiFM to resolve structures based on their chemical composition differentiates it from transmission electron microscopy that can reach a similar spatial resolution in imaging ultrathin wood sections. In comparison with Raman imaging, IR PiFM can acquire chemical images with ≥ 50 times higher spatial resolution. IR PiFM is also a surface-sensitive technique that is important for reaching the high spatial resolution in anisotropic samples like the cell wall. All these features make IR PiFM a highly promising technique for analyzing the recalcitrant nature of lignocellulosic biomass for its conversion into various materials and chemicals. Graphic abstract

scholarly journals Decomposition of Microbial Necromass Is Divergent at the Individual Taxonomic Level in Soil

2021 ◽  
Vol 12 ◽  
Author(s):  
Weiling Dong ◽  
Alin Song ◽  
Huaqun Yin ◽  
Xueduan Liu ◽  
Jianwei Li ◽  
...  
Keyword(s):  
Cell Wall ◽  
Chemical Composition ◽  
Microbial Biomass ◽  
Operational Taxonomic Unit ◽  
Stable Isotope Probing ◽  
Soil Organic C ◽  
Organic C ◽  
Operational Taxonomic Units ◽  
Taxonomic Level ◽  
The Individual

The turnover of microbial biomass plays an important part in providing a significant source of carbon (C) to soil organic C. However, whether the decomposition of microbial necromass (non-living microbial biomass) in the soil varies at the individual taxa level remains largely unknown. To fill up these gaps, we compared the necromass decomposition of bacterial and archaeal taxa by separating live microbial biomass with 18O-stable isotope probing from dead microbial biomass in soil. Our results showed that most of the microbial necromass at the operational taxonomic unit level (88.51%), which mainly belong to Acidobacteria, Actinobacteria, Gemmatimonadetes, and Proteobacteria, decomposed significantly after 30 days. In addition, there were great variations in necromass decomposition within each phylum, such as the decomposition of operational taxonomic units in Proteobacteria that ranged from 51% (Beijerinckia) to 92% (Nitrosospira). More importantly, the necromass decomposition was not related to the chemical composition of the cell wall but might positively correlate with the guanine–cytosine content of DNA and negatively correlated with genome size. This study provided a new insight that the decomposition of microbial necromass in soil was divergent at the individual taxonomic level and could not be fully explained by previously proposed mechanisms.

The chemical composition of cell-wall lipopolysaccharides from Moraxella duplex and Micrococcus calco-aceticus

1970 ◽  
Vol 16 (1) ◽  
pp. 1-8 ◽  
Author(s):  
G. A. Adams ◽  
C. Quadling ◽  
M. Yaguchi ◽  
T. G. Tornabene
Keyword(s):  
Fatty Acids ◽  
Cell Wall ◽  
Lipid A ◽  
Amino Sugar ◽  
Neutral Sugar ◽  
Sugar Composition ◽  
Cyclopropane Fatty Acids ◽  
Novel Structure ◽  
Backbone Structure ◽  
Fatty Acid Compositions

Cell wall lipopolysaccharides (LPS) prepared from oxidase-positive Moraxella duplex and from oxidase-negative Micrococcus calco-aceticus (a presumptive moraxella) contained D-glucose, D-galactose, glucosamine, galactosamine, lipid A, ethanolamine, fatty acids, phosphate, and protein. The lipid A moieties prepared from the LPS fractions were composed primarily of hexosamines, ethanolamine, fatty acids, and phosphate with minor amounts of the other LPS constituents. The LPS from M. duplex and M. calco-aceticus had the same neutral sugar composition but differed markedly in their hexosamine composition. Galactosamine was the major hexosamine component of M. duplex; also present was an unidentified amino sugar and a small amount of mannosamine. In contrast, glucosamine was the major hexosamine component of M. calco-aceticus with a lesser amount of galactosamine and no mannosamine. The presence of galactosamine as the major component of the lipid A of M. duplex suggests that this fraction has a novel structure which differs from the poly-D-glucosamine 'backbone' structure assigned to lipid A. The fatty acid compositions of the lipid A from the two species were mutually similar and consisted mainly of hydroxylauric, hydroxymyristic, and C17-cyclopropane fatty acids. The LPS fractions of the two organisms studied resemble that of Neisseria catarrhalis and differ from those of the true neisserias.

A lipopolysaccharide-specific bacteriophage for Aeromonas salmonicida

1983 ◽  
Vol 29 (10) ◽  
pp. 1458-1461 ◽  
Author(s):  
E. E. Ishiguro ◽  
Teresa Ainsworth ◽  
D. H. Shaw ◽  
W. W. Kay ◽  
T. J. Trust
Keyword(s):  
Cell Wall ◽  
Lipid A ◽  
Aeromonas Salmonicida ◽  
Receptor Activity ◽  
Core Oligosaccharide ◽  
The Core ◽  
Phage Adsorption ◽  
Specific Bacteriophage

Cell wall lipopolysaccharide (LPS) was identified as the receptor for the Aeromonas salmonicida bacteriophage strain 55R-1. Mutants of A. salmonicida resistant to phage 55R-1 were unable to adsorb phage 55R-1 and were shown to be defective in LPS structure. Purified A. salmonicida LPS inactivated phage 55R-1, but the O-polysaccharide and the core oligosaccharide portions of the LPS were ineffective. These results suggest that lipid A was required for receptor activity. Antibodies directed against LPS also inhibited phage adsorption.

Reply to Connor and Evers (2020): Critique of the Bias of Crowds Model Simply Restates the Model

2020 ◽  
Author(s):  
Keith Payne ◽  
Heidi A. Vuletich ◽  
Kristjen B. Lundberg
Keyword(s):  
Implicit Bias ◽  
Group Level ◽  
Systemic Racism ◽  
Individual Level ◽  
The Core ◽  
Psychological Science ◽  
Implicit Biases ◽  
The Individual

The Bias of Crowds model (Payne, Vuletich, & Lundberg, 2017) argues that implicit bias varies across individuals and across contexts. It is unreliable and weakly associated with behavior at the individual level. But when aggregated to measure context-level effects, the scores become stable and predictive of group-level outcomes. We concluded that the statistical benefits of aggregation are so powerful that researchers should reconceptualize implicit bias as a feature of contexts, and ask new questions about how implicit biases relate to systemic racism. Connor and Evers (2020) critiqued the model, but their critique simply restates the core claims of the model. They agreed that implicit bias varies across individuals and across contexts; that it is unreliable and weakly associated with behavior at the individual level; and that aggregating scores to measure context-level effects makes them more stable and predictive of group-level outcomes. Connor and Evers concluded that implicit bias should be considered to really be noisily measured individual construct because the effects of aggregation are merely statistical. We respond to their specific arguments and then discuss what it means to really be a feature of persons versus situations, and multilevel measurement and theory in psychological science more broadly.

Pathways to Success Through Identity-Based Motivation

2015 ◽  
Author(s):  
Daphna Oyserman
Keyword(s):  
The Self ◽  
The Core ◽  
Very Young Children ◽  
The Future ◽  
Identity Based ◽  
Future Self ◽  
Fidelity Measures ◽  
The Individual ◽  
Taking Action ◽  
Minimal Effort

Everyone can imagine their future self, even very young children, and this future self is usually positive and education-linked. To make progress toward an aspired future or away from a feared future requires people to plan and take action. Unfortunately, most people often start too late and commit minimal effort to ineffective strategies that lead their attention elsewhere. As a result, their high hopes and earnest resolutions often fall short. In Pathways to Success Through Identity-Based Motivation Daphna Oyserman focuses on situational constraints and affordances that trigger or impede taking action. Focusing on when the future-self matters and how to reduce the shortfall between the self that one aspires to become and the outcomes that one actually attains, Oyserman introduces the reader to the core theoretical framework of identity-based motivation (IBM) theory. IBM theory is the prediction that people prefer to act in identity-congruent ways but that the identity-to-behavior link is opaque for a number of reasons (the future feels far away, difficulty of working on goals is misinterpreted, and strategies for attaining goals do not feel identity-congruent). Oyserman's book goes on to also include the stakes and how the importance of education comes into play as it improves the lives of the individual, their family, and their society. The framework of IBM theory and how to achieve it is broken down into three parts: how to translate identity-based motivation into a practical intervention, an outline of the intervention, and empirical evidence that it works. In addition, the book also includes an implementation manual and fidelity measures for educators utilizing this book to intervene for the improvement of academic outcomes.

scholarly journals Location of fatty acids in lipid A obtained from lipopolysaccharide of Rhodopseudomonas sphaeroides ATCC 17023.

1988 ◽  
Vol 263 (12) ◽  
pp. 5502-5504
Author(s):  
N Qureshi ◽  
J P Honovich ◽  
H Hara ◽  
R J Cotter ◽  
K Takayama
Keyword(s):  
Fatty Acids ◽  
Lipid A ◽  
Rhodopseudomonas Sphaeroides

scholarly journals Mare’s Milk from a Small Polish Specialized Farm—Basic Chemical Composition, Fatty Acid Profile, and Healthy Lipid Indices

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1590
Author(s):  
Grażyna Czyżak-Runowska ◽  
Jacek Antoni Wójtowski ◽  
Romualda Danków ◽  
Daniel Stanisławski
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Chemical Composition ◽  
Birth Order ◽  
Fatty Acid Profile ◽  
Age Structure ◽  
Atherogenic Index ◽  
Milk Samples ◽  
Stage Of Lactation ◽  
Bulk Tank

The objective of this study was to determine the chemical composition, fatty acid profile, and values of healthy indices of milk from a specialized farm of Polish Coldblood mares of different ages, birth orders, and lactation stages. Milk samples (n = 48) were collected for analysis in weeks 10, 15, and 25 of lactation from mares aged between five and 14 years. The study showed that the stage of lactation has a significant effect on the fatty acid (FA) profile of the milk produced on the farm. The highest concentration of monounsaturated and polyunsaturated FAs was found in milk produced from the 15th week of lactation. The milk was also characterized by low values of atherogenic and thrombogenic indices, which indicate the health benefits of milk with respect to the content of fatty acids and their potential to prevent or cause atherosclerosis and thrombosis. The study also found a significant correlation between the number of foalings (birth order), the fatty acid profile, and atherogenic index of milk produced on the farm. The findings from the study indicate that it is possible to modify the fatty acid profile of bulk tank milk through appropriate management of the age structure of the herd of mares. To confirm this dependence, the study will be continued on a larger group of mares.

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