scholarly journals The Cell Membrane of Sulfolobus spp.—Homeoviscous Adaption and Biotechnological Applications

2020 ◽  
Vol 21 (11) ◽  
pp. 3935 ◽  
Author(s):  
Kerstin Rastädter ◽  
David J. Wurm ◽  
Oliver Spadiut ◽  
Julian Quehenberger
Keyword(s):  
Cell Membrane ◽  
Environmental Changes ◽  
Specific Growth ◽  
Membrane Lipids ◽  
Environmental Parameters ◽  
Coping Mechanism ◽  
Biotechnological Applications ◽  
Head Groups ◽  
Tetraether Lipids ◽  
Archaeal Lipids

The microbial cell membrane is affected by physicochemical parameters, such as temperature and pH, but also by the specific growth rate of the host organism. Homeoviscous adaption describes the process of maintaining membrane fluidity and permeability throughout these environmental changes. Archaea, and thereby, Sulfolobus spp. exhibit a unique lipid composition of ether lipids, which are altered in regard to the ratio of diether to tetraether lipids, number of cyclopentane rings and type of head groups, as a coping mechanism against environmental changes. The main biotechnological application of the membrane lipids of Sulfolobus spp. are so called archaeosomes. Archaeosomes are liposomes which are fully or partly generated from archaeal lipids and harbor the potential to be used as drug delivery systems for vaccines, proteins, peptides and nucleic acids. This review summarizes the influence of environmental parameters on the cell membrane of Sulfolobus spp. and the biotechnological applications of their membrane lipids.

scholarly journals Intact Polar and Core Glycerol Dibiphytanyl Glycerol Tetraether Lipids of Group I.1a and I.1b Thaumarchaeota in Soil

2012 ◽  
Vol 78 (19) ◽  
pp. 6866-6874 ◽  
Author(s):  
Jaap S. Sinninghe Damsté ◽  
W. Irene C. Rijpstra ◽  
Ellen C. Hopmans ◽  
Man-Young Jung ◽  
Jong-Geol Kim ◽  
...  
Keyword(s):  
Agricultural Soils ◽  
Membrane Lipids ◽  
Hydroxyl Group ◽  
Head Group ◽  
Aquatic Environments ◽  
Content Type ◽  
Group I ◽  
Head Groups ◽  
Intact Membrane ◽  
Tetraether Lipids

ABSTRACTEcological studies of thaumarchaeota often apply glycerol dibiphytanyl glycerol tetraether (GDGT)-based intact membrane lipids. However, these components have only been characterized for thaumarchaeota from aquatic environments. Thaumarchaeota have been shown to play an important role in the nitrogen cycle in soil as ammonium oxidizers, and GDGTs are common lipids encountered in soil. We report the core and intact polar lipid (IPL) GDGTs produced by three newly available thaumarchaeota isolated from grassland soil in Austria (“Nitrososphaera viennensis,” group I.1b) and enriched from agricultural soils in South Korea (“CandidatusNitrosoarchaeum koreensis” MY1, group I.1a; and “CandidatusNitrososphaera” strain JG1, group I.1b). The soil thaumarchaeota all synthesize crenarchaeol as their major core GDGT, in agreement with the fact that crenarchaeol has also been detected in thaumarchaeota from aquatic environments. The crenarchaeol regioisomer apparently is produced in significant quantities only by soil thaumarchaeota of the I.1b subgroup. In addition, GDGTs with 0 to 4 cyclopentane moieties and GDGTs containing an additional hydroxyl group were detected. The IPL head groups of their membrane lipids comprised mainly monohexose, dihexose, trihexose, phosphohexose, and hexose-phosphohexose moieties. The hexose-phosphohexose head group bound to crenarchaeol occurred in all soil thaumarchaeota, and this IPL is at present the only lipid that is detected in all thaumarchaeota analyzed so far. This specificity and its lability indicate that it is the most suitable biomarker lipid to trace living thaumarchaeota. This study, in combination with previous studies, also suggests that hydroxylated GDGTs occur in the I.1a, but not in the I.1b, subgroup of the thaumarchaeota.

Interaction of Different Extracts ofPrimula heterochromaStapf. with Red Blood Cell Membrane Lipids and Proteins: Antioxidant and Antihemolytic Effects

2012 ◽  
Vol 9 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Seyed Mohammad Nabavi ◽  
Seyed Fazel Nabavi ◽  
William N. Setzer ◽  
Heshmatollah Alinezhad ◽  
Mahboobeh Zare ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Membrane Lipids ◽  
Red Blood Cell Membrane

scholarly journals The fate and function of glycosphingolipid glucosylceramide

2003 ◽  
Vol 358 (1433) ◽  
pp. 869-873 ◽  
Author(s):  
Gerrit van Meer ◽  
Jasja Wolthoorn ◽  
Sophie Degroote
Keyword(s):  
Cellular Differentiation ◽  
Membrane Lipids ◽  
Early Stage ◽  
Cellular Level ◽  
Mature Stage ◽  
Storage Diseases ◽  
Head Groups ◽  
Biological Studies ◽  
Intracellular Membrane Transport ◽  
And Function

In higher eukaryotes, glucosylceramide is the simplest member and precursor of a fascinating class of membrane lipids, the glycosphingolipids. These lipids display an astounding variation in their carbohydrate head groups, suggesting that glycosphingolipids serve specialized functions in recognition processes. It is now realized that they are organized in signalling domains on the cell surface. They are of vital importance as, in their absence, embryonal development is inhibited at an early stage. Remarkably, individual cells can live without glycolipids, perhaps because their survival does not depend on glycosphingolipid–mediated signalling mechanisms. Still, these cells suffer from defects in intracellular membrane transport. Various membrane proteins do not reach their intracellular destination, and, indeed, some intracellular organelles do not properly differentiate to their mature stage. The fact that glycosphingolipids are required for cellular differentiation suggests that there are human diseases resulting from defects in glycosphingolipid synthesis. In addition, the same cellular differentiation processes may be affected by defects in the degradation of glycosphingolipids. At the cellular level, the pathology of glycosphingolipid storage diseases is not completely understood. Cell biological studies on the intracellular fate and function of glycosphingolipids may open new ways to understand and defeat not only lipid storage diseases, but perhaps other diseases that have not been connected to glycosphingolipids so far.

scholarly journals Insights into the Mode of Action of Chitosan as an Antibacterial Compound

2008 ◽  
Vol 74 (12) ◽  
pp. 3764-3773 ◽  
Author(s):  
Dina Raafat ◽  
Kristine von Bargen ◽  
Albert Haas ◽  
Hans-Georg Sahl
Keyword(s):  
Antimicrobial Activity ◽  
Cell Wall ◽  
Cell Membrane ◽  
Mode Of Action ◽  
Membrane Lipids ◽  
Expression Profiles ◽  
Transcriptional Response ◽  
Response Analysis ◽  
Sequence Of Events ◽  
Wide Range

ABSTRACT Chitosan is a polysaccharide biopolymer that combines a unique set of versatile physicochemical and biological characteristics which allow for a wide range of applications. Although its antimicrobial activity is well documented, its mode of action has hitherto remained only vaguely defined. In this work we investigated the antimicrobial mode of action of chitosan using a combination of approaches, including in vitro assays, killing kinetics, cellular leakage measurements, membrane potential estimations, and electron microscopy, in addition to transcriptional response analysis. Chitosan, whose antimicrobial activity was influenced by several factors, exhibited a dose-dependent growth-inhibitory effect. A simultaneous permeabilization of the cell membrane to small cellular components, coupled to a significant membrane depolarization, was detected. A concomitant interference with cell wall biosynthesis was not observed. Chitosan treatment of Staphylococcus simulans 22 cells did not give rise to cell wall lysis; the cell membrane also remained intact. Analysis of transcriptional response data revealed that chitosan treatment leads to multiple changes in the expression profiles of Staphylococcus aureus SG511 genes involved in the regulation of stress and autolysis, as well as genes associated with energy metabolism. Finally, a possible mechanism for chitosan's activity is postulated. Although we contend that there might not be a single classical target that would explain chitosan's antimicrobial action, we speculate that binding of chitosan to teichoic acids, coupled with a potential extraction of membrane lipids (predominantly lipoteichoic acid) results in a sequence of events, ultimately leading to bacterial death.

scholarly journals Novel archaeal macrocyclic diether core membrane lipids in a methane-derived carbonate crust from a mud volcano in the Sorokin Trough, NE Black Sea

Archaea ◽  
2003 ◽  
Vol 1 (3) ◽  
pp. 165-173 ◽  
Author(s):  
Alina Stadnitskaia ◽  
Marianne Baas ◽  
Michael K. Ivanov ◽  
Tjeerd C. E. Van Weering ◽  
Jaap S. Sinninghe Damsté
Keyword(s):  
Black Sea ◽  
Mass Spectra ◽  
Membrane Lipids ◽  
Mud Volcano ◽  
The Novel ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Carbonate Formation ◽  
Carbonate Crust ◽  
Archaeal Lipids

A methane-derived carbonate crust was collected from the recently discovered NIOZ mud volcano in the Sorokin Trough, NE Black Sea during the 11th Training-through-Research cruise of the R/V Professor Logachev. Among several specific bacterial and archaeal membrane lipids present in this crust, two novel macrocyclic diphytanyl glycerol diethers, containing one or two cyclopentane rings, were detected. Their structures were tentatively identified based on the interpretation of mass spectra, comparison with previously reported mass spectral data, and a hydrogenation experiment. This macrocyclic type of archaeal core membrane diether lipid has so far been identified only in the deep-sea hydrothermal vent methanogenMethanococcus jannaschii. Here, we provide the first evidence that these macrocyclic diethers can also contain internal cyclopentane rings. The molecular structure of the novel diethers resembles that of dibiphytanyl tetraethers in which biphytane chains, containing one and two pentacyclic rings, also occur. Such tetraethers were abundant in the crust. Compound-specific isotope measurements revealed δ13C values of –104 to –111‰ for these new archaeal lipids, indicating that they are derived from methanotrophic archaea acting within anaerobic methane-oxidizing consortia, which subsequently induce authigenic carbonate formation.

scholarly journals Removal of phospho-head groups of membrane lipids immobilizes voltage sensors of K+ channels

Nature ◽  
2008 ◽  
Vol 451 (7180) ◽  
pp. 826-829 ◽  
Author(s):  
Yanping Xu ◽  
Yajamana Ramu ◽  
Zhe Lu
Keyword(s):  
Membrane Lipids ◽  
K Channels ◽  
Voltage Sensors ◽  
Head Groups

Effect of herbicides on plant cell membrane lipids

1979 ◽  
pp. 45-76 ◽  
Author(s):  
C. M. Rivera ◽  
Donald Penner
Keyword(s):  
Cell Membrane ◽  
Plant Cell ◽  
Membrane Lipids

scholarly journals Can the subterranean fauna be used as proxy for past environmental changes? – the example of the Carpathians cave fauna

2018 ◽  
Vol 1 ◽  
Author(s):  
Oana Teodora Moldovan ◽  
Ionut Cornel Mirea ◽  
Marius Kenesz
Keyword(s):  
Environmental Changes ◽  
Regional Scale ◽  
Environmental Parameters ◽  
General View ◽  
Carpathian Mountains ◽  
Small Areas ◽  
The Carpathians ◽  
Cave Fauna ◽  
Historical Processes ◽  
Geological Units

Carpathian Mountains were one of the main refuge areas during the climate changes of the Pleistocene and the Holocene in Europe and one of the richest regions in the world in subterranean (caves and associated habitats) endemic species. Nevertheless, the Carpathian Mountains subterranean fauna importance is underestimated especially due to dispersed information on its diversity and the scarcity of molecular studies in the area. Here, we present a first general view of the cave fauna hotspot represented by the Romanian Carpathians and the geological and historical processes that shaped the patterns of subterranean distribution and diversity at regional scale. The Carpathians are an amalgam of various geological units with complex paleogeographical evolution that is reflected in completely different species assemblages dominated by unit specific fauna groups. Phylogeography of Coleoptera and environmental parameters are adding to the general view at regional scale and offer additional explanation for this exceptional subterranean diversification in a non-Mediterranean region. We also use the example of the Carpathians cave fauna as proxy for past environmental changes in the area. Troglobionts are endemic on small areas and by studying their present distributions and phylogeny, past processes of landscape evolution on the surface can be better understood.

scholarly journals Revised fractional abundances and warm-season temperatures substantially improve brGDGT calibrations in lake sediments

2021 ◽  
Author(s):  
Jonathan H. Raberg ◽  
David J. Harning ◽  
Sarah E. Crump ◽  
Greg de Wet ◽  
Aria Blumm ◽  
...  
Keyword(s):  
Lake Sediments ◽  
Lake Sediment ◽  
Membrane Lipids ◽  
Warm Season ◽  
Environmental Parameters ◽  
Structural Diversity ◽  
Temperature Conductivity ◽  
Advantages And Disadvantages ◽  
Natural Logarithm ◽  
Air Temperatures

Abstract. Distributions of branched glycerol dialkyl glycerol tetraethers (brGDGTs) are frequently employed for reconstructing terrestrial paleotemperatures from lake sediment archives. Although brGDGTs are globally ubiquitous, the microbial producers of these membrane lipids remain unknown, precluding a full understanding of the ways in which environmental parameters control their production and distribution. Here, we advance this understanding in three ways. First, we present 43 new high-latitude lake sites characterized by low mean annual air temperatures (MATs) and high seasonality, filling an important gap in the global dataset. Second, we introduce a new approach for analyzing brGDGT data in which compound fractional abundances (FAs) are calculated within structural groups based on methylation number, methylation position, and cyclization number. Finally, we perform linear and nonlinear regressions of the resulting FAs against a suite of environmental parameters in a compiled global lake sediment dataset (n = 182). We find that our approach deconvolves temperature, conductivity, and pH trends in brGDGTs without increasing calibration errors from the standard approach. We also find that it reveals novel patterns in brGDGT distributions and provides a methodology for investigating the biological underpinnings of their structural diversity. Warm-season temperature indices outperformed MAT in our regressions, with Months Above Freezing yielding the highest-performing model (adjusted R2 = 0.91, RMSE = 1.97 °C, n = 182). The natural logarithm of conductivity had the second-strongest relationship to brGDGT distributions (adjusted R2 = 0.83, RMSE = 0.66, n = 143), notably outperforming pH in our dataset (adjusted R2 = 0.73, RMSE = 0.57, n = 154) and providing a potential new proxy for paleohydrology applications. We recommend these calibrations for use in lake sediments globally, including at high latitudes, and detail the advantages and disadvantages of each.

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