Homeostatic Mechanisms in Micro-organisms

Homeostatic Mechanisms in Micro-organisms PDF Author: Roger Whittenbury
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 304

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Book Description
Being small and compartmentalized, most micro-organisms do not have the advantage that many large multicellular organisms possess. Consequently, a whole range of rapidly acting mechanisms have evolved in them. This symposium covered those mechanisms. The 44th FEMS Symposium covered the major environmental streses and the major compensating homeostatic mechanisms, highlighting the parallel strategies that have evolved, as well as the contrasting ones. The Symposium also considered practically useful means for utilising, or interfering with, homeostasis (e.g. use of antibiotics and some organic acid food preservatives to collapse homeostatic chemiosmotic gradiets and inhibition of repair.

Homeostatic Mechanisms in Micro-organisms

Homeostatic Mechanisms in Micro-organisms PDF Author: Roger Whittenbury
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 304

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Book Description
Being small and compartmentalized, most micro-organisms do not have the advantage that many large multicellular organisms possess. Consequently, a whole range of rapidly acting mechanisms have evolved in them. This symposium covered those mechanisms. The 44th FEMS Symposium covered the major environmental streses and the major compensating homeostatic mechanisms, highlighting the parallel strategies that have evolved, as well as the contrasting ones. The Symposium also considered practically useful means for utilising, or interfering with, homeostasis (e.g. use of antibiotics and some organic acid food preservatives to collapse homeostatic chemiosmotic gradiets and inhibition of repair.

Functions and Mechanisms of Bacterial Protein Homeostasis and Stress Responses

Functions and Mechanisms of Bacterial Protein Homeostasis and Stress Responses PDF Author: Axel Mogk
Publisher: Frontiers Media SA
ISBN: 2889741931
Category : Science
Languages : en
Pages : 334

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Book Description
The Cover Image for This Research Topic is Used With Permission of the Authors and Publishers of the Following Article: Winkler J, Seybert A, König L, Pruggnaller S, Haselmann U, Sourjik V, Weiss M, Frangakis AS, Mogk A, Bukau B.EMBO J. 2010 Mar 3;29(5):910-23. doi: 10.1038/emboj.2009.412. Epub 2010 Jan 21

Organismal Homeostasis

Organismal Homeostasis PDF Author: Christopher J. Paradise
Publisher:
ISBN: 9781606509739
Category : Science
Languages : en
Pages : 0

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Book Description
Organisms maintain homeostasis in a variety of ways. In the first part of this book, mammals are shown to regulate their body temperatures through homeostatic mechanisms. The data from thermoregulation experiments that demonstrated the role of neurons in body temperature homeostasis are examined. The second part of this book discusses how organisms allocate the limited energy that is available to them for survival, growth, or reproduction. Excess energy in individuals can translate to growth of populations: if enough remains after survival and growth, it can be allocated to reproduction. However, even closely related organisms may have different strategies for allocating resources that are dependent upon the environmental conditions in which they exist.

Microbial Energy Conversion

Microbial Energy Conversion PDF Author: Zhenhong Yuan
Publisher: Walter de Gruyter GmbH & Co KG
ISBN: 311042486X
Category : Technology & Engineering
Languages : en
Pages : 568

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Book Description
The book provides an overview on various microorganisms and their industrialization in energy conversion, such as ethanol fermentation, butanol fermentation, biogas fermentation and fossil energy conversion. It also covers microbial oil production, hydrogen production and electricity generation. The content is up to date and suits well for both researchers and industrial audiences.

Molecular Mechanisms of Copper Homeostasis in Gram-negative Bacteria

Molecular Mechanisms of Copper Homeostasis in Gram-negative Bacteria PDF Author: Alayna Michelle George Thompson
Publisher:
ISBN:
Category :
Languages : en
Pages : 178

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Book Description
Copper is a trace element utilized by organisms as a cofactor involved in redox chemistry, electron transport, photosynthesis, and oxidation reactions. In excess, copper is toxic; it can generate reactive oxygen species causing cellular damage, or poison other metalloproteins by replacing native metal cofactors. Gram-negative bacteria have developed homeostatic mechanisms to maintain the intracellular copper concentration in the face of changing environmental conditions. For Gram-negative enteric bacteria, like Esherichiacoli and Salmonella enterica serovar typhimurium, copper is encountered in industrial and institutional settings, where the metal is used as a broad-spectrum biocide. For environmental bacteria, such as the marine cyanobacterium Synechococcus sp. WH8102, copper stress occurs because human activity changes the concentration of copper in the ocean. This dissertation contains six chapters, relating four stories of our investigations into the molecular mechanisms of copper homeostasis in Gram-negative bacteria. Chapter I contains literature review and background on the implications of bacterial copper homeostasis. Chapter II reports our work investigating the expression of two E. coli proteins, CusF and CusB, upon copper stress; we show that CusF expresses at a ~10-fold molar excess over CusB. Chapter III describes a collaboration between our lab and Jose Argüello's lab at Worcester Polytechnic Institute, and we show that CusF can acquire Cu(I) from CopA. Our results from Chapters II and III show that CusF functions as a major copper chaperone in the periplasm of E. coli. Chapter IV details our work characterizing a novel protein from marine cyanobacteria, Synw_0921. Although Synw_0921 is believed to be involved in copper homeostasis, we show that it is an iron-sulfur cluster protein. Bioinformatic analysis suggests that Synw_0921 represents a new family of proteins that help marine cyanobacteria adapt to copper changes in their unique environment. Chapter V relates our work on CueR and GolS, two homologous sensor proteins with distinct metal-dependent transcriptional activation; we find that the activity cannot be explained by binding affinity differences. Chapter VI concludes with final thoughts on the intersection of biochemistry and molecular biology in the important process of understanding copper homeostasis.

Microbiomes of the Built Environment

Microbiomes of the Built Environment PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309449839
Category : Science
Languages : en
Pages : 318

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Book Description
People's desire to understand the environments in which they live is a natural one. People spend most of their time in spaces and structures designed, built, and managed by humans, and it is estimated that people in developed countries now spend 90 percent of their lives indoors. As people move from homes to workplaces, traveling in cars and on transit systems, microorganisms are continually with and around them. The human-associated microbes that are shed, along with the human behaviors that affect their transport and removal, make significant contributions to the diversity of the indoor microbiome. The characteristics of "healthy" indoor environments cannot yet be defined, nor do microbial, clinical, and building researchers yet understand how to modify features of indoor environmentsâ€"such as building ventilation systems and the chemistry of building materialsâ€"in ways that would have predictable impacts on microbial communities to promote health and prevent disease. The factors that affect the environments within buildings, the ways in which building characteristics influence the composition and function of indoor microbial communities, and the ways in which these microbial communities relate to human health and well-being are extraordinarily complex and can be explored only as a dynamic, interconnected ecosystem by engaging the fields of microbial biology and ecology, chemistry, building science, and human physiology. This report reviews what is known about the intersection of these disciplines, and how new tools may facilitate advances in understanding the ecosystem of built environments, indoor microbiomes, and effects on human health and well-being. It offers a research agenda to generate the information needed so that stakeholders with an interest in understanding the impacts of built environments will be able to make more informed decisions.

Recent Advances in γδ T Cell Biology: New Ligands, New Functions, and New Translational Perspectives

Recent Advances in γδ T Cell Biology: New Ligands, New Functions, and New Translational Perspectives PDF Author: Dieter Kabelitz
Publisher: Frontiers Media SA
ISBN: 2889197840
Category : Medicine (General)
Languages : en
Pages : 271

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Book Description
Gamma/delta (γδ) T-cells are a small subset of T-lymphocytes in the peripheral circulation but constitute a major T-cell population at other anatomical localizations such as the epithelial tissues. In contrast to conventional α/β T-cells, the available number of germline genes coding for T-cell receptor (TCR) variable elements of γδ T-cells is very small. Moreover, there is a prefential localization of γδ T-cells expressing given Vgamma and Vdelta genes in certain tissues. In humans, γδ T-cells expressing the Vg9Vd2-encoded TCR account for anywhere between 50 and >95% of peripheral blood γδ T-cells, whereas cells expressing non-Vd2 genes dominate in mucosal tissues. In mice, there is an ordered appearance of γδ T-cell „waves“ during embryonic development, resulting in preferential localization of γδ T-cells expressing distinct VgammaVdelta genes in the skin, the reproductive organs, or gut epithelia. The major function of γδ T-cells resides in local immunosurveillance and immune defense against infection and malignancy. This is supported by the identification of ligands that are selectively recognized by the γδ TCR. As an example, human Vgamma9Vdelta2 T-cells recognize phosphorylated metabolites („phosphoantigens“) that are secreted by many pathogens but can also be overproduced by tumor cells, providing a basis for a role of these γδ T-cells in both anti-infective and anti-tumor immunity. Similarly, the recognition of endothelial protein C receptor by human non-Vdelta2 γδ T-cells has recently been identified to provide a link for the role for such γδ T-cells in immunity against epithelial tumor cells and cytomegalovirus-infected endothelial cells. In addition to „classical“ functions such as cytokine production and cytotoxicity, recent studies suggest that subsets of γδ T-cells can exert additional functions such as regulatory activity and – quite surpisingly – „professional“ antigen-presenting capacity. It is currently not well known how this tremendous extent of functional plasticity is regulated and what is the extent of γδ TCR ligand diversity. Due to their non-MHC-restricted recognition of unusual stress-associated ligands, γδ T-cells have raised great interest as to their potential translational application in cell-based immunotherapy. Topics of this Research Focus include: Molecular insights into the activation and differentiation requirements of γδ T-cells, role of pyrophosphates and butyrophilin molecules for the activation of human γδ T-cells, role of γδ T-cells in tumor immunity and in other infectious and non-infectious diseases, and many others. We are most grateful to all colleagues who agreed to write a manuscript. Thanks to their contributions, this E-book presents an up-to-date overview on many facets of the still exciting γδ T-cells. Dieter Kabelitz & Julie Déchanet-Merville

Iron Uptake and Homeostasis in Microorganisms

Iron Uptake and Homeostasis in Microorganisms PDF Author: Pierre Cornelis
Publisher:
ISBN: 9781912530823
Category :
Languages : en
Pages :

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Book Description
In this book, an international team of authors presents a comprehensive collection of reviews on iron uptake and metabolism in various microorganisms including rhizobia, Bordetella, Shigella, E. coli, Erwinia, Vibrio, Aeromonas, Francisella, Bacteroides, Campylobacter, cyanobacteria, Bacillus, staphylococci and yeasts. An entire chapter is dedicated to siderophores and another to heme uptake. The volume provides an expert and timely summary of current knowledge, with a focus on molecular and genetic aspects, and highlights some of the most exciting recent developments. Aimed at research scient.

Concepts of Biology

Concepts of Biology PDF Author: Samantha Fowler
Publisher:
ISBN: 9789888407453
Category : Science
Languages : en
Pages : 618

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Book Description
Concepts of Biology is designed for the single-semester introduction to biology course for non-science majors, which for many students is their only college-level science course. As such, this course represents an important opportunity for students to develop the necessary knowledge, tools, and skills to make informed decisions as they continue with their lives. Rather than being mired down with facts and vocabulary, the typical non-science major student needs information presented in a way that is easy to read and understand. Even more importantly, the content should be meaningful. Students do much better when they understand why biology is relevant to their everyday lives. For these reasons, Concepts of Biology is grounded on an evolutionary basis and includes exciting features that highlight careers in the biological sciences and everyday applications of the concepts at hand.We also strive to show the interconnectedness of topics within this extremely broad discipline. In order to meet the needs of today's instructors and students, we maintain the overall organization and coverage found in most syllabi for this course. A strength of Concepts of Biology is that instructors can customize the book, adapting it to the approach that works best in their classroom. Concepts of Biology also includes an innovative art program that incorporates critical thinking and clicker questions to help students understand--and apply--key concepts.

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria

Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria PDF Author: Frans J. de Bruijn
Publisher: John Wiley & Sons
ISBN: 1119004896
Category : Science
Languages : en
Pages : 1472

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Book Description
Bacteria in various habitats are subject to continuously changing environmental conditions, such as nutrient deprivation, heat and cold stress, UV radiation, oxidative stress, dessication, acid stress, nitrosative stress, cell envelope stress, heavy metal exposure, osmotic stress, and others. In order to survive, they have to respond to these conditions by adapting their physiology through sometimes drastic changes in gene expression. In addition they may adapt by changing their morphology, forming biofilms, fruiting bodies or spores, filaments, Viable But Not Culturable (VBNC) cells or moving away from stress compounds via chemotaxis. Changes in gene expression constitute the main component of the bacterial response to stress and environmental changes, and involve a myriad of different mechanisms, including (alternative) sigma factors, bi- or tri-component regulatory systems, small non-coding RNA’s, chaperones, CHRIS-Cas systems, DNA repair, toxin-antitoxin systems, the stringent response, efflux pumps, alarmones, and modulation of the cell envelope or membranes, to name a few. Many regulatory elements are conserved in different bacteria; however there are endless variations on the theme and novel elements of gene regulation in bacteria inhabiting particular environments are constantly being discovered. Especially in (pathogenic) bacteria colonizing the human body a plethora of bacterial responses to innate stresses such as pH, reactive nitrogen and oxygen species and antibiotic stress are being described. An attempt is made to not only cover model systems but give a broad overview of the stress-responsive regulatory systems in a variety of bacteria, including medically important bacteria, where elucidation of certain aspects of these systems could lead to treatment strategies of the pathogens. Many of the regulatory systems being uncovered are specific, but there is also considerable “cross-talk” between different circuits. Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria is a comprehensive two-volume work bringing together both review and original research articles on key topics in stress and environmental control of gene expression in bacteria. Volume One contains key overview chapters, as well as content on one/two/three component regulatory systems and stress responses, sigma factors and stress responses, small non-coding RNAs and stress responses, toxin-antitoxin systems and stress responses, stringent response to stress, responses to UV irradiation, SOS and double stranded systems repair systems and stress, adaptation to both oxidative and osmotic stress, and desiccation tolerance and drought stress. Volume Two covers heat shock responses, chaperonins and stress, cold shock responses, adaptation to acid stress, nitrosative stress, and envelope stress, as well as iron homeostasis, metal resistance, quorum sensing, chemotaxis and biofilm formation, and viable but not culturable (VBNC) cells. Covering the full breadth of current stress and environmental control of gene expression studies and expanding it towards future advances in the field, these two volumes are a one-stop reference for (non) medical molecular geneticists interested in gene regulation under stress.