The electrifying physiology of Geobacter bacteria, 30 years on.
Abstract The family Geobacteraceae, with its only valid genus Geobacter, comprises deltaproteobacteria ubiquitous in soil, sediments, and subsurface environments where metal reduction is an active process. Research for almost three decades has provided novel insights into environmental processes and biogeochemical reactions not previously known to be carried out by microorganisms. At the heart of the environmental roles played by Geobacter bacteria is their ability to integrate redox pathways and regulatory checkpoints that maximize growth efficiency with electron donors derived from the decomposition of organic m...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Reguera G, Kashefi K Tags: Adv Microb Physiol Source Type: research

Hydrogenases and H2 metabolism in sulfate-reducing bacteria of the Desulfovibrio genus.
Abstract Hydrogen metabolism plays a central role in sulfate-reducing bacteria of the Desulfovibrio genus and is based on hydrogenases that catalyze the reversible conversion of protons into dihydrogen. These metabolically versatile microorganisms possess a complex hydrogenase system composed of several enzymes of both [FeFe]- and [NiFe]-type that can vary considerably from one Desulfovibrio species to another. This review covers the molecular and physiological aspects of hydrogenases and H2 metabolism in Desulfovibrio but focuses particularly on our model bacterium Desulfovibrio fructosovorans. The search of hydr...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Baffert C, Kpebe A, Avilan L, Brugna M Tags: Adv Microb Physiol Source Type: research

Regulation of organohalide respiration.
Abstract Organohalide respiration (OHR) is an anaerobic metabolism by which bacteria conserve energy with the use of halogenated compounds as terminal electron acceptors. Genes involved in OHR are organized in reductive dehalogenase (rdh) gene clusters and can be found in relatively high copy numbers in the genomes of organohalide-respiring bacteria (OHRB). The minimal rdh gene set is composed by rdhA and rdhB, encoding the catalytic enzyme involved in reductive dehalogenation and its putative membrane anchor, respectively. In this chapter, we present the major findings concerning the regulatory strategies develop...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Maillard J, Willemin MS Tags: Adv Microb Physiol Source Type: research

The function, biogenesis and regulation of the electron transport chains in Campylobacter jejuni: New insights into the bioenergetics of a major food-borne pathogen.
Abstract Campylobacter jejuni is a zoonotic Epsilonproteobacterium that grows in the gastrointestinal tract of birds and mammals, and is the most frequent cause of food-borne bacterial gastroenteritis worldwide. As an oxygen-sensitive microaerophile, C. jejuni has to survive high environmental oxygen tensions, adapt to oxygen limitation in the host intestine and resist host oxidative attack. Despite its small genome size, C. jejuni is a versatile and metabolically active pathogen, with a complex and highly branched set of respiratory chains allowing the use of a wide range of electron donors and alternative electr...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Taylor AJ, Kelly DJ Tags: Adv Microb Physiol Source Type: research

The plethora of membrane respiratory chains in the phyla of life.
Abstract The diversity of microbial cells is reflected in differences in cell size and shape, motility, mechanisms of cell division, pathogenicity or adaptation to different environmental niches. All these variations are achieved by the distinct metabolic strategies adopted by the organisms. The respiratory chains are integral parts of those strategies especially because they perform the most or, at least, most efficient energy conservation in the cell. Respiratory chains are composed of several membrane proteins, which perform a stepwise oxidation of metabolites toward the reduction of terminal electron acceptors...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Refojo PN, Sena FV, Calisto F, Sousa FM, Pereira MM Tags: Adv Microb Physiol Source Type: research

Reduction of hydrogen peroxide in gram-negative bacteria - bacterial peroxidases.
ta SR Abstract Bacteria display an array of enzymes to detoxify reactive oxygen species that cause damage to DNA and to other biomolecules leading to cell death. Hydrogen peroxide is one of these species, with endogenous and exogenous sources, such as lactic acid bacteria, oxidative burst of the immune system or chemical reactions at oxic-anoxic interfaces. The enzymes that detoxify hydrogen peroxide will be the focus of this review, with special emphasis on bacterial peroxidases that reduce hydrogen peroxide to water. Bacterial peroxidases are periplasmic cytochromes with either two or three c-type haems, which h...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Nóbrega CS, Pauleta SR Tags: Adv Microb Physiol Source Type: research

Formate hydrogenlyase: A group 4 [NiFe]-hydrogenase in tandem with a formate dehydrogenase.
Abstract Hydrogenase enzymes are currently under the international research spotlight due to emphasis on biologically produced hydrogen as one potential energy carrier to relinquish the requirement for 'fossil fuel' derived energy. Three major classes of hydrogenase exist in microbes all able to catalyze the reversible oxidation of dihydrogen to protons and electrons. These classes are defined by their active site metal content: [NiFe]-; [FeFe]- and [Fe]-hydrogenases. Of these the [NiFe]-hydrogenases have links to ancient forms of metabolism, utilizing hydrogen as the original source of reductant on Earth. This re...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Finney AJ, Sargent F Tags: Adv Microb Physiol Source Type: research

Bioenergetic aspects of archaeal and bacterial hydrogen metabolism.
Abstract Hydrogenases are metal-containing biocatalysts that reversibly convert protons and electrons to hydrogen gas. This reaction can contribute in different ways to the generation of the proton motive force (PMF) of a cell. One means of PMF generation involves reduction of protons on the inside of the cytoplasmic membrane, releasing H2 gas, which being without charge is freely diffusible across the cytoplasmic membrane, where it can be re-oxidized to release protons. A second route of PMF generation couples transfer of electrons derived from H2 oxidation to quinone reduction and concomitant proton uptake at th...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Pinske C Tags: Adv Microb Physiol Source Type: research

Stress-induced adaptive morphogenesis in bacteria.
Abstract Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful p...
Source: Advances in Microbial Physiology - May 29, 2019 Category: Microbiology Authors: Ultee E, Ramijan K, Dame RT, Briegel A, Claessen D Tags: Adv Microb Physiol Source Type: research

Host-Derived Nitric Oxide and Its Antibacterial Effects in the Urinary Tract.
Abstract Urinary tract infection (UTI) is one of the most common bacterial infections in humans, and the majority are caused by uropathogenic Escherichia coli (UPEC). The rising antibiotic resistance among UPEC and the frequent failure of antibiotics to effectively treat recurrent UTI and catheter-associated UTI motivate research on alternative ways of managing UTI. Abundant evidence indicates that the toxic radical nitric oxide (NO), formed by activation of the inducible nitric oxide synthase, plays an important role in host defence to bacterial infections, including UTI. The major source of NO production during ...
Source: Advances in Microbial Physiology - September 30, 2018 Category: Microbiology Authors: Svensson L, Poljakovic M, Demirel I, Sahlberg C, Persson K Tags: Adv Microb Physiol Source Type: research

Novel Antibacterials: Alternatives to Traditional Antibiotics.
Abstract With the advent of the global antimicrobial resistance (AMR) crisis, our arsenal of effective antibiotics is diminishing. The widespread use and misuse of antibiotics in human and veterinary medicine, compounded by the lack of novel classes of antibiotic in the pharmaceutical pipeline, has left a hole in our antibiotic armamentarium. Thus, alternatives to traditional antibiotics are being investigated, including two major groups of antibacterial agents, which have been extensively studied, phytochemicals and metals. Within these groups, there are several subclasses of compound/elements, including polyphen...
Source: Advances in Microbial Physiology - September 30, 2018 Category: Microbiology Authors: Betts JW, Hornsey M, La Ragione RM Tags: Adv Microb Physiol Source Type: research

Biotechnological Applications of Bioactive Peptides From Marine Sources.
A, Verde C Abstract This review is an overview on marine bioactive peptides with promising activities for the development of alternative drugs to fight human pathologies. In particular, we focus on potentially prolific producers of peptides in microorganisms, including sponge-associated bacteria and marine photoautotrophs such as microalgae and cyanobacteria. Microorganisms are still poorly explored for drug discovery, even if they are highly metabolically plastic and potentially amenable to culturing. This offers the possibility of obtaining a continuous source of bioactive compounds to satisfy the challenging d...
Source: Advances in Microbial Physiology - September 30, 2018 Category: Microbiology Authors: Giordano D, Costantini M, Coppola D, Lauritano C, Núñez Pons L, Ruocco N, di Prisco G, Ianora A, Verde C Tags: Adv Microb Physiol Source Type: research

Nitric Oxide Stress as a Metabolic Flux.
Abstract Nitric oxide (NO) is an antimicrobial metabolite produced by immune cells to prohibit infection. Due to its reactivity, NO has numerous reaction routes available to it in biological systems with some leading to cellular damage and others producing innocuous compounds. Pathogens have evolved resistance mechanisms toward NO, and many of these take the form of enzymes that chemically passivate the molecule. In essence, bacteria have channeled NO flux toward useful or harmless compounds, and away from pathways that damage cellular components. Pathogens devoid of detoxification enzymes have been found to have ...
Source: Advances in Microbial Physiology - September 30, 2018 Category: Microbiology Authors: Brynildsen MP Tags: Adv Microb Physiol Source Type: research

Antibiotic Lethality and Membrane Bioenergetics.
Abstract A growing body of research suggests bacterial metabolism and membrane bioenergetics affect the lethality of a broad spectrum of antibiotics. Electrochemical gradients spanning energy-transducing membranes are the foundation of the chemiosmotic hypothesis and are essential for life; accordingly, their dysfunction appears to be a critical factor in bacterial death. Proton flux across energy-transducing membranes is central for cellular homeostasis as vectorial proton translocation generates a proton motive force used for ATP synthesis, pH homeostasis, and maintenance of solute gradients. Our recent investig...
Source: Advances in Microbial Physiology - September 30, 2018 Category: Microbiology Authors: Voskuil MI, Covey CR, Walter ND Tags: Adv Microb Physiol Source Type: research

Reactive Cysteine Persulphides: Occurrence, Biosynthesis, Antioxidant Activity, Methodologies, and Bacterial Persulphide Signalling.
Abstract Cysteine hydropersulphide (CysSSH) is a cysteine derivative having one additional sulphur atom bound to a cysteinyl thiol group. Recent advances in the development of analytical methods for detection and quantification of persulphides and polysulphides have revealed the biological presence, in both prokaryotes and eukaryotes, of hydropersulphides in diverse forms such as CysSSH, homocysteine hydropersulphide, glutathione hydropersulphide, bacillithiol hydropersulphide, coenzyme A hydropersulphide, and protein hydropersulphides. Owing to the chemical reactivity of the persulphide moiety, biological systems...
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Sawa T, Ono K, Tsutsuki H, Zhang T, Ida T, Nishida M, Akaike T Tags: Adv Microb Physiol Source Type: research

Nitric Oxide, an Old Molecule With Noble Functions in Pseudomonas aeruginosa Biology.
Abstract Pseudomonas aeruginosa, a Gram-negative bacterium, is characterized by its versatility that enables persistent survival under adverse conditions. It can grow on diverse energy sources and readily acquire resistance to antimicrobial agents. As an opportunistic human pathogen, it also causes chronic infections inside the anaerobic mucus airways of cystic fibrosis patients. As a strict respirer, P. aeruginosa can grow by anaerobic nitrate ( [Formula: see text] ) respiration. Nitric oxide (NO) produced as an intermediate during anaerobic respiration exerts many important effects on the biological characterist...
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Toyofuku M, Yoon SS Tags: Adv Microb Physiol Source Type: research

Emerging Roles of Nitric Oxide Synthase in Bacterial Physiology.
Abstract Nitric oxide (NO) is a potent inhibitor of diverse cellular processes in bacteria. Therefore, it was surprising to discover that several bacterial species, primarily Gram-positive organisms, harboured a gene encoding nitric oxide synthase (NOS). Recent attempts to characterize bacterial NOS (bNOS) have resulted in the discovery of structural features that may allow it to function as a NO dioxygenase and produce nitrate in addition to NO. Consistent with this characterization, investigations into the biological function of bNOS have also emphasized a role for NOS-dependent nitrate and nitrite production in...
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Hutfless EH, Chaudhari SS, Thomas VC Tags: Adv Microb Physiol Source Type: research

Anaerobic Bacterial Response to Nitrosative Stress.
Abstract This chapter provides an overview of current knowledge of how anaerobic bacteria protect themselves against nitrosative stress. Nitric oxide (NO) is the primary source of this stress. Aerobically its removal is an oxidative process, whereas reduction is required anaerobically. Mechanisms required to protect aerobic and anaerobic bacteria are therefore different. Several themes recur in the review. First, how gene expression is regulated often provides clues to the physiological function of the gene products. Second, the physiological significance of reports based upon experiments under extreme conditions ...
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Cole JA Tags: Adv Microb Physiol Source Type: research

Nitric Oxide Signalling in Yeast.
This article reviews NO metabolism (synthesis, degradation) and its regulation in yeast. The physiological roles of NO in yeast, including the oxidative stress response, are also discussed. Such investigations into NO signalling are essential for understanding how NO modulates the genetics and physiology of yeast. In addition to being responsible for the pathology and pharmacology of various degenerative diseases, NO signalling may be a potential target for the construction and engineering of industrial yeast strains. PMID: 29778216 [PubMed - in process] (Source: Advances in Microbial Physiology)
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Astuti RI, Nasuno R, Takagi H Tags: Adv Microb Physiol Source Type: research

The Inflammasome: Regulation of Nitric Oxide and Antimicrobial Host Defence.
Abstract Nitric oxide (NO) is a gaseous signalling molecule that plays diverse physiological functions including antimicrobial host defence. During microbial infection, NO is synthesized by inducible NO synthase (iNOS), which is expressed by host immune cells through the recognition of microbial pattern molecules. Therefore, sensing pathogens or their pattern molecules by pattern recognition receptors (PRRs), which are located at the cell surface, endosomal and phagosomal compartment, or in the cytosol, is key in inducing iNOS and eliciting antimicrobial host defence. A group of cytosolic PRRs is involved in induc...
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Ramachandran RA, Lupfer C, Zaki H Tags: Adv Microb Physiol Source Type: research

Preface.
PMID: 29778218 [PubMed - in process] (Source: Advances in Microbial Physiology)
Source: Advances in Microbial Physiology - May 23, 2018 Category: Microbiology Authors: Poole RK Tags: Adv Microb Physiol Source Type: research

The Microbiology of Ruthenium Complexes.
Abstract Ruthenium is seldom mentioned in microbiology texts, due to the fact that this metal has no known, essential roles in biological systems, nor is it generally considered toxic. Since the fortuitous discovery of cisplatin, first as an antimicrobial agent and then later employed widely as an anticancer agent, complexes of other platinum group metals, such as ruthenium, have attracted interest for their medicinal properties. Here, we review at length how ruthenium complexes have been investigated as potential antimicrobial, antiparasitic and chemotherapeutic agents, in addition to their long and well-establis...
Source: Advances in Microbial Physiology - August 2, 2017 Category: Microbiology Authors: Southam HM, Butler JA, Chapman JA, Poole RK Tags: Adv Microb Physiol Source Type: research

Mechanism and Role of Globin-Coupled Sensor Signalling.
Abstract The discovery of the globin-coupled sensor (GCS) family of haem proteins has provided new insights into signalling proteins and pathways by which organisms sense and respond to changing oxygen levels. GCS proteins consist of a sensor globin domain linked to a variety of output domains, suggesting roles in controlling numerous cellular pathways, and behaviours in response to changing oxygen concentration. Members of this family of proteins have been identified in the genomes of numerous organisms and characterization of GCS with output domains, including methyl accepting chemotaxis proteins, kinases, and d...
Source: Advances in Microbial Physiology - August 2, 2017 Category: Microbiology Authors: Walker JA, Rivera S, Weinert EE Tags: Adv Microb Physiol Source Type: research

Cytochrome bd and Gaseous Ligands in Bacterial Physiology.
ve; A Abstract Cytochrome bd is a unique prokaryotic respiratory terminal oxidase that does not belong to the extensively investigated family of haem-copper oxidases (HCOs). The enzyme catalyses the four-electron reduction of O2 to 2H2O, using quinols as physiological reducing substrates. The reaction is electrogenic and cytochrome bd therefore sustains bacterial energy metabolism by contributing to maintain the transmembrane proton motive force required for ATP synthesis. As compared to HCOs, cytochrome bd displays several distinctive features in terms of (i) metal composition (it lacks Cu and harbours a d-type h...
Source: Advances in Microbial Physiology - August 2, 2017 Category: Microbiology Authors: Forte E, Borisov VB, Vicente JB, Giuffrè A Tags: Adv Microb Physiol Source Type: research

Haem-Based Sensors of O2: Lessons and Perspectives.
Abstract Haem-based sensors have emerged during the last 15 years as being a large family of proteins that occur in all kingdoms of life. These sensors are responsible mainly for detecting binding of O2, CO and NO and reporting the ligation status to an output domain with an enzymatic or macromolecule-binding property. A myriad of biological functions have been associated with these sensors, which are involved in vasodilation, bacterial symbiosis, chemotaxis and biofilm formation, among others. Here, we critically review several bacterial systems for O2 sensing that are extensively studied in many respects, focusi...
Source: Advances in Microbial Physiology - August 2, 2017 Category: Microbiology Authors: Sousa EHS, Gilles-Gonzalez MA Tags: Adv Microb Physiol Source Type: research

The Role of Plant Growth-Promoting Bacteria in Metal Phytoremediation.
Abstract Phytoremediation is a promising technology that uses plants and their associated microbes to clean up contaminants from the environment. In recent years, phytoremediation assisted by plant growth-promoting bacteria (PGPB) has been highly touted for cleaning up toxic metals from soil. PGPB include rhizospheric bacteria, endophytic bacteria and the bacteria that facilitate phytoremediation by other means. This review provides information about the traits and mechanisms possessed by PGPB that improve plant metal tolerance and growth, and illustrate mechanisms responsible for plant metal accumulation/transloc...
Source: Advances in Microbial Physiology - August 2, 2017 Category: Microbiology Authors: Kong Z, Glick BR Tags: Adv Microb Physiol Source Type: research

Bacterial Haemoprotein Sensors of NO: H-NOX and NosP.
Abstract Low concentrations of nitric oxide (NO) modulate varied behaviours in bacteria including biofilm dispersal and quorum sensing-dependent light production. H-NOX (haem-nitric oxide/oxygen binding) is a haem-bound protein domain that has been shown to be involved in mediating these bacterial responses to NO in several organisms. However, many bacteria that respond to nanomolar concentrations of NO do not contain an annotated H-NOX domain. Nitric oxide sensing protein (NosP), a newly discovered bacterial NO-sensing haemoprotein, may fill this role. The focus of this review is to discuss structure, ligand bind...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Bacon B, Nisbett LM, Boon E Tags: Adv Microb Physiol Source Type: research

Metal-Based Combinations That Target Protein Synthesis by Fungi.
ry SV Abstract A wide range of fungicides (or antifungals) are used in agriculture and medicine, with activities against a spectrum of fungal pathogens. Unfortunately, the evolution of fungicide resistance has become a major issue. Therefore, there is an urgent need for new antifungal treatments. Certain metals have been used for decades as efficient fungicides in agriculture. However, concerns over metal toxicity have escalated over this time. Recent studies have revealed that metals like copper and chromate can impair functions required for the fidelity of protein synthesis in fungi. This occurs through differen...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Vallières C, Avery SV Tags: Adv Microb Physiol Source Type: research

Transition Metal Homeostasis in Streptococcus pyogenes and Streptococcus pneumoniae.
Abstract Trace metals such as Fe, Mn, Zn and Cu are essential for various biological functions including proper innate immune function. The host immune system has complicated and coordinated mechanisms in place to either starve and/or overload invading pathogens with various metals to combat the infection. Here, we discuss the roles of Fe, Mn and Zn in terms of nutritional immunity, and also the roles of Cu and Zn in metal overload in relation to the physiology and pathogenesis of two human streptococcal species, Streptococcus pneumoniae and Streptococcus pyogenes. S. pneumoniae is a major human pathogen that is c...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Turner AG, Ong CY, Walker MJ, Djoko KY, McEwan AG Tags: Adv Microb Physiol Source Type: research

Copper and Antibiotics: Discovery, Modes of Action, and Opportunities for Medicinal Applications.
Abstract Copper is a ubiquitous element in the environment as well as living organisms, with its redox capabilities and complexation potential making it indispensable for many cellular functions. However, these same properties can be highly detrimental to prokaryotes and eukaryotes when not properly controlled, damaging many biomolecules including DNA, lipids, and proteins. To restrict free copper concentrations, all bacteria have developed mechanisms of resistance, sequestering and effluxing labile copper to minimize its deleterious effects. This weakness is actively exploited by phagocytes, which utilize a coppe...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Dalecki AG, Crawford CL, Wolschendorf F Tags: Adv Microb Physiol Source Type: research

Metal Resistance and Its Association With Antibiotic Resistance.
Abstract Antibiotic resistance is recognised as a major global threat to public health by the World Health Organization. Currently, several hundred thousand deaths yearly can be attributed to infections with antibiotic-resistant bacteria. The major driver for the development of antibiotic resistance is considered to be the use, misuse and overuse of antibiotics in humans and animals. Nonantibiotic compounds, such as antibacterial biocides and metals, may also contribute to the promotion of antibiotic resistance through co-selection. This may occur when resistance genes to both antibiotics and metals/biocides are c...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Pal C, Asiani K, Arya S, Rensing C, Stekel DJ, Larsson DGJ, Hobman JL Tags: Adv Microb Physiol Source Type: research

The Role of Intermetal Competition and Mis-Metalation in Metal Toxicity.
Abstract The metals manganese, iron, cobalt, nickel, copper and zinc are essential for almost all bacteria, but their precise metal requirements vary by species, by ecological niche and by growth condition. Bacteria thus must acquire each of these essential elements in sufficient quantity to satisfy their cellular demand, but in excess these same elements are toxic. Metal toxicity has been exploited by humanity for centuries, and by the mammalian immune system for far longer, yet the mechanisms by which these elements cause toxicity to bacteria are not fully understood. There has been a resurgence of interest in m...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Barwinska-Sendra A, Waldron KJ Tags: Adv Microb Physiol Source Type: research

Manganese in Marine Microbiology.
Abstract The importance of manganese in the physiology of marine microbes, the biogeochemistry of the ocean and the health of microbial communities of past and present is emerging. Manganese is distributed widely throughout the global ocean, taking the form of an essential antioxidant (Mn(2+)), a potent oxidant (Mn(3+)) and strong adsorbent (Mn oxides) sequestering disproportionately high levels of trace metals and nutrients in comparison to the surrounding seawater. Manganese is, in fact, linked to nearly all other elemental cycles and intricately involved in the health, metabolism and function of the ocean's mic...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Hansel CM Tags: Adv Microb Physiol Source Type: research

Nutritional Immunity and Fungal Pathogenesis: The Struggle for Micronutrients at the Host-Pathogen Interface.
Abstract All living organisms require certain micronutrients such as iron, zinc, manganese and copper for cellular function and growth. For human pathogens however, the maintenance of metal ion homeostasis is particularly challenging. This is because the mammalian host actively enforces extremes of micronutrient availability on potential microbial invaders-processes collectively termed nutritional immunity. The role of iron sequestration in controlling microbial infections is well established and, more recently, the importance of other metals including zinc, manganese and copper has been recognised. In this chapte...
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Malavia D, Crawford A, Wilson D Tags: Adv Microb Physiol Source Type: research

Preface.
PMID: 28528653 [PubMed - in process] (Source: Advances in Microbial Physiology)
Source: Advances in Microbial Physiology - May 24, 2017 Category: Microbiology Authors: Poole RK Tags: Adv Microb Physiol Source Type: research

The Journey of Lipoproteins Through the Cell: One Birthplace, Multiple Destinations.
Abstract Bacterial lipoproteins are a very diverse group of proteins characterized by the presence of an N-terminal lipid moiety that serves as a membrane anchor. Lipoproteins have a wide variety of crucial functions, ranging from envelope biogenesis to stress response. In Gram-negative bacteria, lipoproteins can be targeted to various destinations in the cell, including the periplasmic side of the cytoplasmic or outer membrane, the cell surface or the external milieu. The sorting mechanisms have been studied in detail in Escherichia coli, but exceptions to the rules established in this model bacterium exist in ot...
Source: Advances in Microbial Physiology - October 12, 2016 Category: Microbiology Authors: Szewczyk J, Collet JF Tags: Adv Microb Physiol Source Type: research

The Impact of Gene Silencing on Horizontal Gene Transfer and Bacterial Evolution.
Abstract The H-NS family of DNA-binding proteins is the subject of intense study due to its important roles in the regulation of horizontally acquired genes critical for virulence, antibiotic resistance, and metabolism. Xenogeneic silencing proteins, typified by the H-NS protein of Escherichia coli, specifically target and downregulate expression from AT-rich genes by selectively recognizing specific structural features unique to the AT-rich minor groove. In doing so, these proteins facilitate bacterial evolution; enabling these cells to engage in horizontal gene transfer while buffering potential any detrimental ...
Source: Advances in Microbial Physiology - October 12, 2016 Category: Microbiology Authors: Navarre WW Tags: Adv Microb Physiol Source Type: research

Polar Marine Microorganisms and Climate Change.
Abstract The large diversity of marine microorganisms harboured by oceans plays an important role in planet sustainability by driving globally important biogeochemical cycles; all primary and most secondary production in the oceans is performed by microorganisms. The largest part of the planet is covered by cold environments; consequently, cold-adapted microorganisms have crucial functional roles in globally important environmental processes and biogeochemical cycles cold-adapted extremophiles are a remarkable model to shed light on the molecular basis of survival at low temperature. The indigenous populations of ...
Source: Advances in Microbial Physiology - October 12, 2016 Category: Microbiology Authors: Verde C, Giordano D, Bellas CM, di Prisco G, Anesio AM Tags: Adv Microb Physiol Source Type: research

The Making and Taking of Lipids: The Role of Bacterial Lipid Synthesis and the Harnessing of Host Lipids in Bacterial Pathogenesis.
Abstract In order to survive environmental stressors, including those induced by growth in the human host, bacterial pathogens will adjust their membrane physiology accordingly. These physiological changes also include the use of host-derived lipids to alter their own membranes and feed central metabolic pathways. Within the host, the pathogen is exposed to many stressful stimuli. A resulting adaptation is for pathogens to scavenge the host environment for readily available lipid sources. The pathogen takes advantage of these host-derived lipids to increase or decrease the rigidity of their own membranes, to provi...
Source: Advances in Microbial Physiology - October 12, 2016 Category: Microbiology Authors: Fozo EM, Rucks EA Tags: Adv Microb Physiol Source Type: research

Oxygen and Nitrate Respiration in Streptomyces coelicolor A3(2).
Abstract Streptomyces species belong to the phylum Actinobacteria and can only grow with oxygen as a terminal electron acceptor. Like other members of this phylum, such as corynebacteria and mycobacteria, the aerobic respiratory chain lacks a soluble cytochrome c. It is therefore implicit that direct electron transfer between the cytochrome bc1 and the cytochrome aa3 oxidase complexes occurs. The complex developmental cycle of streptomycetes manifests itself in the production of spores, which germinate in the presence of oxygen into a substrate mycelium that greatly facilitates acquisition of nutrients necessary t...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Sawers RG, Falke D, Fischer M Tags: Adv Microb Physiol Source Type: research

Anaerobic Metabolism in Haloferax Genus: Denitrification as Case of Study.
te MJ Abstract A number of species of Haloferax genus (halophilic archaea) are able to grow microaerobically or even anaerobically using different alternative electron acceptors such as fumarate, nitrate, chlorate, dimethyl sulphoxide, sulphide and/or trimethylamine. This metabolic capability is also shown by other species of the Halobacteriaceae and Haloferacaceae families (Archaea domain) and it has been mainly tested by physiological studies where cell growth is observed under anaerobic conditions in the presence of the mentioned compounds. This work summarises the main reported features on anaerobic metabolism...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Torregrosa-Crespo J, Martínez-Espinosa RM, Esclapez J, Bautista V, Pire C, Camacho M, Richardson DJ, Bonete MJ Tags: Adv Microb Physiol Source Type: research

Mechanisms of Bacterial Extracellular Electron Exchange.
Abstract The biochemical mechanisms by which microbes interact with extracellular soluble metal ions and insoluble redox-active minerals have been the focus of intense research over the last three decades. The process presents two challenges to the microorganism. Firstly, electrons have to be transported at the cell surface, which in Gram-negative bacteria presents an additional problem of electron transfer across the ~6nm of the outer membrane. Secondly, the electrons must be transferred to or from the terminal electron acceptors or donors. This review covers the known mechanisms that bacteria use to transport el...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: White GF, Edwards MJ, Gomez-Perez L, Richardson DJ, Butt JN, Clarke TA Tags: Adv Microb Physiol Source Type: research

Cooperation of Secondary Transporters and Sensor Kinases in Transmembrane Signalling: The DctA/DcuS and DcuB/DcuS Sensor Complexes of Escherichia coli.
l C Abstract Many membrane-bound sensor kinases require accessory proteins for function. The review describes functional control of membrane-bound sensors by transporters. The C4-dicarboxylate sensor kinase DcuS requires the aerobic or anaerobic C4-dicarboxylate transporters DctA or DcuB, respectively, for function and forms DctA/DcuS or DcuB/DcuS sensor complexes. Free DcuS is in the permanent (ligand independent) ON state. The DctA/DcuS and DcuB/DcuS complexes, on the other hand, control expression in response to C4-dicarboxylates. In DctA/DcuS, helix 8b of DctA and the PASC domain of DcuS are involved in intera...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Unden G, Wörner S, Monzel C Tags: Adv Microb Physiol Source Type: research

Pivotal Role of Iron in the Regulation of Cyanobacterial Electron Transport.
We present here the major mechanism used by cyanobacteria to couple iron homeostasis to the regulation of electron transport, making special emphasis in processes specific in those organisms. PMID: 27134024 [PubMed - in process] (Source: Advances in Microbial Physiology)
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: González A, Sevilla E, Bes MT, Peleato ML, Fillat MF Tags: Adv Microb Physiol Source Type: research

Bacterial Electron Transfer Chains Primed by Proteomics.
Abstract Electron transport phosphorylation is the central mechanism for most prokaryotic species to harvest energy released in the respiration of their substrates as ATP. Microorganisms have evolved incredible variations on this principle, most of these we perhaps do not know, considering that only a fraction of the microbial richness is known. Besides these variations, microbial species may show substantial versatility in using respiratory systems. In connection herewith, regulatory mechanisms control the expression of these respiratory enzyme systems and their assembly at the translational and posttranslational...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Wessels HJ, de Almeida NM, Kartal B, Keltjens JT Tags: Adv Microb Physiol Source Type: research

Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria: Physiology and Regulatory Mechanisms.
Abstract Nitrous oxide (N2O) is an important greenhouse gas (GHG) with substantial global warming potential and also contributes to ozone depletion through photochemical nitric oxide (NO) production in the stratosphere. The negative effects of N2O on climate and stratospheric ozone make N2O mitigation an international challenge. More than 60% of global N2O emissions are emitted from agricultural soils mainly due to the application of synthetic nitrogen-containing fertilizers. Thus, mitigation strategies must be developed which increase (or at least do not negatively impact) on agricultural efficiency whilst decrea...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Torres MJ, Simon J, Rowley G, Bedmar EJ, Richardson DJ, Gates AJ, Delgado MJ Tags: Adv Microb Physiol Source Type: research

The Model [NiFe]-Hydrogenases of Escherichia coli.
Abstract In Escherichia coli, hydrogen metabolism plays a prominent role in anaerobic physiology. The genome contains the capability to produce and assemble up to four [NiFe]-hydrogenases, each of which are known, or predicted, to contribute to different aspects of cellular metabolism. In recent years, there have been major advances in the understanding of the structure, function, and roles of the E. coli [NiFe]-hydrogenases. The membrane-bound, periplasmically oriented, respiratory Hyd-1 isoenzyme has become one of the most important paradigm systems for understanding an important class of oxygen-tolerant enzymes...
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Sargent F Tags: Adv Microb Physiol Source Type: research

Preface.
PMID: 27134028 [PubMed - in process] (Source: Advances in Microbial Physiology)
Source: Advances in Microbial Physiology - May 4, 2016 Category: Microbiology Authors: Poole RK Tags: Adv Microb Physiol Source Type: research

Cytochromes c': Structure, Reactivity and Relevance to Haem-Based Gas Sensing.
Abstract Cytochromes c' are a group of class IIa cytochromes with pentacoordinate haem centres and are found in photosynthetic, denitrifying and methanotrophic bacteria. Their function remains unclear, although roles in nitric oxide (NO) trafficking during denitrification or in cellular defence against nitrosoative stress have been proposed. Cytochromes c' are typically dimeric with each c-type haem-containing monomer folding as a four-α-helix bundle. Their hydrophobic and crowded distal sites impose severe restrictions on the binding of distal ligands, including diatomic gases. By contrast, NO binds to the ...
Source: Advances in Microbial Physiology - December 4, 2015 Category: Microbiology Authors: Hough MA, Andrew CR Tags: Adv Microb Physiol Source Type: research

Bridging Theory and Experiment to Address Structural Properties of Truncated Haemoglobins: Insights from Thermobifida fusca HbO.
Abstract In this chapter, we will discuss the paradigmatic case of Thermobifida fusca (Tf-trHb) HbO in its ferrous and ferric states and its behaviour towards a battery of possible ligands. This choice was dictated by the fact that it has been one of the most extensively studied truncated haemoglobins, both in terms of spectroscopic and molecular dynamics studies. Tf-trHb typifies the structural properties of group II trHbs, as the active site is characterized by a highly polar distal environment in which TrpG8, TyrCD1, and TyrB10 provide three potential H-bond donors in the distal cavity capable of stabilizing th...
Source: Advances in Microbial Physiology - December 4, 2015 Category: Microbiology Authors: Howes BD, Boechi L, Boffi A, Estrin DE, Smulevich G Tags: Adv Microb Physiol Source Type: research