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Bacteria AND essential genes

Chijun Li, Brandon K Tan, Jinshi Zhao, Ziqiang Guan
Phosphatidylglycerol (PG) makes up 5-20% of the phospholipids of Escherichia coli and is essential for growth in wild-type cells. PG is synthesized from the dephosphorylation of its immediate precursor, phosphatidylglycerol phosphate (PGP) whose synthase in E. coli is PgsA. Using genetic, biochemical and highly sensitive mass spectrometric approaches, we identified an alternative mechanism for PG synthesis in E. coli that is PgsA independent. The reaction of synthesis involves the conversion of phosphatidylethanolamine and glycerol into PG and is catalyzed by ClsB, a phospholipase D-type cardiolipin synthase...
October 19, 2016: Journal of Biological Chemistry
Pooja Gopal, Michelle Yee, Jickky Sarathy, Jian Liang Low, Jansy P Sarathy, Firat Kaya, Véronique Dartois, Martin Gengenbacher, Thomas Dick
Pyrazinamide (PZA) is a critical component of first- and second-line treatments of tuberculosis (TB), yet its mechanism of action largely remains an enigma. We carried out a genetic screen to isolate Mycobacterium bovis BCG mutants resistant to pyrazinoic acid (POA), the bioactive derivative of PZA, followed by whole genome sequencing of 26 POA resistant strains. Rather than finding mutations in the proposed candidate targets fatty acid synthase I and ribosomal protein S1, we found resistance conferring mutations in two pathways: missense mutations in aspartate decarboxylase panD, involved in the synthesis of the essential acyl carrier coenzyme A (CoA), and frameshift mutations in the vitro nonessential polyketide synthase genes mas and ppsA-E, involved in the synthesis of the virulence factor phthiocerol dimycocerosate (PDIM)...
September 9, 2016: ACS Infectious Diseases
Hari Bhupathi Krishnan, Alaa Alaswad, Nathan Wayne Oehrle, Jason Gillman
Legumes form symbiotic association with soil-dwelling bacteria collectively called rhizobia. This association results in the formation of nodules, unique plant-derived organs, within which the rhizobia are housed. Rhizobia encoded-nitrogenase facilitates the conversation of atmospheric nitrogen into ammonia, which is utilized by the plants for its growth and development. Fatty acids have been shown to play an important role in root nodule symbiosis. In this study, we have investigated the role of Stearoyl-Acyl Carrier Protein Desaturase- isoform C (SACPD-C), a soybean enzyme that catalyzes the conversion of stearic acid into oleic acid, which is expressed in developing seeds and in nitrogen fixing nodules...
October 17, 2016: Molecular Plant-microbe Interactions: MPMI
Harald Marx, Catherine E Minogue, Dhileepkumar Jayaraman, Alicia L Richards, Nicholas W Kwiecien, Alireza F Sihapirani, Shanmugam Rajasekar, Junko Maeda, Kevin Garcia, Angel R Del Valle-Echevarria, Jeremy D Volkening, Michael S Westphall, Sushmita Roy, Michael R Sussman, Jean-Michel Ané, Joshua J Coon
Legumes are essential components of agricultural systems because they enrich the soil in nitrogen and require little environmentally deleterious fertilizers. A complex symbiotic association between legumes and nitrogen-fixing soil bacteria called rhizobia culminates in the development of root nodules, where rhizobia fix atmospheric nitrogen and transfer it to their plant host. Here we describe a quantitative proteomic atlas of the model legume Medicago truncatula and its rhizobial symbiont Sinorhizobium meliloti, which includes more than 23,000 proteins, 20,000 phosphorylation sites, and 700 lysine acetylation sites...
October 17, 2016: Nature Biotechnology
Mauricio H Pontes, Jinki Yeom, Eduardo A Groisman
The synthesis of ribosomes is regulated by both amino acid abundance and the availability of ATP, which regenerates guanosine triphosphate (GTP), powers ribosomes, and promotes transcription of rRNA genes. We now report that bacteria supersede both of these controls when experiencing low cytosolic magnesium (Mg(2+)), a divalent cation essential for ribosome stabilization and for neutralization of ATP's negative charge. We uncover a regulatory circuit that responds to low cytosolic Mg(2+) by promoting expression of proteins that import Mg(2+) and lower ATP amounts...
October 8, 2016: Molecular Cell
Teija Ojala, Pia K S Laine, Terhi Ahlroos, Jarna Tanskanen, Saara Pitkänen, Tuomas Salusjärvi, Matti Kankainen, Soile Tynkkynen, Lars Paulin, Petri Auvinen
Propionibacterium freudenreichii is a commercially important bacterium that is essential for the development of the characteristic eyes and flavor of Swiss-type cheeses. These bacteria grow actively and produce large quantities of flavor compounds during cheese ripening at warm temperatures but also appear to contribute to the aroma development during the subsequent cold storage of cheese. Here, we advance our understanding of the role of P. freudenreichii in cheese ripening by presenting the 2.68-Mbp annotated genome sequence of P...
September 26, 2016: International Journal of Food Microbiology
Na Han, Weiwen Yu, Yujun Qiang, Wen Zhang
Type IV secretion system (T4SS) can mediate the passage of macromolecules across cellular membranes and is essential for virulent and genetic material exchange among bacterial species. The Type IV Secretion Project 2.0 (T4SP 2.0) database is an improved and extended version of the platform released in 2013 aimed at assisting with the detection of Type IV secretion systems (T4SS) in bacterial genomes. This advanced version provides users with web server tools for detecting the existence and variations of T4SS genes online...
2016: Computational and Mathematical Methods in Medicine
Bingbing Zong, Wugang Liu, Yanyan Zhang, Xiangru Wang, Huanchun Chen, Chen Tan
In recent years, extraintestinal pathogenic Escherichia coli (ExPEC) has been found to pose a great threat to human and animal health, but its pathogenic mechanism is not fully understood yet. Capsular polysaccharide, an essential virulence factor in these bacteria, can damage the host immune system, and kpsM is a member of the gene cluster responsible for capsular polysaccharide synthesis. In this study, whole sequence alignment of the virulent strain PCN033 and the attenuated strain PCN061 revealed that kpsM exists in PCN033 but not in PCN061...
October 12, 2016: FEMS Microbiology Letters
Yi-Lung Chen, Chia-Hsiang Wang, Fu-Chun Yang, Wael Ismail, Po-Hsiang Wang, Chao-Jen Shih, Yu-Ching Wu, Yin-Ru Chiang
Numerous studies have reported the masculinization of freshwater wildlife exposed to androgens in polluted rivers. Microbial degradation is a crucial mechanism for eliminating steroid hormones from contaminated ecosystems. The aerobic degradation of testosterone was observed in various bacterial isolates. However, the ecophysiological relevance of androgen-degrading microorganisms in the environment is unclear. Here, we investigated the biochemical mechanisms and corresponding microorganisms of androgen degradation in aerobic sewage...
October 13, 2016: Scientific Reports
Laam Li, Sébastien P Faucher
The water-borne pathogen Legionella pneumophila (Lp) strongly expresses the lpg1659 gene in water. This gene encodes a hypothetical protein predicted to be a membrane protein using in silico analysis. While no conserved domains were identified in Lpg1659, similar proteins are found in many Legionella species and other aquatic bacteria. RT-qPCR showed that lpg1659 is positively regulated by the alternative sigma factor RpoS, which is essential for Lp to survive in water. These observations suggest an important role of this novel protein in the survival of Lp in water...
2016: Frontiers in Cellular and Infection Microbiology
Teik Min Chong, Wai-Fong Yin, Jian-Woon Chen, Samuel Mondy, Catherine Grandclément, Denis Faure, Yves Dessaux, Kok-Gan Chan
Trace metals are required in many cellular processes in bacteria but also induce toxic effects to cells when present in excess. As such, various forms of adaptive responses towards extracellular trace metal ions are essential for the survival and fitness of bacteria in their environment. A soil Pseudomonas putida, strain S13.1.2 has been isolated from French vineyard soil samples, and shown to confer resistance to copper ions. Further investigation revealed a high capacity to tolerate elevated concentrations of various heavy metals including nickel, cobalt, cadmium, zinc and arsenic...
December 2016: AMB Express
Jiaojiao Li, Shashank S Pawitwar, Barry P Rosen
Arsenic is the most pervasive environmental toxic substance. As a consequence of its ubiquity, nearly every organism has genes for resistance to inorganic arsenic. In bacteria these genes are found largely in bacterial arsenic resistance (ars) operons. Recently a parallel pathway for synthesis and degradation of methylated arsenicals has been identified. The arsM gene product encodes the ArsM (AS3MT in animals) As(iii) S-adenosylmethionine methyltransferase that methylates inorganic trivalent arsenite in three sequential steps to methylarsenite MAs(iii), dimethylarsenite (DMAs(iii) and trimethylarsenite (TMAs(iii))...
October 1, 2016: Metallomics: Integrated Biometal Science
Brent S Weber, Seth W Hennon, Meredith S Wright, Nichollas E Scott, Véronique de Berardinis, Leonard J Foster, Juan A Ayala, Mark D Adams, Mario F Feldman
: The type VI secretion system (T6SS) is a widespread secretory apparatus produced by Gram-negative bacteria that has emerged as a potent mediator of antibacterial activity during interbacterial interactions. Most Acinetobacter species produce a genetically conserved T6SS, although the expression and functionality of this system vary among different strains. Some pathogenic Acinetobacter baumannii strains activate this secretion system via the spontaneous loss of a plasmid carrying T6SS repressors...
October 11, 2016: MBio
Marina Borisova, Rosmarie Gaupp, Amanda Duckworth, Alexander Schneider, Désirée Dalügge, Maraike Mühleck, Denise Deubel, Sandra Unsleber, Wenqi Yu, Günther Muth, Markus Bischoff, Friedrich Götz, Christoph Mayer
: Peptidoglycan recycling is a metabolic process by which Gram-negative bacteria reutilize up to half of their cell wall within one generation during vegetative growth. Whether peptidoglycan recycling also occurs in Gram-positive bacteria has so far remained unclear. We show here that three Gram-positive model organisms, Staphylococcus aureus, Bacillus subtilis, and Streptomyces coelicolor, all recycle the sugar N-acetylmuramic acid (MurNAc) of their peptidoglycan during growth in rich medium...
October 11, 2016: MBio
Helena Pillich, Madhu Puri, Trinad Chakraborty
Listeria monocytogenes is a ubiquitously occurring gram-positive bacterium in the environment that causes listeriosis, one of the deadliest foodborne infections known today. It is a versatile facultative intracellular pathogen capable of growth within the host's cytosolic compartment. Following entry into the host cell, L. monocytogenes escapes from vacuolar compartments to the cytosol, where the bacterium begins a remarkable journey within the host cytoplasm, culminating in bacterial spread from cell to cell, to deeper tissues and organs...
September 21, 2016: Current Topics in Microbiology and Immunology
Rika Indri Astuti, Ryo Nasuno, Hiroshi Takagi
As a cellular signaling molecule, nitric oxide (NO) is widely conserved from microorganisms, such as bacteria, yeasts, and fungi, to higher eukaryotes including plants and mammals. NO is mainly produced by NO synthase (NOS) or nitrite reductase (NIR) activity. There are several NO detoxification systems, including NO dioxygenase (NOD) and S-nitrosoglutathione reductase (GSNOR). NO homeostasis based on the balance between NO synthesis and degradation is important for the regulation of its physiological functions because an excess level of NO causes nitrosative stress due to the high reactivity of NO and NO-derived compounds...
October 8, 2016: Applied Microbiology and Biotechnology
Kerri L Coon, Mark R Brown, Michael R Strand
Mosquitoes are insects of interest because several species vector disease-causing pathogens to humans and other vertebrates. We previously reported that mosquitoes from long-term laboratory cultures require living bacteria in their gut to develop, but development does not depend on particular species of bacteria. Here, we focused on three distinct but interrelated areas of study to better understand the role of bacteria in mosquito development by studying field and laboratory populations of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus from the Southeastern United States...
October 8, 2016: Molecular Ecology
Julia U Brandt, Frank Jakob, Jürgen Behr, Andreas J Geissler, Rudi F Vogel
BACKGROUND: Acetic acid bacteria (AAB) are well known producers of commercially used exopolysaccharides, such as cellulose and levan. Kozakia (K.) baliensis is a relatively new member of AAB, which produces ultra-high molecular weight levan from sucrose. Throughout cultivation of two K. baliensis strains (DSM 14400, NBRC 16680) on sucrose-deficient media, we found that both strains still produce high amounts of mucous, water-soluble substances from mannitol and glycerol as (main) carbon sources...
October 4, 2016: Microbial Cell Factories
Mazen S Bader, Mark Loeb, Annie A Brooks
Urinary tract infections (UTIs) caused by antibiotic-resistant Gram-negative bacteria are a growing concern due to limited therapeutic options. Gram-negative bacteria, specifically Enterobacteriaceae, are common causes of both community-acquired and hospital acquired UTIs. These organisms can acquire genes that encode for multiple antibiotic resistance mechanisms, including extended-spectrum-lactamases (ESBLs), AmpC- β -lactamase, and carbapenemases. The assessment of suspected UTI includes identification of characteristic symptoms or signs, urinalysis, dipstick or microscopic tests, and urine culture if indicated...
October 7, 2016: Postgraduate Medicine
John Paul Balmonte, Carol Arnosti, Sarah Underwood, Brent A McKee, Andreas Teske
Riverine bacterial communities play an essential role in the biogeochemical coupling of terrestrial and marine environments, transforming elements and organic matter in their journey from land to sea. However, precisely due to the fact that rivers receive significant terrestrial input, the distinction between resident freshwater taxa vs. land-derived microbes can often become ambiguous. Furthermore, ecosystem perturbations could introduce allochthonous microbial groups and reshape riverine bacterial communities...
2016: Frontiers in Microbiology
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