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Iron bacteria

Dávid Szamosvári, Sina Rütschlin, Thomas Böttcher
Bacteria engage in numerous collaborative and competitive interactions, which are often mediated by small molecule metabolites. Bacterial competition involves for example the production of compounds that effectively kill or inhibit growth of their neighbours but also the secretion of siderophores that allow securing the essential and fiercely embattled resource of ferric iron. Yet, the enormous diversity of metabolites produced has remained puzzling in many cases. We here present examples of both types of competition from our recent work...
March 15, 2018: Organic & Biomolecular Chemistry
Jana Kisková, Zuzana Perháčová, Ladislav Vlčko, Jana Sedláková, Simona Kvasnová, Peter Pristaš
Although neutral mine drainage is the less frequent subject of the interest than acid mine drainage, it can have adverse environmental effects caused mainly by precipitation of dissolved Fe. The aim of the study was to characterize the composition of bacterial population in environment with high concentration of iron and sulfur compounds represented by neutral mine drainage water of Elizabeth's shaft, Slovinky (Slovakia). Direct microscopic observations, cultivation methods, and 454 pyrosequencing of the 16S rRNA gene amplicons were used to examine the bacterial population...
March 12, 2018: Current Microbiology
Guangsheng Qian, Linlin Ye, Liang Li, Xiaomin Hu, Binhui Jiang, Xin Zhao
This study proposed a periodic reversal bio-electrocoagulation system (PRBES) with Fe-C electrodes and three other control systems and explored their denitrification mechanism. The experimental results illustrated that iron ions contributed to increasing biomass and denitrifying bacteria and that the electric field may enhance the nitrogen transfer rate and enzyme activities. The dominant bacterial genera in the four systems were the Enterobacter (32.75%), Thauera (9.29%), Paracoccus (8.54%), Hyphomicrobium (5...
February 27, 2018: Bioresource Technology
Luis G Vargas Buonfiglio, Jennifer A Borcherding, Mark Frommelt, Gavin J Parker, Bryce Duchman, Oriana G Vanegas Calderón, Ruth Fernandez-Ruiz, Julio E Noriega, Elizabeth A Stone, Alicia K Gerke, Joseph Zabner, Alejandro P Comellas
BACKGROUND: Smoking is a leading cause of respiratory infections worldwide. Tobacco particulate matter disrupts iron homeostasis in the lungs and increases the iron content in the airways of smokers. The airway epithelia secrete lactoferrin to quench iron required for bacteria to proliferate and cause lung infections. We hypothesized that smokers would have increased bacterial growth and biofilm formation via iron lactoferrin imbalance. METHODS: We collected bronchoalveolar lavage (BAL) samples from non-smokers and smokers...
March 10, 2018: Respiratory Research
Manisha Chownk, Jashandeep Kaur, Kashmir Singh, Jagdeep Kaur
AIM: mbtJ from Mycobacterium tuberculosis H37Rv is a member of mbt A-J operon required for mycobactin biogenesis. MATERIALS & METHODS: The esterase/acetyl-hydrolase activity of mbtJ was determined by pNP-esters/native-PAGE and expression under iron stress by quantitative-PCR. Effect of gene on growth/survival of Mycobacterium was studied using antisense. Its effect on morphology, growth/infection was studied in Mycobacterium smegmatis. RESULTS: It showed acetyl hydrolase/esterase activity at pH 8...
March 9, 2018: Future Microbiology
Yunqiao Li, Dong Yang, Shang Wang, Chenyu Li, Bin Xue, Lin Yang, Zhiqiang Shen, Min Jin, Jingfeng Wang, Zhigang Qiu
While nanoparticles exert bactericidal effects through the generation of reactive oxygen species (ROS), the processes of the internalization of and the direct physical damage caused by iron oxide nanoparticles are not completely clear. We hypothesize that direct physical or mechanical damage of the cell membrane and cytoplasmic integrity by nanoparticles is another major cause of bacterial death besides ROS. The aim of this study is to investigate the process of the internalization of iron oxide nanoparticles, and to evaluate the effect of direct physical or mechanical damage on bacterial cell growth and death...
March 8, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Abhishek Mishra
Background: The genus Mycobacterium has an ability to persist in hostile environments for years before its reactivation in favorable conditions. The major bottleneck in decades of mycobacterial research is a poor understanding of molecular mechanism which assists bacteria to attain dormancy and reactivation later. Methods: In this study, hydroxyl radical was quantified in aerobically growing mycobacterial cells using 2-deoxy-D-ribose assay. Furthermore, extraneous addition of hydroxyl radical in Wayne's dormancy model induced reactivation of dormant cells...
January 2018: International Journal of Mycobacteriology
Valerie S Forsyth, Chelsie E Armbruster, Sara N Smith, Ali Pirani, A Cody Springman, Matthew S Walters, Greta R Nielubowicz, Stephanie D Himpsl, Evan S Snitkin, Harry L T Mobley
Uropathogenic Escherichia coli (UPEC) strains cause most uncomplicated urinary tract infections (UTIs). These strains are a subgroup of extraintestinal pathogenic E. coli (ExPEC) strains that infect extraintestinal sites, including urinary tract, meninges, bloodstream, lungs, and surgical sites. Here, we hypothesize that UPEC isolates adapt to and grow more rapidly within the urinary tract than other E. coli isolates and survive in that niche. To date, there has not been a reliable method available to measure their growth rate in vivo Here we used two methods: segregation of nonreplicating plasmid pGTR902, and peak-to-trough ratio (PTR), a sequencing-based method that enumerates bacterial chromosomal replication forks present during cell division...
March 6, 2018: MBio
Xin Kong, Shuyao Yu, Wen Fang, Jianguo Liu, Huan Li
The impacts of ZVI on microbial community diversity in an anaerobic assay with high organic loading were investigated. The relative abundance of bacteria, archaea, and the functional methyl coenzyme-M reductase (mcrA) gene were investigated using high-throughput sequencing, and variations in their quantity were determined by qPCR. The results showed that ZVI significantly increased both the relative abundance and quantity of Methanobacteriales and Methanosarcinales during hydrogenotrophic and acetoclastic methanogenesis...
February 23, 2018: Bioresource Technology
Xiaojing Zhang, Yue Zhou, Siyu Zhao, Rongrong Zhang, Zhaoxue Peng, Hanfei Zhai, Hongzhong Zhang
In this study, the effect of Fe (II) on Anaerobic Ammonium Oxidation (ANAMMOX) process was investigated by step-wise increasing the Fe (II) in influent from 1 to 50 mg L-1 . The nitrogen removal, biofilm property and the microbial community were analyzed in each phase. Results showed that, the anaerobic ammonia-oxidizing bacteria (AAOB) bioactivity and the nitrogen removal of ANAMMOX system were slightly improved to 0.58 from the initial 0.51 kg m-3 d-1 by Fe (II) in 1-5 mg L-1 . The nitrogen removal was suppressed and could recover to the initial level during the same period under 10-20 mg L-1 Fe (II), while it did not recover to the initial level under 30 mg L-1 Fe (II) and showed no recovery performance under 50 mg L-1 Fe (II)...
February 22, 2018: Chemosphere
Stéphane L Benoit, Ashley A Holland, Michael K Johnson, Robert J Maier
Helicobacter pylori is anomalous among non-nitrogen fixing bacteria in containing an incomplete NIF system for Fe-S cluster assembly comprising two essential proteins, NifS (cysteine desulfurase) and NifU (scaffold protein). Although nifU deletion strains cannot be obtained via the conventional gene replacement, a NifU-depleted strain was constructed and shown to be more sensitive to oxidative stress compared to wild-type (WT) strains. The hp1492 gene, encoding a putative Nfu-type Fe-S cluster carrier protein, was disrupted in three different H...
March 2, 2018: Molecular Microbiology
Juliane Hoyer, Jürgen Bartel, Alejandro Gómez-Mejia, Manfred Rohde, Claudia Hirschfeld, Nathalie Heß, Thomas Sura, Sandra Maaß, Sven Hammerschmidt, Dörte Becher
Iron is an essential trace element and involved in various key metabolic pathways in bacterial lifestyle. Within the human host, iron is extremely limited. Hence, the ability of bacteria to acquire iron from the environment is critical for a successful infection. Streptococcus pneumoniae (the pneumococcus) is a human pathobiont colonizing symptomless the human respiratory tract, but can also cause various local and invasive infections. To survive and proliferate pneumococci have therefore to adapt their metabolism and virulence factor repertoire to different host compartments...
February 13, 2018: International Journal of Medical Microbiology: IJMM
Isabel M López-Lara, Joaquina Nogales, Ángel Pech-Canul, Nieves Calatrava-Morales, Lydia M Bernabéu-Roda, Paloma Durán, Virginia Cuéllar, José Olivares, Laura Alvarez, Diana Palenzuela-Bretones, Manuel Romero, Stephan Heeb, Miguel Cámara, Otto Geiger, María J Soto
Surface motility and biofilm formation are behaviours which enable bacteria to infect their hosts and are controlled by different chemical signals. In the plant symbiotic alpha-proteobacterium Sinorhizobium meliloti, the lack of long-chain fatty acyl-coenzyme A synthetase activity (FadD) leads to increased surface motility, defects in biofilm development, and impaired root colonization. In this study, analyses of lipid extracts and volatiles revealed that a fadD mutant accumulates 2-tridecanone (2-TDC), a methylketone known as a natural insecticide...
February 28, 2018: Environmental Microbiology
Lvqin He, Ke Dai, Xintian Wen, Lingqiang Ding, Sanjie Cao, Xiaobo Huang, Rui Wu, Qin Zhao, Yong Huang, Qigui Yan, Xiaoping Ma, Xinfeng Han, Yiping Wen
Haemophilus parasuis is known as a commensal organism discovered in the upper respiratory tract of swine where the pathogenic bacteria survive in various adverse environmental stress. QseC, a histidine protein kinase of the two-component regulatory systems CheY/QseC, is involved in the environmental adaptation in bacteria. To investigate the role of QseC in coping with the adverse environment stresses and survive in the host, we constructed a qseC mutant of H. parasuis serovar 13 strain (Δ qseC ), MY1902. In this study, we found that QseC was involved in stress tolerance of H...
2018: Frontiers in Microbiology
Meghan M Verstraete, Cecilia Perez-Borrajero, Kirstin L Brown, David E Heinrichs, Michael E P Murphy
Staphyloferrin B (SB) is an iron-chelating siderophore produced by Staphylococcus aureus in invasive infections. Proteins for SB biosynthesis and export are encoded by the sbnABCDEFGHI gene cluster, in which SbnI, a member of the ParB/Srx superfamily, acts as a heme-dependent transcriptional regulator of the sbn locus. However, no structural or functional information about SbnI is available. Here, a crystal structure of SbnI revealed striking structural similarity to an ADP-dependent free serine kinase, SerK, from the archaea Thermococcus kodakarensis We found that features of the active sites are conserved, and biochemical assays, and 31P NMR and HPLC analyses indicated that SbnI is also a free serine kinase but uses ATP rather than ADP as phosphate donor to generate the SB precursor O-phospho-L-serine (OPS)...
February 26, 2018: Journal of Biological Chemistry
Daisuke Hira, Ryuji Kitamura, Teruya Nakamura, Yuriko Yamagata, Kenji Furukawa, Takao Fujii
Anammox is a bacterial energy metabolic process that forms N2 gas from nitrite and ammonium ions. The enzymatic mechanisms of anammox have been gradually revealed; however, the electron transport chain in anammox bacteria remains poorly understood. In the present study, we purified and characterized two low-molecular-weight c-type cytochromes from an enriched culture of the anammox bacterium strain, KSU-1. Their genes, KSU1_B0428 and KSU1_C0855, were identified in the KSU-1 genome, and their recombinant proteins were characterized...
February 23, 2018: Journal of Molecular Biology
Xiang Li, Yong Huang, Heng-Wei Liu, Chuan Wu, Wei Bi, Yi Yuan, Xin Liu
In recent years, there have been a number of reports on the phenomenon in which ferric iron (Fe(III)) is reduced to ferrous iron [Fe(II)] in anaerobic environments, accompanied by simultaneous oxidation of ammonia to NO2 - , NO3 - , or N2. However, studies on the relevant reaction characteristics and mechanisms are rare. Recently, in research on the effect of Fe(III) on the activity of Anammox sludge, excess ammonia oxidization has also been found. Hence, in the present study, Fe(III) was used to serve as the electron acceptor instead of NO2 - , and the feasibility and characteristics of Anammox coupled to Fe(III) reduction (termed Feammox) were investigated...
February 2018: Journal of Environmental Sciences (China)
Michela Ciabocco, Patrizia Cancemi, Maria Luisa Saladino, Eugenio Caponetti, Rosa Alduina, Mario Berrettoni
This paper deals with the synthesis and characterization of iron-hexacyanocobaltate (FeHCC) and its antibacterial properties. The nanoparticles were prepared by a facile co-precipitation technique. Crystal structure, particle morphology, and elemental composition were determined using X-ray Powder Diffraction, X-ray fluorescence spectroscopy, Transmission Electron Microscopy (TEM), and Infrared Spectroscopy (IR). The antibacterial activity of the FeHCC nanoparticles was tested against Escherichia coli and Staphylococcus aureus as models for Gram-negative and Gram-positive bacteria, respectively, by bacterial counting method and microscopic visualization (TEM, FEG-SEM, and fluorescence microscopy)...
February 24, 2018: Journal of Biological Inorganic Chemistry: JBIC
Oliver Baars, François M M Morel, Xinning Zhang
Many bacteria produce siderophores to bind and take up Fe(III), an essential trace metal with extremely low solubility in oxygenated environments at circumneutral pH. The purple non-sulfur bacterium Rhodopseudomonas palustris str. CGA009 is a metabolically versatile model organism with high iron requirements that is able to grow under aerobic and anaerobic conditions. Siderophore biosynthesis has been predicted by genomic analysis, however siderophore structures were not identified. Here, we elucidate the structure of two novel siderophores from R...
February 23, 2018: Environmental Microbiology
Sunhee Ha, Bora Shin, Woojun Park
The aceA and glcB genes, encoding isocitrate lyase (ICL) and malate synthase, respectively, are not in an operon in many bacteria, including Pseudomonas aeruginosa, unlike in Escherichia coli. Here, we show that expression of aceA in P. aeruginosa is specifically upregulated under H2O2-induced oxidative stress and under iron-limiting conditions. In contrast, the addition of exogenous redox active compounds or antibiotics increases the expression of glcB. The transcriptional start sites of aceA under iron-limiting conditions and in the presence of iron were found to be identical by 5' RACE...
February 21, 2018: Microbiology
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