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Author Diaz-Rullo, J.; Rodriguez-Valdecantos, G.; Torres-Rojas, F.; Cid, L.; Vargas, I.T.; Gonzalez, B.; Gonzalez-Pastor, J.E.
Title Mining for Perchlorate Resistance Genes in Microorganisms From Sediments of a Hypersaline Pond in Atacama Desert, Chile Type
Year 2021 Publication (up) Frontiers In Microbiology Abbreviated Journal Front. Microbiol.
Volume 12 Issue Pages 723874
Keywords perchlorate-resistance; oxidative stress; tRNA modification; DNA repair; protein damage; hypersaline environments; Atacama Desert; Mars
Abstract Perchlorate is an oxidative pollutant toxic to most of terrestrial life by promoting denaturation of macromolecules, oxidative stress, and DNA damage. However, several microorganisms, especially hyperhalophiles, are able to tolerate high levels of this compound. Furthermore, relatively high quantities of perchlorate salts were detected on the Martian surface, and due to its strong hygroscopicity and its ability to substantially decrease the freezing point of water, perchlorate is thought to increase the availability of liquid brine water in hyper-arid and cold environments, such as the Martian regolith. Therefore, perchlorate has been proposed as a compound worth studying to better understanding the habitability of the Martian surface. In the present work, to study the molecular mechanisms of perchlorate resistance, a functional metagenomic approach was used, and for that, a small-insert library was constructed with DNA isolated from microorganisms exposed to perchlorate in sediments of a hypersaline pond in the Atacama Desert, Chile (Salar de Maricunga), one of the regions with the highest levels of perchlorate on Earth. The metagenomic library was hosted in Escherichia coli DH10B strain and exposed to sodium perchlorate. This technique allowed the identification of nine perchlorate-resistant clones and their environmental DNA fragments were sequenced. A total of seventeen ORFs were predicted, individually cloned, and nine of them increased perchlorate resistance when expressed in E. coli DH10B cells. These genes encoded hypothetical conserved proteins of unknown functions and proteins similar to other not previously reported to be involved in perchlorate resistance that were related to different cellular processes such as RNA processing, tRNA modification, DNA protection and repair, metabolism, and protein degradation. Furthermore, these genes also conferred resistance to UV-radiation, 4-nitroquinoline-N-oxide (4-NQO) and/or hydrogen peroxide (H2O2), other stress conditions that induce oxidative stress, and damage in proteins and nucleic acids. Therefore, the novel genes identified will help us to better understand the molecular strategies of microorganisms to survive in the presence of perchlorate and may be used in Mars exploration for creating perchlorate-resistance strains interesting for developing Bioregenerative Life Support Systems (BLSS) based on in situ resource utilization (ISRU).
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1664-302X ISBN Medium
Area Expedition Conference
Notes WOS:000681631900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1456
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Author Pavissich, J.P.; Vargas, I.T.; Gonzalez, B.; Pasten, P.A.; Pizarro, G.E.
Title Culture dependent and independent analyses of bacterial communities involved in copper plumbing corrosion Type
Year 2010 Publication (up) Journal Of Applied Microbiology Abbreviated Journal J. Appl. Microbiol.
Volume 109 Issue 3 Pages 771-782
Keywords bacterial community; biofilm; copper plumbing; microbially influenced corrosion; water quality
Abstract Aims: This study used culture-dependent and culture-independent approaches to characterize bacterial communities in copper plumbing corrosion and to assess biofilm formation and copper resistance of heterotrophic bacteria isolated from copper pipes. Methods and Results: Water and copper pipes were collected from a cold-water household distribution system affected by 'blue water' corrosion and presenting biofilm formation. Corrosion-promoting ageing experiments were performed with conditioned unused copper pipes filled with unfiltered and filtered sampled water as nonsterile and sterile treatments, respectively. During 8 weeks, stagnant water within the pipes was replaced with aerated fresh water every 2 or 3 days. Total copper and pH were determined in sampled water, and copper pipe coupons were cut for microscopic analyses. Biofilms were extracted from field and laboratory pipes, and total DNA was isolated. Bacterial communities' composition was analysed by terminal restriction fragment length polymorphism (T-RFLP) and clonal libraries of 16S rRNA genes. Heterotrophic bacterial isolates were obtained from water and biofilm extracts and characterized in terms of biofilm formation capacity and copper minimum inhibitory concentration. The results indicated that copper concentration in stagnant water from nonsterile treatments was much higher than in sterile treatments and corrosion by-products structure in coupon surfaces was different. Multivariate analysis of T-RFLP profiles and clone sequencing showed significant dissimilarity between field and laboratory biofilm communities, and a low richness and the dominant presence of Gamma- and Betaproteobacteria in both cases. Several bacterial isolates formed biofilm and tolerated high copper concentrations. Conclusions: The study demonstrates microbially influenced corrosion (MIC) in copper plumbing. Gamma- and Betaproteobacteria dominated the corroded copper piping bacterial community, whose ability to form biofilms may be important for bacterial corrosion promotion and survival in MIC events. Significance and Impact of the Study: The characterization of micro-organisms that influence copper plumbing corrosion has significant implications for distribution system management and copper corrosion control.
Address [Pavissich, J. P.; Vargas, I. T.; Pasten, P. A.; Pizarro, G. E.] Pontificia Univ Catolica Chile, Dept Ingn Hidraul & Ambiental, Escuela Ingn, Santiago 6904411, Chile, Email: gpizarro@ing.puc.cl
Corporate Author Thesis
Publisher Wiley-Blackwell Publishing, Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1364-5072 ISBN Medium
Area Expedition Conference
Notes WOS:000280979700004 Approved
Call Number UAI @ eduardo.moreno @ Serial 93
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Author Vargas, I.T.; Fischer, D.A.; Alsina, M.A.; Pavissich, J.P.; Pasten, P.A.; Pizarro, G.E.
Title Copper Corrosion and Biocorrosion Events in Premise Plumbing Type
Year 2017 Publication (up) Materials Abbreviated Journal Materials
Volume 10 Issue 9 Pages 30 pp
Keywords copper; corrosion; biocorrosion; drinking water; premise plumbing; MIC
Abstract Corrosion of copper pipes may release high amounts of copper into the water, exceeding the maximum concentration of copper for drinking water standards. Typically, the events with the highest release of copper into drinking water are related to the presence of biofilms. This article reviews this phenomenon, focusing on copper ingestion and its health impacts, the physicochemical mechanisms and the microbial involvement on copper release, the techniques used to describe and understand this phenomenon, and the hydrodynamic effects. A conceptual model is proposed and the mathematical models are reviewed.
Address [Vargas, Ignacio T.; Fischer, Diego A.; Alsina, Marco A.; Pasten, Pablo A.; Pizarro, Gonzalo E.] Pontificia Univ Catolica Chile, Dept Ingn Hidraul & Ambiental, Santiago 7820436, Chile, Email: itvargas@ing.puc.cl;
Corporate Author Thesis
Publisher Mdpi Ag Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1996-1944 ISBN Medium
Area Expedition Conference
Notes WOS:000411506700120 Approved
Call Number UAI @ eduardo.moreno @ Serial 806
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