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Author (up) 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 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).
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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 (up) Rodríguez-Valdecantos, G.; Torres-Rojas, F.; Muñoz-Echeverría, S.; Mora-Ruiz, M.D.; Rosselló-Móra, R.; Cid-Cid, L.; Ledger, T.; González, B.
Title Aromatic compounds depurative and plant growth promotion rhizobacteria abilities of Allenrolfea vaginata (Amaranthaceae) rhizosphere microbial communities from a solar saltern hypersaline soil Type
Year 2023 Publication Frontiers In Microbiology Abbreviated Journal Front. Microbiol.
Volume 14 Issue Pages 1251602
Keywords aromatic compounds; halophiles; PGPR; rhizospheres; alterns
Abstract Introduction: This work investigates whether rhizosphere microorganisms that colonize halophyte plants thriving in saline habitats can tolerate salinity and provide beneficial effects to their hosts, protecting them from environmental stresses, such as aromatic compound (AC) pollution.Methods: To address this question, we conducted a series of experiments. First, we evaluated the effects of phenol, tyrosine, 4-hydroxybenzoic acid, and 2,4-dichlorophenoxyacetic (2,4-D) acids on the soil rhizosphere microbial community associated with the halophyte Allenrolfea vaginata. We then determined the ability of bacterial isolates from these microbial communities to utilize these ACs as carbon sources. Finally, we assessed their ability to promote plant growth under saline conditions.Results: Our study revealed that each AC had a different impact on the structure and alpha and beta diversity of the halophyte bacterial (but not archaeal) communities. Notably, 2,4-D and phenol, to a lesser degree, had the most substantial decreasing effects. The removal of ACs by the rhizosphere community varied from 15% (2,4-D) to 100% (the other three ACs), depending on the concentration. Halomonas isolates were the most abundant and diverse strains capable of degrading the ACs, with strains of Marinobacter, Alkalihalobacillus, Thalassobacillus, Oceanobacillus, and the archaea Haladaptatus also exhibiting catabolic properties. Moreover, our study found that halophile strains Halomonas sp. LV-8T and Marinobacter sp. LV-48T enhanced the growth and protection of Arabidopsis thaliana plants by 30% to 55% under salt-stress conditions.Discussion: These results suggest that moderate halophile microbial communities may protect halophytes from salinity and potential adverse effects of aromatic compounds through depurative processes.
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:001102328400001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1918
Permanent link to this record