Examinando por Autor "Whyte, Lyle"

Mostrando 1 - 3 de 3

Acceso Abierto
A Multiplex Immunosensor for Detecting Perchlorate-Reducing Bacteria for Environmental Monitoring and Planetary Exploration
(Extreme Microbiology, 2020-12-16) Gallardo Carreño, Ignacio; Moreno Paz, M.; Aguirre, Jacobo; Blanco, Yolanda; Alonso Pintado, Eduardo; Raymond Bouchard, Isabelle; Maggiori, Catherine; Rivas, Luis A.; Engelbrektson, Anna; Whyte, Lyle; Parro García, V.; Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); Ministerio de Ciencia e Innovación (MICINN); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Centros de Excelencia Severo Ochoa, CENTRO NACIONAL DE BIOTECNOLOGIA (CNB), SEV-2017-0712
Perchlorate anions are produced by chemical industries and are important contaminants in certain natural ecosystems. Perchlorate also occurs in some natural and uncontaminated environments such as the Atacama Desert, the high Arctic or the Antarctic Dry Valleys, and is especially abundant on the surface of Mars. As some bacterial strains are capable of using perchlorate as an electron acceptor under anaerobic conditions, their detection is relevant for environmental monitoring on Earth as well as for the search for life on Mars. We have developed an antibody microarray with 20 polyclonal antibodies to detect perchlorate-reducing bacteria (PRB) strains and two crucial and highly conserved enzymes involved in perchlorate respiration: perchlorate reductase and chlorite dismutase. We determined the cross-reactivity, the working concentration, and the limit of detection of each antibody individually and in a multiplex format by Fluorescent Sandwich Microarray Immunoassay. Although most of them exhibited relatively high sensitivity and specificity, we applied a deconvolution method based on graph theory to discriminate between specific signals and cross-reactions from related microorganisms. We validated the system by analyzing multiple bacterial isolates, crude extracts from contaminated reactors and salt-rich natural samples from the high Arctic. The PRB detecting chip (PRBCHIP) allowed us to detect and classify environmental isolates as well as to detect similar strains by using crude extracts obtained from 0.5 g even from soils with low organic-matter levels (<103 cells/g of soil). Our results demonstrated that PRBCHIP is a valuable tool for sensitive and reliable detection of perchlorate-reducing bacteria for research purposes, environmental monitoring and planetary exploration.
Acceso Abierto
Geomicrobiological Heterogeneity of Lithic Habitats in the Extreme Environment of Antarctic Nunataks: A Potential Early Mars Analog
(Extreme Microbiology, 2021-07-02) Fernández Martínez, M. A.; García Villadangos, M.; Moreno Paz, M.; Gangloff, V.; Carrizo, D.; Blanco, Y.; González, Y.; González, S.; Sánchez García, L.; Prieto Ballesteros, O.; Altshuler, I.; Whyte, Lyle; Parro García, V.; Fairén, Alberto G.; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Comunidad de Madrid; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Nunataks are permanent ice-free rocky peaks that project above ice caps in polar regions, thus being exposed to extreme climatic conditions throughout the year. They undergo extremely low temperatures and scarcity of liquid water in winter, while receiving high incident and reflected (albedo) UVA-B radiation in summer. Here, we investigate the geomicrobiology of the permanently exposed lithic substrates of nunataks from Livingston Island (South Shetlands, Antarctic Peninsula), with focus on prokaryotic community structure and their main metabolic traits. Contrarily to first hypothesis, an extensive sampling based on different gradients and multianalytical approaches demonstrated significant differences for most geomicrobiological parameters between the bedrock, soil, and loose rock substrates, which overlapped any other regional variation. Brevibacillus genus dominated on bedrock and soil substrates, while loose rocks contained a diverse microbial community, including Actinobacteria, Alphaproteobacteria and abundant Cyanobacteria inhabiting the milder and diverse microhabitats within. Archaea, a domain never described before in similar Antarctic environments, were also consistently found in the three substrates, but being more abundant and potentially more active in soils. Stable isotopic ratios of total carbon (δ 13C) and nitrogen (δ 15N), soluble anions concentrations, and the detection of proteins involved in key metabolisms via the Life Detector Chip (LDChip), suggest that microbial primary production has a pivotal role in nutrient cycling at these exposed areas with limited deposition of nutrients. Detection of stress-resistance proteins, such as molecular chaperons, suggests microbial molecular adaptation mechanisms to cope with these harsh conditions. Since early Mars may have encompassed analogous environmental conditions as the ones found in these Antarctic nunataks, our study also contributes to the understanding of the metabolic features and biomarker profiles of a potential Martian microbiota, as well as the use of LDChip in future life detection missions.
Restringido
The Limits, Capabilities, and Potential for Life Detection with MinION Sequencing in a Paleochannel Mars Analog
(Mary Ann Liebert Publishers, 2020-03-02) Maggiori, Catherine; Stromberg, J.; Blanco, Y.; Goordial, J.; Cloutis, E.; García Villadangos, M.; Parro García, V.; Whyte, Lyle; Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737; Ministerio de Economía y Competitividad (MINECO)
No instrument capable of direct life detection has been included on a mission payload to Mars since NASA's Viking missions in the 1970s. This prevents us from discovering whether life is or ever was present on Mars. DNA is an ideal target biosignature since it is unambiguous, nonspecific, and readily detectable with nanopore sequencing. Here, we present a proof-of-concept utilization of the Oxford Nanopore Technologies (ONT) MinION sequencer for direct life detection and show how it can complement results from established space mission instruments. We used nanopore sequencing data from the MinION to detect and characterize the microbial life in a set of paleochannels near Hanksville, UT, with supporting data from X-ray diffraction, reflectance spectroscopy, Raman spectroscopy, and Life Detector Chip (LDChip) microarray immunoassay analyses. These paleochannels are analogs to martian sinuous ridges. The MinION-generated metagenomes reveal a rich microbial community dominated by bacteria and containing radioresistant, psychrophilic, and halophilic taxa. With spectral data and LDChip immunoassays, these metagenomes were linked to the surrounding Mars analog environment and potential metabolisms (e.g., methane production and perchlorate reduction). This shows a high degree of synergy between these techniques for detecting and characterizing biosignatures. We also resolved a prospective lower limit of ∼0.001 ng of DNA required for successful sequencing. This work represents the first determination of the MinION's DNA detection limits beyond ONT recommendations and the first whole metagenome analysis of a sinuous ridge analog.