Examinando por Autor "Maggiori, Catherine"

Mostrando 1 - 2 de 2

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.
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.