Secondary metabolites with antimicrobial activity produced by thermophilic bacteria from a high-altitude hydrothermal system.

Thermophilic microorganisms possess several adaptations to thrive in high temperature, which is reflected as biosynthesis of proteins and thermostable molecules, isolation and culture represent a great methodological challenge, therefore High throughput sequencing enables screening of the whole bacterial genome for functional potential, providing rapid and cost-effective information to guide targeted cultures for the identification and characterization of novel natural products. In this study, we isolated two thermophilic bacterial strains corresponding to LB7 and LB8, from the microbial mats in the Atacama Desert. By combining genome mining, targeted cultures and biochemical characterization, we aimed to identify their capacity to synthesize bioactive compounds with antimicrobial properties.

Rhizospheric bacteria from the Atacama Desert hyper-arid core: cultured community dynamics and plant growth promotion.

The Atacama Desert is the oldest and driest desert on Earth, encompassing great temperature variations, high ultraviolet radiation, drought, and high salinity, making it ideal for studying the limits of life and resistance strategies. It is also known for harboring a great biodiversity of adapted life forms. While desertification is increasing as a result of climate change and human activities, it is necessary to optimize soil and water usage, where stress-resistant crops are possible solutions.

Characterization of biofilm formation by strains in response to arsenic exposure.

In this work, we characterized the composition, structure, and functional potential for biofilm formation of strains isolated from the Salar de Huasco in Chile in the presence of arsenic, an abundant metalloid in the Salar that exists in different oxidation states. Our results showed that the strains tested exhibit a significant capacity to form biofilms when exposed to arsenic, which would contribute to their resistance to the metalloid. The results highlight the importance of biofilm formation and the presence of specific resistance mechanisms in the ability of microorganisms to survive and thrive under adverse conditions.

Exploring the Influence of Small-Scale Geographical and Seasonal Variations Over the Microbial Diversity in a Poly-extreme Athalosaline Wetland.

Microorganisms are the most diverse life form on the planet and are critical for maintaining the geochemical cycles, especially in extreme environments. Bacterial communities are dynamic and respond directly to changes in abiotic conditions; among these communities, poly-extremophiles are particularly sensitive to perturbations due to their high specialization. Salar de Huasco is a high-altitude wetland located on the Chilean Altiplano exhibiting several conditions considered extreme for life, including negative water balance, extreme variations in temperature and pH values, high UV radiation, and the presence of various toxic metal(oids).

Mobile genetic elements drive the multidrug resistance and spread of serotypes along a poultry meat production line.

The presence of mobile genetic elements in isolated from a chicken farm constitutes a potential risk for the appearance of emerging bacteria present in the food industry. These elements contribute to increased pathogenicity and antimicrobial resistance through genes that are related to the formation of biofilms and resistance genes contained in plasmids, integrons, and transposons. One hundred and thirty-three isolates from different stages of the production line, such as feed manufacturing, hatchery, broiler farm, poultry farm, and slaughterhouse, were identified, serotyped and sequenced.

Continuous bioreactors enable high-level bioremediation of diesel-contaminated seawater at low and mesophilic temperatures using Antarctic bacterial consortia: Pollutant analysis and microbial community composition.

In 2020, more than 21,000 tons of diesel oil were released accidently into the environment with most of it contaminating water bodies. There is an urgent need for sustainable technologies to clean up rivers and oceans to protect wildlife and human health. One solution is harnessing the power of bacterial consortia; however isolated microbes from different environments have shown low diesel bioremediation rates in seawater thus far.

Biochemical, genomic and structural characteristics of the Acr3 pump in strains isolated from arsenic-rich Salar de Huasco sediments.

Arsenic is a highly toxic metalloid of major concern for public safety. However, microorganisms have several resistance mechanisms, particularly the expression of arsenic pumps is a critical component for bacterial ability to expel it and decrease intracellular toxicity. In this study, we aimed to characterize the biochemical, structural, and genomic characteristics of the Acr3 pump among a group of strains isolated from different sites of the arsenic-rich Salar de Huasco (SH) ecosystem.

Genetic Characterization of Infantis with Multiple Drug Resistance Profiles Isolated from a Poultry-Farm in Chile.

comprises over 2500 serotypes and foodborne contamination associated with this pathogen remains an important health concern worldwide. During the last decade, a shift in serotype prevalence has occurred as traditionally less prevalent serotypes are increasing in frequency of infections, especially those related to poultry meat contamination. Infantis is one of the major emerging serotypes, and these strains commonly display antimicrobial resistance and can persist despite cleaning protocols.

Living to the High Extreme: Unraveling the Composition, Structure, and Functional Insights of Bacterial Communities Thriving in the Arsenic-Rich Salar de Huasco Altiplanic Ecosystem.

Microbial communities inhabiting extreme environments such as Salar de Huasco (SH) in northern Chile are adapted to thrive while exposed to several abiotic pressures and the presence of toxic elements such as arsenic (As). Hence, we aimed to uncover the role of As in shaping bacterial composition, structure, and functional potential in five different sites in this altiplanic wetland using a shotgun metagenomic approach. The sites exhibit wide gradients of As (9 to 321 mg/kg), and our results showed highly diverse communities and a clear dominance exerted by the and phyla.

Genomics Insights into sp. CG01: An Antarctic Cadmium-Resistant Strain Capable of Biosynthesizing CdS Nanoparticles Using Methionine as S-Source.

Here, we present the draft genome sequence of sp. GC01, a cadmium-resistant Antarctic bacterium capable of biosynthesizing CdS fluorescent nanoparticles (quantum dots, QDs) employing a unique mechanism involving the production of methanethiol (MeSH) from methionine (Met). To explore the molecular/metabolic components involved in QDs biosynthesis, we conducted a comparative genomic analysis, searching for the genes related to cadmium resistance and sulfur metabolic pathways.

Genomic Variation and Arsenic Tolerance Emerged as Niche Specific Adaptations by Different Strains Isolated From the Extreme Salar de Huasco Environment in Chilean - Altiplano.

Polyextremophilic bacteria can thrive in environments with multiple stressors such as the Salar de Huasco (SH). Microbial communities in SH are exposed to low atmospheric pressure, high UV radiation, wide temperature ranges, salinity gradient and the presence of toxic compounds such as arsenic (As). In this work we focus on arsenic stress as one of the main adverse factors in SH and bacteria that belong to the genus due to their plasticity and ubiquity.

Determinants of Copper Resistance in ACH Isolated from the Chilean Altiplano.

The use of microorganisms in mining processes is a technology widely employed around the world. Leaching bacteria are characterized by having resistance mechanisms for several metals found in their acidic environments, some of which have been partially described in the genus (mainly on species). However, the response to copper has not been studied in the psychrotolerant strains.

The Transcription Factor ArcA Modulates 's Metabolism in Response to Neutrophil Hypochlorous Acid-Mediated Stress.

Typhimurium, a bacterial pathogen with high metabolic plasticity, can adapt to different environmental conditions; these traits enhance its virulence by enabling bacterial survival. Neutrophils play important roles in the innate immune response, including the production of microbicidal reactive oxygen species (ROS). In addition, the myeloperoxidase in neutrophils catalyzes the formation of hypochlorous acid (HOCl), a highly toxic molecule that reacts with essential biomolecules, causing oxidative damage including lipid peroxidation and protein carbonylation.

Arsenic Response of Three Altiplanic Strains With Different Tolerance Levels Against the Metalloid Species: A Proteomics Study.

is a polyextremophile bacterial genus with a physiology that allows it to develop in different adverse environments. The Salar de Huasco is one of these environments due to its altitude, atmospheric pressure, solar radiation, temperature variations, pH, salinity, and the presence of toxic compounds such as arsenic. However, the physiological and/or molecular mechanisms that enable them to prosper in these environments have not yet been described.

Correction: The ArcAB two-component regulatory system promotes resistance to reactive oxygen species and systemic infection by Salmonella Typhimurium.

[This corrects the article DOI: 10.1371/journal.pone.

Characterization and Salt Response in Recurrent Halotolerant sp. SH31 Isolated From Sediments of Salar de Huasco, Chilean Altiplano.

Poly-extremophiles microorganisms have the capacity to inhabit hostile environments and can survive several adverse conditions that include as variations in temperature, pH, and salinity, high levels UV light and atmospheric pressure, and even the presence of toxic compounds and the formation of reactive oxygen species (ROS). A halotolerant strain was isolated from Salar de Huasco (Chilean Altiplano), a well-known shallow lake area with variable salinity levels, little human intervention, and extreme environmental conditions, which makes it ideal for the study of resistant mechanisms and the evolution of adaptations. This bacterial genus has not been extensively studied, although its cosmopolitan location indicates that it has high levels of plasticity and adaptive capacity.

The ArcAB two-component regulatory system promotes resistance to reactive oxygen species and systemic infection by Salmonella Typhimurium.

Salmonella enterica Serovar Typhimurium (S. Typhimurium) is an intracellular bacterium that overcomes host immune system barriers for successful infection. The bacterium colonizes the proximal small intestine, penetrates the epithelial layer, and is engulfed by macrophages and neutrophils.

The transcription factor SlyA from Salmonella Typhimurium regulates genes in response to hydrogen peroxide and sodium hypochlorite.

Salmonella Typhimurium is an intracellular pathogen that is capable of generating systemic fever in a murine model. Over the course of the infection, Salmonella faces different kinds of stressors, including harmful reactive oxygen species (ROS). Various defence mechanisms enable Salmonella to successfully complete the infective process in the presence of such stressors.

Comparative Genomics Analysis of a New Strain from Salar de Huasco Reveals a Repertoire of Stress-Related Genes and Arsenic Resistance.

The Atacama Desert hosts diverse ecosystems including salt flats and shallow Andean lakes. Several heavy metals are found in the Atacama Desert, and microorganisms growing in this environment show varying levels of resistance/tolerance to copper, tellurium, and arsenic, among others. Herein, we report the genome sequence and comparative genomic analysis of a new strain, sp.