Differentiation of microbial communities in coastal seawater before and during an Akashiwo sanguinea (Dinophyceae) bloom in the urban area of Antofagasta city (northern Chile).

Harmful algal blooms (HABs) are highly relevant for public health, the economy, the ecosystem, and biodiversity stability in southern Chile (40° to 53°S), where they occur regularly and are frequently monitored. However, HAB events and their associated microbes in northern Chile (17° to 30°S) remain unknown and difficult to track due to a lack of monitoring, particularly in urban areas. We investigated changes in microbial communities in coastal seawater before and during an Akashiwo sanguinea bloom (B) at two sampling points in Antofagasta city (23°38'39S, 70°24'39W).

Identification of bacteria in potential mutualism with toxic Alexandrium catenella in Chilean Patagonian fjords by in vitro and field monitoring.

The dinoflagellate Alexandrium catenella is a well-known paralytic shellfish toxin producer that forms harmful algal blooms, repeatedly causing damage to Chilean coastal waters. The causes and behavior of algal blooms are complex and vary across different regions. As bacterial interactions with algal species are increasingly recognized as a key factor driving algal blooms, the present study identifies several bacterial candidates potentially associated with Chilean Alexandrium catenella.

Variovorax sp. strain P1R9 applied individually or as part of bacterial consortia enhances wheat germination under salt stress conditions.

Endophytes isolated from extremophile plants are interesting microbes for improving the stress tolerance of agricultural plants. Here, we isolated and characterized endophytic bacteria showing plant growth-promoting (PGP) traits from plants in two extreme Chilean biomes (Atacama Desert and Chilean Patagonia). Forty-two isolates were characterized as both halotolerant auxin producers (2-51 mg L) and 1-aminocyclopropane-1-carboxylate (ACC)-degrading bacteria (15-28 µmol αKB mg protein h).

Pathogen profile of Baiyangdian Lake sediments using metagenomic analysis and their correlation with environmental factors.

Increasing concerns about public health and safety after covid-19 have raised pathogen studies, especially in aquatic environments. However, the extent to how different location and human activities affect geographic occurrence and distribution of pathogens in response to agricultural pollution, boat tourism disturbances and municipal wastewater inflow in a degraded lake remains unclear. Since the surrounding residents depend on the lake for their livelihood, understanding the pathogens reserved in lake sediment and the regulation possibility by environmental factors are challenges with far-reaching significance.

Endophytic bacterial communities in ungerminated and germinated seeds of commercial vegetables.

Chile is a prominent seed exporter globally, but the seed microbiome of vegetables (46% of seeds) and its role in the early stages of plant growth have remained largely unexplored. Here, we employed DNA metabarcoding analysis to investigate the composition and putative functions of endophytic bacterial communities in ungerminated and germinated seeds of the commercial vegetables Apiaceae (parsley and carrot), Asteraceae (lettuce), Brassicaceae (cabbage and broccoli), and Solanaceae (tomato). Bacterial quantification showed 10 to 10 copies of the 16S rRNA gene per gram of ungerminated and germinated seeds.

Monitoring bacterial composition and assemblage in the Gulf of Corcovado, southern Chile: Bacteria associated with harmful algae.

Harmful Algal Blooms (HABs) have caused damage to the marine environment in Isla San Pedro in the Gulf of Corcovado, Chile. While rising water temperature and artificial eutrophication are the most discussed topics as a cause, marine bacteria is a recent attractive parameter as an algal bloom driver. This study monitored algal and bacterial compositions in the water of Isla San Pedro for one year using microscopy and 16S rRNA metabarcoding analysis, along with physicochemical parameters.

An overview of plasmid transfer in the plant microbiome.

Plant microbiomes are pivotal for healthy plant physiological development. Microbes live in complex co-association with plant hosts, and interactions within these microbial communities vary with plant genotype, plant compartment, phenological stage, and soil properties, among others. Plant microbiomes also harbor a substantial and diverse pool of mobile genes encoded on plasmids.

Structure and Functional Properties of Bacterial Communities in Surface Sediments of the Recently Declared Nutrient-Saturated Lake Villarrica in Southern Chile.

Lake Villarrica, one of Chile's main freshwater water bodies, was recently declared a nutrient-saturated lake due to increased phosphorus (P) and nitrogen (N) levels. Although a decontamination plan based on environmental parameters is being established, it does not consider microbial parameters. Here, we conducted high-throughput DNA sequencing and quantitative polymerase chain reaction (qPCR) analyses to reveal the structure and functional properties of bacterial communities in surface sediments collected from sites with contrasting anthropogenic pressures in Lake Villarrica.

Metagenomics reveals biogeochemical processes carried out by sediment microbial communities in a shallow eutrophic freshwater lake.

Introduction: As the largest shallow freshwater lake in the North China Plain, Baiyangdian lake is essential for maintaining ecosystem functioning in this highly populated region. Sediments are considered to record the impacts of human activities.

Methods: The abundance, diversity and metabolic pathways of microbial communities in sediments were studied by metagenomic approach to reveal patterns and mechanism of C, N, P and S cycling under the threat of lake eutrophication.

Ecological risk assessment of glyphosate and its possible effect on bacterial community in surface sediments of a typical shallow Lake, northern China.

Glyphosate is a widely used herbicide worldwide and its prevalent presence in aquatic ecosystems poses a threat to living organisms. This study evaluated potential ecological risk of glyphosate to sediment-dwelling organisms and assessed the probable effect of glyphosate on structure and predicated function of sediment-attached bacterial communities from a large shallow lake in northern China based on 16S rRNA high-throughput sequencing. Results suggested that glyphosate showed a medium to high concentration (up to 8.

Spatiotemporal distributions and relationships of phosphorus content, phosphomonoesterase activity, and bacterial phosphomonoesterase genes in sediments from a eutrophic brackish water lake in Chile.

Phosphorus (P) cycling by microbial activity is highly relevant in the eutrophication of lakes. In this context, the contents of organic (P) and inorganic (P) phosphorus, the activity of acid (ACP) and alkaline (ALP) phosphomonoesterase (Pase), and the abundances of bacterial Pase genes (phoD, phoC, and phoX) were studied in sediments from Budi Lake, a eutrophic coastal brackish water lake in Chile. Our results showed spatiotemporal variations in P fractions, Pase activities, and Pase gene abundances.

Fate and ecological risks of antibiotics in water-sediment systems with cultivated and wild Phragmites australis in a typical Chinese shallow lake.

River carrying antibiotics from upstream posed serious threats to receiving lake, and plants might had effects on antibiotics. Therefore, samples of waters, sediments and tissues of cultivated and wild Phragmites australis were collected to analyse antibiotics fate and ecological risks (RQs) in Zaozhadian Lake. Our results revealed that the total antibiotics showed an increasing tendency in surface/pore water and P.

Airborne bacterial community associated with fine particulate matter (PM) under different air quality indices in Temuco city, southern Chile.

Temuco (Chile) is one of the most polluted cities in Chile and Latin America. Although the fine fraction of particulate matter (PM) has been extensively studied and monitored due to its negative impact on public health, its microbiological components remain unknown. We explored, the airborne bacterial community in PM under good, moderate, alert, pre-emergency and emergency indices of air quality (AQIs) established by the Chilean government.

A Standardized Procedure for Monitoring Harmful Algal Blooms in Chile by Metabarcoding Analysis.

Harmful algae blooms (HABs) monitoring has been implemented worldwide, and Chile, a country famous for its fisheries and aquaculture, has intensively used microscopic and toxin analyses for decades for this purpose. Molecular biological methods, such as high-throughput DNA sequencing and bacterial assemblage-based approaches, are just beginning to be introduced in Chilean HAB monitoring, and the procedures have not yet been standardized. Here, 16S rRNA and 18S rRNA metabarcoding analyses for monitoring Chilean HABs are introduced stepwise.

Rhizobacteria from 'flowering desert' events contribute to the mitigation of water scarcity stress during tomato seedling germination and growth.

Tomato (Solanum lycopersicum L.) is an important vegetable cultivated around the world. Under field conditions, tomato can be negatively affected by water scarcity in arid and semiarid regions.

CRISPR loci-PCR as Tool for Tracking sp. Strain B510.

-based plant and soil inoculants are widely used in agriculture. The inoculated strains are commonly tracked by both culture-dependent and culture-independent methods, which are time-consuming or expensive. In this context, clustered regularly interspaced short palindromic repeats (CRISPR) loci structure is unique in the bacterial genome, including some species.

Suitcase Lab: new, portable, and deployable equipment for rapid detection of specific harmful algae in Chilean coastal waters.

Phytoplankton blooms, including harmful algal blooms (HABs), have serious impacts on ecosystems, public health, and productivity activities. Rapid detection and monitoring of marine microalgae are important in predicting and managing HABs. We developed a toolkit, the Suitcase Lab, to detect harmful algae species in the field.

Isolation and Characterization of Cold-Tolerant Hyper-ACC-Degrading Bacteria from the Rhizosphere, Endosphere, and Phyllosphere of Antarctic Vascular Plants.

1-Aminociclopropane-1-carboxylate (ACC)-degrading bacteria having been widely studied for their use in alleviating abiotic stresses in plants. In the present study, we isolated and characterized ACC-degrading bacteria from the rhizosphere, phyllosphere, and endosphere of the Antarctic vascular plants and . One hundred and eighty of the 578 isolates (31%) were able to grow on minimal medium containing ACC, with 101 isolates (23, 37, and 41 endosphere-, phyllosphere- and rhizosphere-associated isolates, respectively) identified as being genetically unique by enterobacterial repetitive intergenic consensus (ERIC)-PCR.

Protocols for Monitoring Harmful Algal Blooms for Sustainable Aquaculture and Coastal Fisheries in Chile.

Harmful algae blooms (HABs) cause acute effects on marine ecosystems due to their production of endogenous toxins or their enormous biomass, leading to significant impacts on local economies and public health. Although HAB monitoring has been intensively performed at spatiotemporal scales in coastal areas of the world over the last decades, procedures have not yet been standardized. HAB monitoring procedures are complicated and consist of many methodologies, including physical, chemical, and biological water sample measurements.

Airborne bacterial communities of outdoor environments and their associated influencing factors.

Microbial entities (such bacteria, fungi, archaea and viruses) within outdoor aerosols have been scarcely studied compared with indoor aerosols and nonbiological components, and only during the last few decades have their studies increased. Bacteria represent an important part of the microbial abundance and diversity in a wide variety of rural and urban outdoor bioaerosols. Currently, airborne bacterial communities are mainly sampled in two aerosol size fractions (2.

Composition and predicted functions of the bacterial community in spouting pool sediments from the El Tatio Geyser field in Chile.

The El Tatio Geyser Field (ETGF), located in Northern Chile, is the main geyser field in the southern hemisphere. Despite this, details of its microbial ecology are still unknown. Here, we briefly report on  the composition and predicted functions of the bacterial community in spouting pool sediments from the ETGF as revealed by high-throughput sequencing of 16S rRNA genes.

Niche Differentiation in the Composition, Predicted Function, and Co-occurrence Networks in Bacterial Communities Associated With Antarctic Vascular Plants.

Climate change directly affecting the Antarctic Peninsula has been reported to induce the successful colonization of ice-free lands by two Antarctic vascular plants ( and ). While studies have revealed the importance of microbiota for plant growth and stress tolerance in temperate climates, the role that plant-associated microbes play in the colonization of ice-free lands remains unknown. Consequently, we used high-throughput DNA sequence analyses to explore the composition, predicted functions, and interactive networks of plant-associated microbial communities among the rhizosphere, endosphere, and phyllosphere niches of and .