Publications by authors named "Amanda G Bendia"

The district of Perus, located in the city of São Paulo, Brazil, is renowned for its weathered granitic-pegmatitic masses, which harbor a significant number of uraniferous minerals that contribute to ionizing radiation levels up to 20 times higher than the background levels. In this study, aseptically collected mineral samples from the area were utilized to isolate 15 microorganisms, which were subjected to pre-screening tests involving UV-C and UV-B radiation. The microorganisms that exhibited the highest resistance to ultraviolet (UV) radiation were selected for the construction of survival curves for UV-C, broad-band UV-B, and solar simulation resistance testing.

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Microorganisms in Antarctica are recognized for having crucial roles in ecosystems functioning and biogeochemical cycles. To explore the diversity and composition of microbial communities through different terrestrial and marine Antarctic habitats, we analyze 16S rRNA sequence datasets from fumarole and marine sediments, soil, snow and seawater environments. We obtained measures of alpha- and beta-diversities, as well as we have identified the core microbiome and the indicator microbial taxa of a particular habitat.

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Continental slopes can play a significant contribution to marine productivity and carbon cycling. These regions can harbour distinct geological features, such as salt diapirs and pockmarks, in which their depressions may serve as natural sediment traps where different compounds can accumulate. We investigated the prokaryotic communities in surface (0-2 cm) and subsurface (18-20 or 22-24 cm) sediments from a salt diapir and pockmark field in Santos Basin, Southwest Atlantic Ocean.

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Antarctic active volcanoes can disperse pyroclastic minerals at long distances, transporting nutrients and microorganisms to the surrounding glacial environment. The sedimented volcanic materials - called tephras - may interact with glacier ice and produce a unique environment for microbial life. This study aimed to describe the microbial community structure of an Antarctic glacier ice with tephra layers in terms of its taxonomic and functional diversity.

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Microbial communities have been explored in various terrestrial subsurface ecosystems, showing metabolic potentials that could generate noteworthy morphological and molecular biosignatures. Recent advancements in bioinformatic tools have allowed for descriptions of novel and yet-to-be cultivated microbial lineages in different ecosystems due to the genome reconstruction approach from metagenomic data. Using shotgun metagenomic data, we obtained metagenome-assembled genomes related to cultivated and yet-to-be cultivated prokaryotic lineages from a silica and iron-rich cave (Monte Cristo) in Minas Gerais State, Brazil.

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Deep-sea carbonate mounds can harbor a wide variety of heterotrophic and chemosynthetic microbial communities, providing biodiversity hotspots among the deep-sea benthic ecosystems. This study examined the bacterial and archaeal diversity and community structure in the water column and sediments associated with a recently described giant carbonate mound named Alpha Crucis Carbonate Ridge (ACCR), located in the Southwestern Atlantic Ocean. Because of the acoustic evidence of gas chimneys from a previous study, we further evaluated the chemosynthetic primary production through in situ-simulated dark carbon fixation rates.

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Active volcanoes in Antarctica have remarkable temperature and geochemical gradients that could select for a wide variety of microbial adaptive mechanisms and metabolic pathways. Deception Island is a stratovolcano flooded by the sea, resulting in contrasting ecosystems such as permanent glaciers and active fumaroles, which creates steep gradients that have been shown to affect microbial diversity. In this study, we used shotgun metagenomics and metagenome-assembled genomes to explore the metabolic potentials and survival strategies of microbial communities along an extreme temperature gradient in fumarole and glacier sediments on Deception Island.

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Marine plastic pollution is a global concern because of continuous release into the oceans over the last several decades. Although recent studies have made efforts to characterize the so-called plastisphere, or microbial community inhabiting plastic substrates, it is not clear whether the plastisphere is defined as a core community or as a random attachment of microbial cells. Likewise, little is known about the influence of the deep-sea environment on the plastisphere.

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Seamounts are often covered with Fe and Mn oxides, known as ferromanganese (Fe-Mn) crusts. Future mining of these crusts is predicted to have significant effects on biodiversity in mined areas. Although microorganisms have been reported on Fe-Mn crusts, little is known about the role of crusts in shaping microbial communities.

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Here we investigated the diversity of bacterial communities from deep-sea surface sediments under influence of asphalt seeps at the Sao Paulo Plateau using next-generation sequencing method. Sampling was performed at North São Paulo Plateau using the human occupied vehicle Shinkai 6500 and her support vessel Yokosuka. The microbial diversity was studied at two surficial sediment layers (0-1 and 1-4 cm) of five samples collected in cores in water depths ranging from 2456 to 2728 m.

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Polar volcanoes harbor unique conditions of extreme temperature gradients capable of selecting different types of extremophiles. Deception Island is a marine stratovolcano located at Maritime Antarctica that is notable for its pronounced temperature gradients over very short distances, reaching values up to 100 °C in the fumaroles, and subzero temperatures next to the glaciers. Due to these characteristics, Deception can be considered an interesting analogue of extraterrestrial environments.

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Active volcanoes in Antarctica contrast with their predominantly cold surroundings, resulting in environmental conditions capable of selecting for versatile and extremely diverse microbial communities. This is especially true on Deception Island, where geothermal, marine, and polar environments combine to create an extraordinary range of environmental conditions. Our main goal in this study was to understand how microbial community structure is shaped by gradients of temperature, salinity, and geochemistry in polar marine volcanoes.

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Uncultured microorganisms comprise most of the microbial diversity existing on our planet. Despite advances in environmental sequencing and single-cell genomics, in-depth studies about bacterial metabolism and screening of novel bioproducts can only be assessed by culturing microbes in the laboratory. Here we report uncultured, or recalcitrant, microorganisms from an Antarctic soil sample, using relatively simple methods: oligotrophic media, extended incubation periods, observation under stereo microscopy, and selection of slow-growing bacteria.

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Astrobiology is a transdisciplinary field with extraordinary potential for the scientific community. As such, it is important to educate the community at large about the growing importance of this field to increase awareness and scientific content learning and expose potential future scientists. To this end, we propose the creation of a traveling museum exhibit that focuses exclusively on astrobiology and utilizes modern museum exhibit technology and design.

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