The ISME Journal Archives - Astrobiology

Location of sediment sampling and pictures of resurrected species S. marinoi. (A) Map of the Baltic Sea (northern Europe) with the location of sediment core sampling (EMB262/6; 240 m water depth) in the eastern Gotland Basin (triangle). Additional sampling points of stratigraphy reference cores (points): M86-1a/36 [35], MSM62–60 [36], and P435-2-1 [34]. (B) Pictures of different Lugol-stained strains of S. marinoi. Strain SM_EGB_382_11 from 6871 ± 140 years of dormancy, SM_EGB_1_5 from 3 ± 2 years of dormancy, SM_EGB_107_1 from 1131 ± 110 years of dormancy, SM_EGB_20_4 from 58 ± 5 years of dormancy, and SM_EGB_232_2 from 3411 ± 120 years of dormancy. Scale bars = 20 μm. -- The ISME Journal

Biophysics, Biosignatures & Paleobiology, Habitable Zones, Microbiology & Virology, Sample Return, Status Report, Water/Hycean Worlds & Oceanography

Resurrection Of A Diatom After 7,000 Years From Anoxic Baltic Sea Sediment

by Keith CowingApril 1, 2025April 1, 2025

Dormancy is a widespread key life history trait observed across the tree of life. Many plankton species form dormant cell stages that accumulate in aquatic sediments and, under anoxic conditions, […]

Location of sediment sampling and pictures of resurrected species S. marinoi. (A) Map of the Baltic Sea (northern Europe) with the location of sediment core sampling (EMB262/6; 240 m water depth) in the eastern Gotland Basin (triangle). Additional sampling points of stratigraphy reference cores (points): M86-1a/36 [35], MSM62–60 [36], and P435-2-1 [34]. (B) Pictures of different Lugol-stained strains of S. marinoi. Strain SM_EGB_382_11 from 6871 ± 140 years of dormancy, SM_EGB_1_5 from 3 ± 2 years of dormancy, SM_EGB_107_1 from 1131 ± 110 years of dormancy, SM_EGB_20_4 from 58 ± 5 years of dormancy, and SM_EGB_232_2 from 3411 ± 120 years of dormancy. Scale bars = 20 μm. -- The ISME Journal

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Interstellar, Status Report

The Edge-on Disk Tau042021: Icy Grains At High Altitudes And A Wind Containing Astronomical PAHs

by Keith CowingApril 1, 2025April 1, 2025

Spectra of the nearly edge-on protoplanetary disks observed with the JWST have shown ice absorption bands of varying optical depths and peculiar profiles, challenging radiative transfer modelling and our understanding […]

Schematic of a terrestrial subsurface environment. The top layer of the subsurface is generally unsaturated, with saturated layers below. Most aquifers exist in the saturated zone, within the top 100 m from the subsurface. The saturated zone consists of aquifers in permeable rock, loose material, or fractured rock. Outside of aquifers, rock fractures within the saturated zone are often water-filled. As depth increases, so do the temperature and pressure, whereas microbial diversity and abundance are highest closer to the surface. Organic carbon, water, and oxygen become increasingly unavailable with depth, whereas H2, CO2, and CH4 gases are abundant in the deep subsurface. -- ISME Journal

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Status Report

Microbial Ecology Of The Deep Terrestrial Subsurface

by Keith CowingMarch 25, 2025March 25, 2025

The terrestrial subsurface hosts microbial communities that, collectively, are predicted to comprise as many microbial cells as global surface soils.

Earth's atmosphere as seen from the International Space Station -- NASA

Atmospheres, Climate, Weather, Biophysics, Gaia - Planetary Perspectives, Microbiology & Virology, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

Earth’s Atmosphere: A Transport Medium Or An Active Microbial Ecosystem?

by Keith CowingJune 28, 2024June 28, 2024

The atmosphere may be Earth’s largest microbial ecosystem. It is connected to all of Earth’s surface ecosystems and plays an important role in microbial dispersal on local to global scales. […]

A The scanning electron micrograph and (B, C) transmission electron micrographs of MTB. White arrows indicate magnetosome chains, and white triangles indicate granules. D Terrestrial extremotolerant MTB and implications for ancient Mars. MTB are found to be able to resist various hostile settings, such as irradiation, hypomagnetic exposure, microgravity, metal stress, hypersalinity, acidic/hyperalkaline pH, and freezing/moderately hyperthermal temperatures. MTB emerged early in Earth’s history. Since ancient Mars was also characterized by many MTB-favorable aquatic/sediment oxic-anoxic conditions and a global magnetic field, it is proposed that Mars may have harbored MTB-like life in the past. -- The ISME Journal

Astrochemistry, Astrogeology, Mars, Meteorites & Asteroids, Status Report

Renaissance For Magnetotactic Bacteria In Astrobiology

by Keith CowingFebruary 8, 2024February 8, 2024

Capable of forming magnetofossils similar to some magnetite nanocrystals observed in the Martian meteorite ALH84001, magnetotactic bacteria (MTB) once occupied a special position in the field of astrobiology during the […]