Thermophilic Magnetotactic Bacteria from Mickey Hot Springs, an Arsenic-Rich Hydrothermal System in Oregon

Abstract

Magnetotactic bacteria (MTB) thrive in aquatic sediments all over the world, but their complete role(s) in their geobiological habit as well as their significance in the fossil record remains unresolved. We were able to collect, enrich, and purify MTB from Mickey Hot Springs, a unique arsenic-rich hot spring system located in the Alvord Desert of southeastern Oregon. Populations of MTB were present in water and surface sediment samples in a geothermal spring at temperature 47 °C, pH of 8.0, and 0.96 mg/L arsenic. Using 16S rDNA analysis, the organism was found to belong to the phylum Nitrospirae. Cells had rod to vibrioid morphology, a single flagellum and single magnetosome chain as determined by scanning transmission electron microscopy (STEM). The magnetosomes contained bullet-shaped crystals of magnetite (Fe3O4) approximately 84 nm long and 39 nm wide. This is the first instance of MTB collected from an arsenic-rich, moderately thermophilic environment. The discovery of MTB at this site extends the limits of habitats for these bacteria and provides a proxy for the search for magnetofossils in the rock record.

Microbial diversity and abundance in the hot springs on the west coast of Saudi Arabia as a potential source of novel industrial products

“…Three locations with hot springs on the west coast of Saudi Arabia were investigated to detect microbial diversity in the soil. To understand to diversity of the microorganisms in each location physical and chemical analysis of some soil parameters were detected and the results agreed with several studies (Hamilton & Having 2022;Mathan Kumar et al 2022;Oestreicher et al 2022;Yuan et al 2022). Microorganism populations in hot springs may be rarely identified because of the harsh conditions where they occur or because culture-dependent identification methods can only identify a small fraction of their whole communities (Rashad & Abdel-Azeem 2017;Medhavi et al 2018;Fachrial et al, 2020).…”

Renaissance for magnetotactic bacteria in astrobiology

“… Ecological niche or experimental approach Strain Stress tolerance Relevant mechanisms References Brackish desert spring in Death Valley, USA; Mono Lake, Soda Spring, and Armagosa Valley pond in California, USA Desulfamplus magnetovallimortis strain BW-1, Deltaproteobacteria strains ML-1, ZZ-1, and AV-1 Hypersaline environment (10–90 g L −1 ) Chemoorganoheterotrophic, sodium chloride-dependent, sulfate reduction [ 36 , 38 , 39 ] Comprida Lagoon in Brazil, Richmond Mine in California, acidic peatland in China Herbaspirillum sp. CLV-1, MTB from Nitrospirota , Proteobacteria , Desulfobacterota , Omnitrophota , SAR324 , Fibrobacterota , and Planctomycetota Acidic environments (pH 0.8–5.7) Intracellular acidic granules [ 17 , 42 , 43 ] Mono Lake, Soda Spring, and Armagosa Valley pond in California, USA Deltaproteobacteria strains ML-1, ZZ-1, and AV-1 Hyperalkaline environment (pH 9.0–10.0) Cytoplasmic buffering effect [ 39 , 44 ] Admiralty Bay at King George Island, Antarctica Magnetotactic cocci, vibrio, and bacilli Low temperature (<1 °C) / [ 48 ] Great Boiling Springs, Little Hot Creek, and Mickey Hot Springs, USA; Lake Miyun, China; Tengchong hot springs, China Candidatus Thermomagnetovibrio paiutensis strain HSMV-1, Nitrospirae strain MHS-1, Magnetotactic cocci, Nitrospirae MTB Moderately high temperature, temperature variation (9–70 °C) Temperature tolerance through MTB community rearrangement [ 51 – 54 , 94 ] Mickey Hot Springs, USA Nitrospirae strain MHS-1 Arsenic stress (~1 mg L −1 ) Magnetosome arsenic scavenging [ 53 ] Near space exposure Magnetospirillum gryphiswaldense strain MSR-1 …”

Virtual Special Issue of ACS Earth and Space Chemistry in Honor of Prof. Michael F. Hochella, Jr.

“…In addition, the three Hochella Symposium organizers were invited by Prof. Joel Blum, Editor-in-Chief of ACS Earth and Space Chemistry , to organize and serve as Guest Editors of a virtual special issue of this journal in honor of Mike Hochella. A total of 20 peer-reviewed manuscripts were accepted for publication in this virtual special issue (), with topics ranging from mineral/water interface chemistry and mineral/organic matter nanoparticles to organic matter/soil chemistry and microbial geochemistry studies. − These papers highlight the importance of nanogeoscience, mineral/aqueous solution interface chemistry, biogeochemistry, and organic matter/soil chemistry in understanding the Earth system.…”