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Herzig M, Hyötyläinen T, Vettese GF, Law GTW, Vierinen T, Bomberg M. Altering environmental conditions induce shifts in simulated deep terrestrial subsurface bacterial communities-Secretion of primary and secondary metabolites. Environ Microbiol 2024; 26:e16552. [PMID: 38098179 DOI: 10.1111/1462-2920.16552] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/24/2023] [Indexed: 01/30/2024]
Abstract
The deep terrestrial subsurface (DTS) harbours a striking diversity of microorganisms. However, systematic research on microbial metabolism, and how varying groundwater composition affects the bacterial communities and metabolites in these environments is lacking. In this study, DTS groundwater bacterial consortia from two Fennoscandian Shield sites were enriched and studied. We found that the enriched communities from the two sites consisted of distinct bacterial taxa, and alterations in the growth medium composition induced changes in cell counts. The lack of an exogenous organic carbon source (ECS) caused a notable increase in lipid metabolism in one community, while in the other, carbon starvation resulted in low overall metabolism, suggesting a dormant state. ECS supplementation increased CO2 production and SO4 2- utilisation, suggesting activation of a dissimilatory sulphate reduction pathway and sulphate-reducer-dominated total metabolism. However, both communities shared common universal metabolic features, most probably involving pathways needed for the maintenance of cell homeostasis (e.g., mevalonic acid pathway). Collectively, our findings indicate that the most important metabolites related to microbial reactions under varying growth conditions in enriched DTS communities include, but are not limited to, those linked to cell homeostasis, osmoregulation, lipid biosynthesis and degradation, dissimilatory sulphate reduction and isoprenoid production.
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Affiliation(s)
- Merja Herzig
- Faculty of Nuclear Sciences and Physical Engineering, Department of Nuclear Chemistry, Czech Technical University in Prague, Prague, Czech Republic
- Radiochemistry Unit, Faculty of Science, Department of Chemistry, University of Helsinki, Helsinki, Finland
| | - Tuulia Hyötyläinen
- School of Science and Technology, EnForce, Environment and Health and Systems Medicine, Örebro University, Örebro, Sweden
| | - Gianni F Vettese
- Radiochemistry Unit, Faculty of Science, Department of Chemistry, University of Helsinki, Helsinki, Finland
| | - Gareth T W Law
- Radiochemistry Unit, Faculty of Science, Department of Chemistry, University of Helsinki, Helsinki, Finland
| | - Taavi Vierinen
- Radiochemistry Unit, Faculty of Science, Department of Chemistry, University of Helsinki, Helsinki, Finland
| | - Malin Bomberg
- VTT Technical Research Centre of Finland, Espoo, Finland
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Nishimura H, Kouduka M, Fukuda A, Ishimura T, Amano Y, Beppu H, Miyakawa K, Suzuki Y. Anaerobic methane-oxidizing activity in a deep underground borehole dominantly colonized by Ca. Methanoperedenaceae. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:197-205. [PMID: 36779262 PMCID: PMC10464669 DOI: 10.1111/1758-2229.13146] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 01/24/2023] [Indexed: 05/06/2023]
Abstract
The family Ca. Methanoperedenaceae archaea mediates the anaerobic oxidation of methane (AOM) in different terrestrial environments. Using a newly developed high-pressure laboratory incubation system, we investigated 214- and 249-m deep groundwater samples at Horonobe Underground Research Laboratory, Japan, where the high and low abundances of Ca. Methanoperedenaceae archaea have been shown by genome-resolved metagenomics, respectively. The groundwater samples amended with 13 C-labelled methane and amorphous Fe(III) were incubated at a pressure of 1.6 MPa. After 3-7 days of incubation, the AOM rate was 45.8 ± 19.8 nM/day in 214-m groundwater. However, almost no activity was detected from 249-m groundwater. Based on the results from 16S rRNA gene analysis, the abundance of Ca. Methanoperedenaceae archaea was high in the 214-m deep groundwater sample, whereas Ca. Methanoperedenaceae archaea was undetected in the 249-m deep groundwater sample. These results support the in situ AOM activity of Ca. Methanoperedenaceae archaea in the 214-m deep subsurface borehole interval. Although the presence of Fe-bearing phyllosilicates was demonstrated in the 214-m deep groundwater, it needs to be determined whether Ca. Methanoperedenaceae archaea use the Fe-bearing phyllosilicates as in situ electron acceptors by high-pressure incubation amended with the Fe-bearing phyllosilicates.
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Affiliation(s)
- Hiroki Nishimura
- Department of Earth and Planetary ScienceThe University of TokyoTokyoJapan
| | - Mariko Kouduka
- Department of Earth and Planetary ScienceThe University of TokyoTokyoJapan
| | - Akari Fukuda
- Department of Earth and Planetary ScienceThe University of TokyoTokyoJapan
| | - Toyoho Ishimura
- Graduate School of Human and Environmental StudiesKyoto UniversityKyotoJapan
| | - Yuki Amano
- Horonobe Underground Research CenterJapan Atomic Energy AgencyHoronobe‐cho, HokkaidoJapan
- Nuclear Fuel Cycle Engineering LaboratoriesJapan Atomic Energy AgencyIbarakiJapan
| | - Hikari Beppu
- Nuclear Fuel Cycle Engineering LaboratoriesJapan Atomic Energy AgencyIbarakiJapan
| | - Kazuya Miyakawa
- Horonobe Underground Research CenterJapan Atomic Energy AgencyHoronobe‐cho, HokkaidoJapan
| | - Yohey Suzuki
- Department of Earth and Planetary ScienceThe University of TokyoTokyoJapan
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Nuppunen-Puputti M, Kietäväinen R, Kukkonen I, Bomberg M. Implications of a short carbon pulse on biofilm formation on mica schist in microcosms with deep crystalline bedrock groundwater. Front Microbiol 2023; 14:1054084. [PMID: 36819068 PMCID: PMC9932282 DOI: 10.3389/fmicb.2023.1054084] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/06/2023] [Indexed: 02/05/2023] Open
Abstract
Microbial life in the deep subsurface occupies rock surfaces as attached communities and biofilms. Previously, epilithic Fennoscandian deep subsurface bacterial communities were shown to host genetic potential, especially for heterotrophy and sulfur cycling. Acetate, methane, and methanol link multiple biogeochemical pathways and thus represent an important carbon and energy source for microorganisms in the deep subsurface. In this study, we examined further how a short pulse of low-molecular-weight carbon compounds impacts the formation and structure of sessile microbial communities on mica schist surfaces over an incubation period of ∼3.5 years in microcosms containing deep subsurface groundwater from the depth of 500 m, from Outokumpu, Finland. The marker gene copy counts in the water and rock phases were estimated with qPCR, which showed that bacteria dominated the mica schist communities with a relatively high proportion of epilithic sulfate-reducing bacteria in all microcosms. The dominant bacterial phyla in the microcosms were Proteobacteria, Firmicutes, and Actinobacteria, whereas most fungal genera belonged to Ascomycota and Basidiomycota. Dissimilarities between planktic and sessile rock surface microbial communities were observed, and the supplied carbon substrates led to variations in the bacterial community composition.
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Affiliation(s)
- Maija Nuppunen-Puputti
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland,*Correspondence: Maija Nuppunen-Puputti,
| | | | - Ilmo Kukkonen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Malin Bomberg
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
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Meyer-Dombard DR, Malas J. Advances in Defining Ecosystem Functions of the Terrestrial Subsurface Biosphere. Front Microbiol 2022; 13:891528. [PMID: 35722320 PMCID: PMC9201636 DOI: 10.3389/fmicb.2022.891528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/03/2022] [Indexed: 11/13/2022] Open
Abstract
The subsurface is one of the last remaining 'uncharted territories' of Earth and is now accepted as a biosphere in its own right, at least as critical to Earth systems as the surface biosphere. The terrestrial deep biosphere is connected through a thin veneer of Earth's crust to the surface biosphere, and many subsurface biosphere ecosystems are impacted by surface topography, climate, and near surface groundwater movement and represent a transition zone (at least ephemerally). Delving below this transition zone, we can examine how microbial metabolic functions define a deep terrestrial subsurface. This review provides a survey of the most recent advances in discovering the functional and genomic diversity of the terrestrial subsurface biosphere, how microbes interact with minerals and obtain energy and carbon in the subsurface, and considers adaptations to the presented environmental extremes. We highlight the deepest subsurface studies in deep mines, deep laboratories, and boreholes in crystalline and altered host rock lithologies, with a focus on advances in understanding ecosystem functions in a holistic manner.
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Nuppunen-Puputti M, Kietäväinen R, Raulio M, Soro A, Purkamo L, Kukkonen I, Bomberg M. Epilithic Microbial Community Functionality in Deep Oligotrophic Continental Bedrock. Front Microbiol 2022; 13:826048. [PMID: 35300483 PMCID: PMC8921683 DOI: 10.3389/fmicb.2022.826048] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/12/2022] [Indexed: 01/03/2023] Open
Abstract
The deep terrestrial biosphere hosts vast sessile rock surface communities and biofilms, but thus far, mostly planktic communities have been studied. We enriched deep subsurface microbial communities on mica schist in microcosms containing bedrock groundwater from the depth of 500 m from Outokumpu, Finland. The biofilms were visualized using scanning electron microscopy, revealing numerous different microbial cell morphologies and attachment strategies on the mica schist surface, e.g., bacteria with outer membrane vesicle-like structures, hair-like extracellular extensions, and long tubular cell structures expanding over hundreds of micrometers over mica schist surfaces. Bacterial communities were analyzed with amplicon sequencing showing that Pseudomonas, Desulfosporosinus, Hydrogenophaga, and Brevundimonas genera dominated communities after 8–40 months of incubation. A total of 21 metagenome assembled genomes from sessile rock surface metagenomes identified genes involved in biofilm formation, as well as a wide variety of metabolic traits indicating a high degree of environmental adaptivity to oligotrophic environment and potential for shifting between multiple energy or carbon sources. In addition, we detected ubiquitous organic carbon oxidation and capacity for arsenate and selenate reduction within our rocky MAGs. Our results agree with the previously suggested interaction between the deep subsurface microbial communities and the rock surfaces, and that this interaction could be crucial for sustaining life in the harsh anoxic and oligotrophic deep subsurface of crystalline bedrock environment.
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Affiliation(s)
| | | | - Mari Raulio
- European Chemicals Agency (ECHA), Helsinki, Finland
| | - Aino Soro
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
| | | | - Ilmo Kukkonen
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Malin Bomberg
- VTT Technical Research Centre of Finland Ltd., Espoo, Finland
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Active sulfur cycling in the terrestrial deep subsurface. ISME JOURNAL 2020; 14:1260-1272. [PMID: 32047278 DOI: 10.1038/s41396-020-0602-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 11/09/2022]
Abstract
The deep terrestrial subsurface remains an environment where there is limited understanding of the extant microbial metabolisms. At Olkiluoto, Finland, a deep geological repository is under construction for the final storage of spent nuclear fuel. It is therefore critical to evaluate the potential impact microbial metabolism, including sulfide generation, could have upon the safety of the repository. We investigated a deep groundwater where sulfate is present, but groundwater geochemistry suggests limited microbial sulfate-reducing activity. Examination of the microbial community at the genome-level revealed microorganisms with the metabolic capacity for both oxidative and reductive sulfur transformations. Deltaproteobacteria are shown to have the genetic capacity for sulfate reduction and possibly sulfur disproportionation, while Rhizobiaceae, Rhodocyclaceae, Sideroxydans, and Sulfurimonas oxidize reduced sulfur compounds. Further examination of the proteome confirmed an active sulfur cycle, serving for microbial energy generation and growth. Our results reveal that this sulfide-poor groundwater harbors an active microbial community of sulfate-reducing and sulfide-oxidizing bacteria, together mediating a sulfur cycle that remained undetected by geochemical monitoring alone. The ability of sulfide-oxidizing bacteria to limit the accumulation of sulfide was further demonstrated in groundwater incubations and highlights a potential sink for sulfide that could be beneficial for geological repository safety.
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