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Baumann NS, Sears JC, Broadie K. Experience-dependent MAPK/ERK signaling in glia regulates critical period remodeling of synaptic glomeruli. Cell Signal 2024; 120:111224. [PMID: 38740233 DOI: 10.1016/j.cellsig.2024.111224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/25/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Early-life critical periods allow initial sensory experience to remodel brain circuitry so that synaptic connectivity can be optimized to environmental input. In the Drosophila juvenile brain, olfactory sensory neuron (OSN) synaptic glomeruli are pruned by glial phagocytosis in dose-dependent response to early odor experience during a well-defined critical period. Extracellular signal-regulated kinase (ERK) separation of phases-based activity reporter of kinase (SPARK) biosensors reveal experience-dependent signaling in glia during this critical period. Glial ERK-SPARK signaling is depressed by removal of Draper receptors orchestrating glial phagocytosis. Cell-targeted genetic knockdown of glial ERK signaling reduces olfactory experience-dependent glial pruning of the OSN synaptic glomeruli in a dose-dependent mechanism. Noonan Syndrome is caused by gain-of-function mutations in protein tyrosine phosphatase non-receptor type 11 (PTPN11) inhibiting ERK signaling, and a glial-targeted patient-derived mutation increases experience-dependent glial ERK signaling and impairs experience-dependent glial pruning of the OSN synaptic glomeruli. We conclude that critical period experience drives glial ERK signaling that is required for dose-dependent pruning of brain synaptic glomeruli, and that altered glial ERK signaling impairs this critical period mechanism in a Noonan Syndrome disease model.
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Affiliation(s)
- Nicholas S Baumann
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - James C Sears
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA
| | - Kendal Broadie
- Department of Biological Sciences, Vanderbilt University and Medical Center, Nashville, TN 37235, USA; Department of Cell and Developmental Biology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA; Department of Pharmacology, Vanderbilt University and Medical Center, Nashville, TN 37235, USA; Vanderbilt Kennedy Center, Vanderbilt University and Medical Center, Nashville, TN 37235, USA; Vanderbilt Brain Institute, Vanderbilt University and Medical Center, Nashville, TN 37235, USA.
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2
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Katayama T, Nobu MK, Imachi H, Hosogi N, Meng XY, Morinaga K, Yoshioka H, Takahashi HA, Kamagata Y, Tamaki H. A Marine Group A isolate relies on other growing bacteria for cell wall formation. Nat Microbiol 2024; 9:1954-1963. [PMID: 38831032 DOI: 10.1038/s41564-024-01717-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/29/2024] [Indexed: 06/05/2024]
Abstract
Most of Earth's prokaryotes live under energy limitation, yet the full breadth of strategies that enable survival under such conditions remain poorly understood. Here we report the isolation of a bacterial strain, IA91, belonging to the candidate phylum Marine Group A (SAR406 or 'Candidatus Marinimicrobia') that is unable to synthesize the central cell wall compound peptidoglycan itself. Using cultivation experiments and microscopy, we show that IA91 growth and cell shape depend on other bacteria, deriving peptidoglycan, energy and carbon from exogenous muropeptide cell wall fragments released from growing bacteria. Reliance on exogenous muropeptides is traceable to the phylum's ancestor, with evidence of vertical inheritance across several classes. This dependency may be widespread across bacteria (16 phyla) based on the absence of key peptidoglycan synthesis genes. These results suggest that uptake of exogenous cell wall components could be a relevant and potentially common survival strategy in energy-limited habitats like the deep biosphere.
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Affiliation(s)
- Taiki Katayama
- Research Institute for Geo-Resources and Environment, Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan.
| | - Masaru K Nobu
- Bioproduction Research Institute, AIST, Tsukuba, Japan
- Institute for Extra-Cutting-Edge Science and Technology Avant-Garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Hiroyuki Imachi
- Institute for Extra-Cutting-Edge Science and Technology Avant-Garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Naoki Hosogi
- EM Application Department, EM Business Unit, JEOL, Ltd., Akishima, Japan
| | | | - Kana Morinaga
- Bioproduction Research Institute, AIST, Tsukuba, Japan
| | - Hideyoshi Yoshioka
- Research Institute for Geo-Resources and Environment, Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
| | - Hiroshi A Takahashi
- Research Institute of Earthquake and Volcano Geology, GSJ, AIST, Tsukuba, Japan
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3
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Meyer NR, Morono Y, Dekas AE. Single-cell analysis reveals an active and heterotrophic microbiome in the Guaymas Basin deep subsurface with significant inorganic carbon fixation by heterotrophs. Appl Environ Microbiol 2024; 90:e0044624. [PMID: 38709099 PMCID: PMC11334695 DOI: 10.1128/aem.00446-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 05/07/2024] Open
Abstract
The marine subsurface is a long-term sink of atmospheric carbon dioxide with significant implications for climate on geologic timescales. Subsurface microbial cells can either enhance or reduce carbon sequestration in the subsurface, depending on their metabolic lifestyle. However, the activity of subsurface microbes is rarely measured. Here, we used nanoscale secondary ion mass spectrometry (nanoSIMS) to quantify anabolic activity in 3,203 individual cells from the thermally altered deep subsurface in the Guaymas Basin, Mexico (3-75 m below the seafloor, 0-14°C). We observed that a large majority of cells were active (83%-100%), although the rates of biomass generation were low, suggesting cellular maintenance rather than doubling. Mean single-cell activity decreased with increasing sediment depth and temperature and was most strongly correlated with porewater sulfate concentrations. Intracommunity heterogeneity in microbial activity decreased with increasing sediment depth and age. Using a dual-isotope labeling approach, we determined that all active cells analyzed were heterotrophic, deriving the majority of their cellular carbon from organic sources. However, we also detected inorganic carbon assimilation in these heterotrophic cells, likely via processes such as anaplerosis, and determined that inorganic carbon contributes at least 5% of the total biomass carbon in heterotrophs in this community. Our results demonstrate that the deep marine biosphere at Guaymas Basin is largely active and contributes to subsurface carbon cycling primarily by not only assimilating organic carbon but also fixing inorganic carbon. Heterotrophic assimilation of inorganic carbon may be a small yet significant and widespread underappreciated source of labile carbon in the global subsurface. IMPORTANCE The global subsurface is the largest reservoir of microbial life on the planet yet remains poorly characterized. The activity of life in this realm has implications for long-term elemental cycling, particularly of carbon, as well as how life survives in extreme environments. Here, we recovered cells from the deep subsurface of the Guaymas Basin and investigated the level and distribution of microbial activity, the physicochemical drivers of activity, and the relative significance of organic versus inorganic carbon to subsurface biomass. Using a sensitive single-cell assay, we found that the majority of cells are active, that activity is likely driven by the availability of energy, and that although heterotrophy is the dominant metabolism, both organic and inorganic carbon are used to generate biomass. Using a new approach, we quantified inorganic carbon assimilation by heterotrophs and highlighted the importance of this often-overlooked mode of carbon assimilation in the subsurface and beyond.
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Affiliation(s)
- Nicolette R. Meyer
- Department of Earth System Science, Stanford University, Stanford, California, USA
| | - Yuki Morono
- Kochi Institute for Core Sample Research, Institute for Extra-cutting-edge Science and Technology Avantgarde Research (X-STAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan
| | - Anne E. Dekas
- Department of Earth System Science, Stanford University, Stanford, California, USA
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4
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Fifer LM, Wong ML. Quantifying the Potential for Nitrate-Dependent Iron Oxidation on Early Mars: Implications for the Interpretation of Gale Crater Organics. ASTROBIOLOGY 2024; 24:590-603. [PMID: 38805190 DOI: 10.1089/ast.2023.0109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Geological evidence and atmospheric and climate models suggest habitable conditions occurred on early Mars, including in a lake in Gale crater. Instruments aboard the Curiosity rover measured organic compounds of unknown provenance in sedimentary mudstones at Gale crater. Additionally, Curiosity measured nitrates in Gale crater sediments, which suggests that nitrate-dependent Fe2+ oxidation (NDFO) may have been a viable metabolism for putative martian life. Here, we perform the first quantitative assessment of an NDFO community that could have existed in an ancient Gale crater lake and quantify the long-term preservation of biological necromass in lakebed mudstones. We find that an NDFO community would have the capacity to produce cell concentrations of up to 106 cells mL-1, which is comparable to microbes in Earth's oceans. However, only a concentration of <104 cells mL-1, due to organisms that inefficiently consume less than 10% of precipitating nitrate, would be consistent with the abundance of organics found at Gale. We also find that meteoritic sources of organics would likely be insufficient as a sole source for the Gale crater organics, which would require a separate source, such as abiotic hydrothermal or atmospheric production or possibly biological production from a slowly turning over chemotrophic community.
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Affiliation(s)
- Lucas M Fifer
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, USA
- Astrobiology Program, University of Washington, Seattle, Washington, USA
| | - Michael L Wong
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC, USA
- NHFP Sagan Fellow, NASA Hubble Fellowship Program, Space Telescope Science Institute, Baltimore, Maryland, USA
- NASA Nexus for Exoplanet System Science, Virtual Planetary Laboratory Team, University of Washington, Seattle, Washington, USA
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5
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Luo K, Hu X, Li Y, Guo M, Liu X, Zhang Y, Zhuo W, Yang B, Wang X, Shi C. Revealing the mechanism of citral induced entry of Vibrio vulnificus into viable but not culturable (VBNC) state based on transcriptomics. Int J Food Microbiol 2024; 416:110656. [PMID: 38461733 DOI: 10.1016/j.ijfoodmicro.2024.110656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 02/24/2024] [Accepted: 02/27/2024] [Indexed: 03/12/2024]
Abstract
Citral has attracted much attention as a safe and effective plant-derived bacteriostatic agent. However, the ability of citral to induce the formation of VBNC state in Vibrio vulnificus has not been evaluated. In the present study, V. vulnificus was shown to be induced to form the VBNC state at 4.5 h and 3 h of citral treatment at 4MIC and 6MIC. Moreover, the citral-induced VBNC state of V. vulnificus maintained some respiratory chain activity and was able to recover well in both APW media, APW media supplemented with 5 % (v/v) Tween 80 and 2 mg/mL sodium pyruvate. Field emission and transmission electron microscopy showed that the external structure of the citral-induced VBNC V. vulnificus cells was shortened to short rods, with folded cell membrane, rough cell surface, and dense cytoplasm and loose nuclear material in the internal cell structure. In addition, the possible molecular mechanisms of citral-induced formation and recovery of V. vulnificus in the VBNC state were explored by transcriptomics. Transcriptome analyses revealed that 1118 genes were significantly altered upon entry into the VBNC state, and 1052 genes were changed after resuscitation. Most of the physiological activities related to energy production were inhibited in the citral-induced VBNC state of V. vulnificus; however, the bacteria retained its pathogenicity. The citral-induced resuscitation of V. vulnificus in the VBNC state selectively restored the activity of some genes related to bacterial growth and reproduction. Meanwhile, the expression levels of other genes may have been influenced by citral-induced resuscitation after the formation of the VBNC state. In conclusion, this study evaluated and analyzed the ability and possible mechanism of citral on the formation of VBNC state and the recovery of VBNC state of V. vulnificus, and made a comprehensive assessment for the safety of citral application in food production.
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Affiliation(s)
- Kunyao Luo
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Northwest A&F University Shenzhen Research Institute, Shenzhen, Guangdong 518057, China
| | - Xinquan Hu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yanzheng Li
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Meixian Guo
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xing Liu
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yingying Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Weiwei Zhuo
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Baowei Yang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xin Wang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Chao Shi
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China; Northwest A&F University Shenzhen Research Institute, Shenzhen, Guangdong 518057, China; Shaanxi Engineering Research Centre of Dairy Products Quality, Safety and Health, China.
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6
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Leavitt WD, Waldbauer J, Venceslau SS, Sim MS, Zhang L, Boidi FJ, Plummer S, Diaz JM, Pereira IAC, Bradley AS. Energy flux couples sulfur isotope fractionation to proteomic and metabolite profiles in Desulfovibrio vulgaris. GEOBIOLOGY 2024; 22:e12600. [PMID: 38725144 DOI: 10.1111/gbi.12600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 01/31/2024] [Accepted: 04/18/2024] [Indexed: 07/12/2024]
Abstract
Microbial sulfate reduction is central to the global carbon cycle and the redox evolution of Earth's surface. Tracking the activity of sulfate reducing microorganisms over space and time relies on a nuanced understanding of stable sulfur isotope fractionation in the context of the biochemical machinery of the metabolism. Here, we link the magnitude of stable sulfur isotopic fractionation to proteomic and metabolite profiles under different cellular energetic regimes. When energy availability is limited, cell-specific sulfate respiration rates and net sulfur isotope fractionation inversely covary. Beyond net S isotope fractionation values, we also quantified shifts in protein expression, abundances and isotopic composition of intracellular S metabolites, and lipid structures and lipid/water H isotope fractionation values. These coupled approaches reveal which protein abundances shift directly as a function of energy flux, those that vary minimally, and those that may vary independent of energy flux and likely do not contribute to shifts in S-isotope fractionation. By coupling the bulk S-isotope observations with quantitative proteomics, we provide novel constraints for metabolic isotope models. Together, these results lay the foundation for more predictive metabolic fractionation models, alongside interpretations of environmental sulfur and sulfate reducer lipid-H isotope data.
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Affiliation(s)
- William D Leavitt
- Department of Earth Sciences, Dartmouth College, Hanover, New Hampshire, USA
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Jacob Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Sofia S Venceslau
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Min Sub Sim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
| | - Lichun Zhang
- Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois, USA
| | - Flavia Jaquelina Boidi
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
- Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET-Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Sydney Plummer
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Julia M Diaz
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California, USA
| | - Inês A C Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Alexander S Bradley
- Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
- Division of Biology and Biomedical Sciences, Washington University in St. Louis, Saint Louis, Missouri, USA
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7
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Magkiriadou S, Stepp WL, Newman DK, Manley S, Racki LR. Polyphosphate affects cytoplasmic and chromosomal dynamics in nitrogen-starved Pseudomonas aeruginosa. Proc Natl Acad Sci U S A 2024; 121:e2313004121. [PMID: 38564631 PMCID: PMC11009631 DOI: 10.1073/pnas.2313004121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 01/26/2024] [Indexed: 04/04/2024] Open
Abstract
Polyphosphate (polyP) synthesis is a ubiquitous stress and starvation response in bacteria. In diverse species, mutants unable to make polyP have a wide variety of physiological defects, but the mechanisms by which this simple polyanion exerts its effects remain unclear. One possibility is that polyP's many functions stem from global effects on the biophysical properties of the cell. We characterize the effect of polyphosphate on cytoplasmic mobility under nitrogen-starvation conditions in the opportunistic pathogen Pseudomonas aeruginosa. Using fluorescence microscopy and particle tracking, we quantify the motion of chromosomal loci and cytoplasmic tracer particles. In the absence of polyP and upon starvation, we observe a 2- to 10-fold increase in mean cytoplasmic diffusivity. Tracer particles reveal that polyP also modulates the partitioning between a "more mobile" and a "less mobile" population: Small particles in cells unable to make polyP are more likely to be "mobile" and explore more of the cytoplasm, particularly during starvation. Concomitant with this larger freedom of motion in polyP-deficient cells, we observe decompaction of the nucleoid and an increase in the steady-state concentration of ATP. The dramatic polyP-dependent effects we observe on cytoplasmic transport properties occur under nitrogen starvation, but not carbon starvation, suggesting that polyP may have distinct functions under different types of starvation.
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Affiliation(s)
- Sofia Magkiriadou
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Willi L. Stepp
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA91125
| | - Suliana Manley
- Laboratory of Experimental Biophysics, Institute of Physics, École Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
| | - Lisa R. Racki
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, San Diego, CA92037
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8
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Kammel M, Erdmann C, Sawers RG. The formate-hydrogen axis and its impact on the physiology of enterobacterial fermentation. Adv Microb Physiol 2024; 84:51-82. [PMID: 38821634 DOI: 10.1016/bs.ampbs.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2024]
Abstract
Formic acid (HCOOH) and dihydrogen (H2) are characteristic products of enterobacterial mixed-acid fermentation, with H2 generation increasing in conjunction with a decrease in extracellular pH. Formate and acetyl-CoA are generated by radical-based and coenzyme A-dependent cleavage of pyruvate catalysed by pyruvate formate-lyase (PflB). Formate is also the source of H2, which is generated along with carbon dioxide through the action of the membrane-associated, cytoplasmically-oriented formate hydrogenlyase (FHL-1) complex. Synthesis of the FHL-1 complex is completely dependent on the cytoplasmic accumulation of formate. Consequently, formate determines its own disproportionation into H2 and CO2 by the FHL-1 complex. Cytoplasmic formate levels are controlled by FocA, a pentameric channel that translocates formic acid/formate bidirectionally between the cytoplasm and periplasm. Each protomer of FocA has a narrow hydrophobic pore through which neutral formic acid can pass. Two conserved amino acid residues, a histidine and a threonine, at the center of the pore control directionality of translocation. The histidine residue is essential for pH-dependent influx of formic acid. Studies with the formate analogue hypophosphite and amino acid variants of FocA suggest that the mechanisms of formic acid efflux and influx differ. Indeed, current data suggest, depending on extracellular formate levels, two separate uptake mechanisms exist, both likely contributing to maintain pH homeostasis. Bidirectional formate/formic acid translocation is dependent on PflB and influx requires an active FHL-1 complex. This review describes the coupling of formate and H2 production in enterobacteria.
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Affiliation(s)
- Michelle Kammel
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Saale, Germany
| | - Christopher Erdmann
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Saale, Germany
| | - R Gary Sawers
- Institute of Microbiology, Martin Luther University Halle-Wittenberg, Halle, Saale, Germany.
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9
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Sarkar J, Mondal M, Bhattacharya S, Dutta S, Chatterjee S, Mondal N, N S, Peketi A, Mazumdar A, Ghosh W. Extremely oligotrophic and complex-carbon-degrading microaerobic bacteria from Arabian Sea oxygen minimum zone sediments. Arch Microbiol 2024; 206:179. [PMID: 38498215 DOI: 10.1007/s00203-024-03875-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/23/2024] [Accepted: 01/26/2024] [Indexed: 03/20/2024]
Abstract
Sediments underlying marine hypoxic zones are huge sinks of unreacted complex organic matter, where despite acute O2 limitation, obligately aerobic bacteria thrive, and steady depletion of organic carbon takes place within a few meters below the seafloor. However, little knowledge exists about the sustenance and complex carbon degradation potentials of aerobic chemoorganotrophs in these sulfidic ecosystems. We isolated and characterized a number of aerobic bacterial chemoorganoheterotrophs from across a ~ 3 m sediment horizon underlying the perennial hypoxic zone of the eastern Arabian Sea. High levels of sequence correspondence between the isolates' genomes and the habitat's metagenomes and metatranscriptomes illustrated that the strains were widespread and active across the sediment cores explored. The isolates catabolized several complex organic compounds of marine and terrestrial origins in the presence of high or low, but not zero, O2. Some of them could also grow anaerobically on yeast extract or acetate by reducing nitrate and/or nitrite. Fermentation did not support growth, but enabled all the strains to maintain a fraction of their cell populations over prolonged anoxia. Under extreme oligotrophy, limited growth followed by protracted stationary phase was observed for all the isolates at low cell density, amid high or low, but not zero, O2 concentration. While population control and maintenance could be particularly useful for the strains' survival in the critically carbon-depleted layers below the explored sediment depths (core-bottom organic carbon: 0.5-1.0% w/w), metagenomic data suggested that in situ anoxia could be surmounted via potential supplies of cryptic O2 from previously reported sources such as Nitrosopumilus species.
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Affiliation(s)
- Jagannath Sarkar
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India.
| | - Mahamadul Mondal
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
| | - Sabyasachi Bhattacharya
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
- National Institute of Biomedical Genomics, Kalyani, West Bengal, India
| | - Subhajit Dutta
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
| | - Sumit Chatterjee
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
| | - Nibendu Mondal
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
- International Institute of Innovation and Technology, Kolkata, West Bengal, India
| | - Saran N
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India
| | - Aditya Peketi
- Geological Oceanography, CSIR National Institute of Oceanography, Dona Paula, Goa, 403004, India
| | - Aninda Mazumdar
- Geological Oceanography, CSIR National Institute of Oceanography, Dona Paula, Goa, 403004, India
| | - Wriddhiman Ghosh
- Department of Biological Sciences, Bose Institute, Kolkata, 700091, West Bengal, India.
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10
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Xu Q, Li L, Guo J, Guo H, Liu M, Guo S, Kuzyakov Y, Ling N, Shen Q. Active microbial population dynamics and life strategies drive the enhanced carbon use efficiency in high-organic matter soils. mBio 2024; 15:e0017724. [PMID: 38376207 PMCID: PMC10936188 DOI: 10.1128/mbio.00177-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 01/30/2024] [Indexed: 02/21/2024] Open
Abstract
Microbial carbon use efficiency (CUE) is a critical parameter that controls carbon storage in soil, but many uncertainties remain concerning adaptations of microbial communities to long-term fertilization that impact CUE. Based on H218O quantitative stable isotope probing coupled with metagenomic sequencing, we disentangled the roles of active microbial population dynamics and life strategies for CUE in soils after a long-term (35 years) mineral or organic fertilization. We found that the soils rich in organic matter supported high microbial CUE, indicating a more efficient microbial biomass formation and a greater carbon sequestration potential. Organic fertilizers supported active microbial communities characterized by high diversity and a relative increase in net growth rate, as well as an anabolic-biased carbon cycling, which likely explains the observed enhanced CUE. Overall, these results highlight the role of population dynamics and life strategies in understanding and predicting microbial CUE and sequestration in soil.IMPORTANCEMicrobial CUE is a major determinant of global soil organic carbon storage. Understanding the microbial processes underlying CUE can help to maintain soil sustainable productivity and mitigate climate change. Our findings indicated that active microbial communities, adapted to long-term organic fertilization, exhibited a relative increase in net growth rate and a preference for anabolic carbon cycling when compared to those subjected to chemical fertilization. These shifts in population dynamics and life strategies led the active microbes to allocate more carbon to biomass production rather than cellular respiration. Consequently, the more fertile soils may harbor a greater microbially mediated carbon sequestration potential. This finding is of great importance for manipulating microorganisms to increase soil C sequestration.
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Affiliation(s)
- Qicheng Xu
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
- Centre for Grassland Microbiome, State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Ling Li
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Junjie Guo
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Hanyue Guo
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Manqiang Liu
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
- Centre for Grassland Microbiome, State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Shiwei Guo
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
| | - Yakov Kuzyakov
- Department of Soil Science of Temperate Ecosystems, University of Gottingen, Göttingen, Germany
- Department of Agricultural Soil Science, University of Gottingen, Göttingen, Germany
- Peoples Friendship University of Russia (RUDN University), Moscow, Russia
| | - Ning Ling
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
- Centre for Grassland Microbiome, State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agricultural Science and Technology, Lanzhou University, Lanzhou, Gansu, China
| | - Qirong Shen
- Jiangsu Collaborative Innovation Center for Solid Organic Waste Resource Utilization, Nanjing Agricultural University, Nanjing, China
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11
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Ortega-Arzola E, Higgins PM, Cockell CS. The minimum energy required to build a cell. Sci Rep 2024; 14:5267. [PMID: 38438463 PMCID: PMC11306549 DOI: 10.1038/s41598-024-54303-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/11/2024] [Indexed: 03/06/2024] Open
Abstract
Understanding the energy requirements for cell synthesis accurately and comprehensively has been a longstanding challenge. We introduce a computational model that estimates the minimum energy necessary to build any cell from its constituent parts. This method combines omics and internal cell compositions from various sources to calculate the Gibbs Free Energy of biosynthesis independently of specific metabolic pathways. Our public tool, Synercell, can be used with other models for minumum species-specific energy estimations in any well-sequenced species. The energy for synthesising the genome, transcriptome, proteome, and lipid bilayer of four cell types: Escherichia coli, Saccharomyces cerevisiae, an average mammalian cell and JCVI-syn3A were estimated. Their modelled minimum synthesis energies at 298 K were 9.54 × 10 - 11 J/cell, 4.99 × 10 - 9 J/cell, 3.71 × 10 - 7 J/cell and 3.69 × 10 - 12 respectively. Gram-for-gram synthesis of lipid bilayers requires the most energy, followed by the proteome, genome, and transcriptome. The average per gram cost of biomass synthesis is in the 300s of J/g for all four cells. Implications for the generalisability of cell construction and applications to biogeosciences, cellular biology, biotechnology, and astrobiology are discussed.
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Affiliation(s)
- Edwin Ortega-Arzola
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK.
| | - Peter M Higgins
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
- Department of Earth Sciences, University of Toronto, Toronto, ON, Canada
| | - Charles S Cockell
- UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK
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12
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Liao L, Yu D, Xu L, Hu Q, Liang T, Chen L, Zhu Q, Liu S, Zhong A. Submersed macrophytes Vallisneria natans and Vallisneria spinulosa improve water quality and affect microbial communities in sediment and water columns. Heliyon 2024; 10:e25942. [PMID: 38371958 PMCID: PMC10873746 DOI: 10.1016/j.heliyon.2024.e25942] [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: 12/20/2023] [Revised: 01/19/2024] [Accepted: 02/05/2024] [Indexed: 02/20/2024] Open
Abstract
Healthy aquatic ecosystems are essential for human beings. However, anthropogenic activities severely worsen water quality. In this study, using assembling mesocosms, we developed an efficient and easy-to-handle method to monitor the water quality by measuring the electrical conductivity (EC) of water. Our data demonstrate that the growth of two submersed macrophytes, Vallisnerianatans and Vallisneria spinulosa, improves water quality by decreasing EC. Furthermore, using high-throughput DNA sequencing, we analyzed the microbial community abundance and structure in sediment and water columns with or without plant growth. We generated 33,775 amplicon sequence variants from 69 samples of four sediment groups (BkM, CtM, VnR, and VsR) and three water column sample groups (CtW, VnW, and VsW). The results show that the relative abundance of bacteria was higher in the sediment than in the water column. Moreover, the diversity and composition of microbiomes were altered by Vallisneria spp. growth, and the α-diversity of the microbial communities decreased due to submersed macrophytes in both the sediment and water columns. The β-diversity of the microbial communities also varied significantly with or without Vallisneria spp. growth for both the sediment and water columns.
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Affiliation(s)
| | | | - Lei Xu
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Qian Hu
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Tongjun Liang
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Ludan Chen
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Qiuping Zhu
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Songping Liu
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
| | - Aiwen Zhong
- Lushan Botanical Garden, Chinese Academy of Science, Jiujiang, 332900, Jiangxi, China
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13
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Raes B, Wang J, Horemans B, Dirckx L, Waldherr S, Kohler HPE, Springael D. The Growth Yield of Aminobacter niigataensis MSH1 on the Micropollutant 2,6-Dichlorobenzamide Decreases Substantially at Trace Substrate Concentrations. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:2859-2869. [PMID: 38289638 DOI: 10.1021/acs.est.3c06883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2024]
Abstract
2,6-Dichlorobenzamide (BAM) is an omnipresent micropollutant in European groundwaters. Aminobacter niigataensis MSH1 is a prime candidate for biologically treating BAM-contaminated groundwater since this organism is capable of utilizing BAM as a carbon and energy source. However, detailed information on the BAM degradation kinetics by MSH1 at trace concentrations is lacking, while this knowledge is required for predicting and optimizing the degradation process. Contaminating assimilable organic carbon (AOC) in media makes the biodegradation experiment a mixed-substrate assay and hampers exploration of pollutant degradation at trace concentrations. In this study, we examined how the BAM concentration affects MSH1 growth and BAM substrate utilization kinetics in a AOC-restricted background to avoid mixed-substrate conditions. Conventional Monod kinetic models were unable to predict kinetic parameters at low concentrations from kinetics determined at high concentrations. Growth yields on BAM were concentration-dependent and decreased substantially at trace concentrations; i.e., growth of MSH1 diminished until undetectable levels at BAM concentrations below 217 μg-C/L. Nevertheless, BAM degradation continued. Decreasing growth yields at lower BAM concentrations might relate to physiological adaptations to low substrate availability or decreased expression of downstream steps of the BAM catabolic pathway beyond 2,6-dichlorobenzoic acid (2,6-DCBA) that ultimately leads to Krebs cycle intermediates for growth and energy conservation.
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Affiliation(s)
- Bart Raes
- Division of Soil and Water Management, KU Leuven, Heverlee B-3001, Belgium
| | - Jinsong Wang
- Division of Soil and Water Management, KU Leuven, Heverlee B-3001, Belgium
| | - Benjamin Horemans
- Division of Soil and Water Management, KU Leuven, Heverlee B-3001, Belgium
| | - Lode Dirckx
- Division of Soil and Water Management, KU Leuven, Heverlee B-3001, Belgium
| | - Steffen Waldherr
- Chemical Reactor Engineering and Safety (CREaS), KU Leuven, Heverlee B-3001, Belgium
| | - Hans-Peter E Kohler
- Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Switzerland
| | - Dirk Springael
- Division of Soil and Water Management, KU Leuven, Heverlee B-3001, Belgium
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14
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Flamholz AI, Goyal A, Fischer WW, Newman DK, Phillips R. The proteome is a terminal electron acceptor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.31.578293. [PMID: 38352589 PMCID: PMC10862836 DOI: 10.1101/2024.01.31.578293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/25/2024]
Abstract
Microbial metabolism is impressively flexible, enabling growth even when available nutrients differ greatly from biomass in redox state. E. coli, for example, rearranges its physiology to grow on reduced and oxidized carbon sources through several forms of fermentation and respiration. To understand the limits on and evolutionary consequences of metabolic flexibility, we developed a mathematical model coupling redox chemistry with principles of cellular resource allocation. Our integrated model clarifies key phenomena, including demonstrating that autotrophs grow slower than heterotrophs because of constraints imposed by intracellular production of reduced carbon. Our model further indicates that growth is improved by adapting the redox state of biomass to nutrients, revealing an unexpected mode of evolution where proteins accumulate mutations benefiting organismal redox balance.
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Affiliation(s)
- Avi I. Flamholz
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA 91125
| | - Akshit Goyal
- Physics of Living Systems, Department of Physics, Massachusetts Institute of Technology; Cambridge, MA 02139
- International Centre for Theoretical Sciences, Tata Institute of Fundamental Research; Bengaluru 560089
| | - Woodward W. Fischer
- Division of Geological & Planetary Sciences, California Institute of Technology; Pasadena, CA 91125
| | - Dianne K. Newman
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA 91125
- Division of Geological & Planetary Sciences, California Institute of Technology; Pasadena, CA 91125
| | - Rob Phillips
- Division of Biology and Biological Engineering, California Institute of Technology; Pasadena, CA 91125
- Department of Physics, California Institute of Technology; Pasadena, CA 91125, USA
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15
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Rothman DH. Slow closure of Earth's carbon cycle. Proc Natl Acad Sci U S A 2024; 121:e2310998121. [PMID: 38241442 PMCID: PMC10823250 DOI: 10.1073/pnas.2310998121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 12/07/2023] [Indexed: 01/21/2024] Open
Abstract
Carbon near the Earth's surface cycles between the production and consumption of organic carbon; the former sequesters carbon dioxide while the latter releases it. Microbes attempt to close the loop, but the longer organic matter survives, the slower microbial degradation becomes. This aging effect leaves observable quantitative signatures: Organic matter decays at rates that are inversely proportional to its age, while microbial populations and concentrations of organic carbon in ocean sediments decrease at distinct powers of age. Yet mechanisms that predict this collective organization remain unknown. Here, I show that these and other observations follow from the assumption that the decay of organic matter is limited by progressively rare extreme fluctuations in the energy available to microbes for decomposition. The theory successfully predicts not only observed scaling exponents but also a previously unobserved scaling regime that emerges when microbes subsist on the minimum energy flux required for survival. The resulting picture suggests that the carbon cycle's age-dependent dynamics are analogous to the slow approach to equilibrium in disordered systems. The impact of these slow dynamics is profound: They preclude complete oxidation of organic carbon in sediments, thereby freeing molecular oxygen to accumulate in the atmosphere.
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Affiliation(s)
- Daniel H Rothman
- Lorenz Center, Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139
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16
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Hoehler TM, Amend JP, Jørgensen BB, Orphan VJ, Lever MA. Editorial: Studies on life at the energetic edge - from laboratory experiments to field-based investigations, volume II. Front Microbiol 2024; 14:1351761. [PMID: 38249447 PMCID: PMC10797740 DOI: 10.3389/fmicb.2023.1351761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 12/11/2023] [Indexed: 01/23/2024] Open
Affiliation(s)
- Tori M. Hoehler
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, United States
| | - Jan P. Amend
- Department of Earth Sciences and Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | | | - Victoria J. Orphan
- Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States
| | - Mark A. Lever
- Marine Science Institute, The University of Texas at Austin, Austin, TX, United States
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17
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Schauberger C, Thamdrup B, Lemonnier C, Trouche B, Poulain J, Wincker P, Arnaud-Haond S, Glud RN, Maignien L. Metagenome-assembled genomes of deep-sea sediments: changes in microbial functional potential lag behind redox transitions. ISME COMMUNICATIONS 2024; 4:ycad005. [PMID: 38282644 PMCID: PMC10809760 DOI: 10.1093/ismeco/ycad005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 11/21/2023] [Accepted: 11/22/2023] [Indexed: 01/30/2024]
Abstract
Hadal sediments are hotspots of microbial activity in the deep sea and exhibit strong biogeochemical gradients. But although these gradients are widely assumed to exert selective forces on hadal microbial communities, the actual relationship between biogeochemistry, functional traits, and microbial community structure remains poorly understood. We tested whether the biogeochemical conditions in hadal sediments select for microbes based on their genomic capacity for respiration and carbohydrate utilization via a metagenomic analysis of over 153 samples from the Atacama Trench region (max. depth = 8085 m). The obtained 1357 non-redundant microbial genomes were affiliated with about one-third of all known microbial phyla, with more than half belonging to unknown genera. This indicated that the capability to withstand extreme hydrostatic pressure is a phylogenetically widespread trait and that hadal sediments are inhabited by diverse microbial lineages. Although community composition changed gradually over sediment depth, these changes were not driven by selection for respiratory or carbohydrate degradation capability in the oxic and nitrogenous zones, except in the case of anammox bacteria and nitrifying archaea. However, selection based on respiration and carbohydrate degradation capacity did structure the communities of the ferruginous zone, where aerobic and nitrogen respiring microbes declined exponentially (half-life = 125-419 years) and were replaced by subsurface communities. These results highlight a delayed response of microbial community composition to selective pressure imposed by redox zonation and indicated that gradual changes in microbial composition are shaped by the high-resilience and slow growth of microbes in the seafloor.
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Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
| | - Clarisse Lemonnier
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Blandine Trouche
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
| | - Julie Poulain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS,University of Évry, Université Paris-Saclay, 91057 Evry, France
| | - Sophie Arnaud-Haond
- MARBEC, CNRS, IRD, Institut Français de Recherche pour L'Exploitation de la Mer, Univ Montpellier, 34200 Sète, France
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Campusvej 55, Odense M 5230, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan
| | - Lois Maignien
- Microbiology of Extreme Environments Laboratory, CNRS, IFREMER, Univ Brest, F-29280 Plouzané, France
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18
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Meier D, van Grinsven S, Michel A, Eickenbusch P, Glombitza C, Han X, Fiskal A, Bernasconi S, Schubert CJ, Lever MA. Hydrogen-independent CO 2 reduction dominates methanogenesis in five temperate lakes that differ in trophic states. ISME COMMUNICATIONS 2024; 4:ycae089. [PMID: 38988698 PMCID: PMC11235125 DOI: 10.1093/ismeco/ycae089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/20/2024] [Accepted: 06/20/2024] [Indexed: 07/12/2024]
Abstract
Emissions of microbially produced methane (CH4) from lake sediments are a major source of this potent greenhouse gas to the atmosphere. The rates of CH4 production and emission are believed to be influenced by electron acceptor distributions and organic carbon contents, which in turn are affected by anthropogenic inputs of nutrients leading to eutrophication. Here, we investigate how eutrophication influences the abundance and community structure of CH4 producing Archaea and methanogenesis pathways across time-resolved sedimentary records of five Swiss lakes with well-characterized trophic histories. Despite higher CH4 concentrations which suggest higher methanogenic activity in sediments of eutrophic lakes, abundances of methanogens were highest in oligotrophic lake sediments. Moreover, while the methanogenic community composition differed significantly at the lowest taxonomic levels (OTU), depending on whether sediment layers had been deposited under oligotrophic or eutrophic conditions, it showed no clear trend in relation to in situ distributions of electron acceptors. Remarkably, even though methanogenesis from CO2-reduction was the dominant pathway in all sediments based on carbon isotope fractionation values, taxonomic identities, and genomes of resident methanogens, CO2-reduction with hydrogen (H2) was thermodynamically unfavorable based on measured reactant and product concentrations. Instead, strong correlations between genomic abundances of CO2-reducing methanogens and anaerobic bacteria with potential for extracellular electron transfer suggest that methanogenic CO2-reduction in lake sediments is largely powered by direct electron transfer from syntrophic bacteria without involvement of H2 as an electron shuttle.
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Affiliation(s)
- Dimitri Meier
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
- Ecological Microbiology, Bayreuth Center of Ecology and Environmental Research, University of Bayreuth, Dr. Hans-Frisch-Straße 1-3, 95448 Bayreuth, Germany
| | - Sigrid van Grinsven
- Department of Surface Waters-Research and Management, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Seestrasse 79, 6047 Kastanienbaum, Switzerland
- Geomicrobiology, Department of Geosciences, Eberhard Karls Universität Tübingen (Tübingen University), Schnarrenbergstraße 94-96, 72076 Tübingen, Germany
| | - Anja Michel
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Philip Eickenbusch
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Clemens Glombitza
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Xingguo Han
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Annika Fiskal
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
| | - Stefano Bernasconi
- Department of Earth Sciences, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Geological Institute, Sonneggstrasse 5, 8092 Zurich, Switzerland
| | - Carsten J Schubert
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
- Department of Surface Waters-Research and Management, Swiss Federal Institute of Aquatic Science and Technology (EAWAG), Seestrasse 79, 6047 Kastanienbaum, Switzerland
| | - Mark A Lever
- Department of Environmental Systems Science, Institute of Biogeochemistry and Pollutant Dynamics, Swiss Federal Institute of Technology, Zurich (ETH Zurich), Universitätstrasse 16, 8092 Zurich, Switzerland
- Marine Science Institute, Department of Marine Sciences, University of Texas at Austin, 750 Channel View Drive, Port Aransas, TX 78373, United States
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19
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Karaś P, Kochanowicz K, Pitek M, Domanski P, Obuchowski I, Tomiczek B, Liberek K. Evolution towards simplicity in bacterial small heat shock protein system. eLife 2023; 12:RP89813. [PMID: 38063373 PMCID: PMC10708888 DOI: 10.7554/elife.89813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2023] Open
Abstract
Evolution can tinker with multi-protein machines and replace them with simpler single-protein systems performing equivalent functions in an equally efficient manner. It is unclear how, on a molecular level, such simplification can arise. With ancestral reconstruction and biochemical analysis, we have traced the evolution of bacterial small heat shock proteins (sHsp), which help to refold proteins from aggregates using either two proteins with different functions (IbpA and IbpB) or a secondarily single sHsp that performs both functions in an equally efficient way. Secondarily single sHsp evolved from IbpA, an ancestor specialized in strong substrate binding. Evolution of an intermolecular binding site drove the alteration of substrate binding properties, as well as the formation of higher-order oligomers. Upon two mutations in the α-crystallin domain, secondarily single sHsp interacts with aggregated substrates less tightly. Paradoxically, less efficient binding positively influences the ability of sHsp to stimulate substrate refolding, since the dissociation of sHps from aggregates is required to initiate Hsp70-Hsp100-dependent substrate refolding. After the loss of a partner, IbpA took over its role in facilitating the sHsp dissociation from an aggregate by weakening the interaction with the substrate, which became beneficial for the refolding process. We show that the same two amino acids introduced in modern-day systems define whether the IbpA acts as a single sHsp or obligatorily cooperates with an IbpB partner. Our discoveries illuminate how one sequence has evolved to encode functions previously performed by two distinct proteins.
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Affiliation(s)
- Piotr Karaś
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Klaudia Kochanowicz
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Marcin Pitek
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Przemyslaw Domanski
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Igor Obuchowski
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Barlomiej Tomiczek
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
| | - Krzysztof Liberek
- Intercollegiate Faculty of Biotechnology UG-MUG, University of GdanskGdańskPoland
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20
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Sun J, Feng Y, Zheng R, Kong L, Wu X, Zhang K, Zhou J, Liu S. Chameleon-like Anammox Bacteria for Surface Color Change after Suffering Starvation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2023; 57:15087-15098. [PMID: 37754765 DOI: 10.1021/acs.est.3c04000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/28/2023]
Abstract
Bacteria are often exposed to long-term starvation during transportation and storage, during which a series of enzymes and metabolic pathways are activated to ensure survival. However, why the surface color of the bacteria changes during starvation is still not well-known. In this study, we found black anammox consortia suffering from long-term starvation contained 0.86 mmol gVSS-1 cytochrome c, which had no significant discrepancy compared with the red anammox consortia (P > 0.05), indicating cytochrome c was not the key issue for chromaticity change. Conversely, we found that under starvation conditions cysteine degradation is an important metabolic pathway for the blackening of the anammox consortia for H2S production. In particular, anammox bacteria contain large amounts of iron-rich nanoparticles, cytochrome c, and other iron-sulfur clusters that are converted to produce free iron. H2S combines with free iron in bacteria to form Fe-S compounds, which eventually exist stably as FeS2, mainly in the extracellular space. Interestingly, FeS2 could be oxidized by air aeration, which makes the consortia turn red again. The unique self-protection mechanism makes the whole consortia appear black, avoiding inhibition by high concentrations of H2S and achieving Fe storage. This study expands the understanding of the metabolites of anammox bacteria as well as the bacterial survival mechanism during starvation.
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Affiliation(s)
- Jingqi Sun
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Yiming Feng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Ru Zheng
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Lingrui Kong
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Xiaogang Wu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Kuo Zhang
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Jianhang Zhou
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
| | - Sitong Liu
- College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
- Key Laboratory of Water and Sediment Sciences, Ministry of Education of China, Beijing 100871, China
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21
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Schauberger C, Seki D, Cutts EM, Glud RN, Thamdrup B. Uniform selective pressures within redox zones drive gradual changes in microbial community composition in hadal sediments. Environ Microbiol 2023; 25:1594-1604. [PMID: 36999247 DOI: 10.1111/1462-2920.16377] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 03/19/2023] [Indexed: 04/01/2023]
Abstract
Microbial communities in marine sediments are highly diverse, yet the processes that give rise to this complexity are unclear. It has been proposed that benthic microbial communities must be continuously re-seeded from the water column because dispersal within the sediment is severely limited. Previous studies consistently report that the composition of the microbial community gradually changes with sediment depth. However, the relative contributions of the processes that underlie these compositional gradients have not been determined, and it is unknown whether microbial dispersal is indeed too slow to outpace burial. Here, we applied ecological statistical frameworks to 16S rRNA gene amplicon-based community composition data from Atacama Trench sediments to investigate the links between biogeochemistry, burial, and microbial community assembly processes. We confirm that dispersal limitation affects microbial communities and find that gradual changes in community composition are driven by selective pressures that change abruptly across the discrete boundaries between redox zones rather than along continuous biogeochemical gradients, while selective pressures are uniform within each zone. The gradual changes in community composition over centimetres of depth within a zone hence reflects a decades-long response to the abruptly changing selective pressures.
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Affiliation(s)
- Clemens Schauberger
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
| | - David Seki
- Centre for Microbiology and Environmental Systems Science, Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria
| | - Elise M Cutts
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Ronnie N Glud
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
- Department of Ocean and Environmental Sciences, Tokyo University of Marine Science and Technology, 4-5-7 Konan, Minato-ku, Tokyo, 108-8477, Japan
| | - Bo Thamdrup
- Hadal & Nordcee, Department of Biology, University of Southern Denmark, Odense, Denmark
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Kanaan G, Hoehler TM, Iwahana G, Deming JW. Modeled energetics of bacterial communities in ancient subzero brines. Front Microbiol 2023; 14:1206641. [PMID: 37564288 PMCID: PMC10411740 DOI: 10.3389/fmicb.2023.1206641] [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: 04/16/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Cryopeg brines are isolated volumes of hypersaline water in subzero permafrost. The cryopeg system at Utqiaġvik, Alaska, is estimated to date back to 40 ka BP or earlier, a remnant of a late Pleistocene Ocean. Surprisingly, the cryopeg brines contain high concentrations of organic carbon, including extracellular polysaccharides, and high densities of bacteria. How can these physiologically extreme, old, and geologically isolated systems support such an ecosystem? This study addresses this question by examining the energetics of the Utqiaġvik cryopeg brine ecosystem. Using literature-derived assumptions and new measurements on archived borehole materials, we first estimated the quantity of organic carbon when the system formed. We then considered two bacterial growth trajectories to calculate the lower and upper bounds of the cell-specific metabolic rate of these communities. These bounds represent the first community estimates of metabolic rate in a subzero hypersaline environment. To assess the plausibility of the different growth trajectories, we developed a model of the organic carbon cycle and applied it to three borehole scenarios. We also used dissolved inorganic carbon and nitrogen measurements to independently estimate the metabolic rate. The model reconstructs the growth trajectory of the microbial community and predicts the present-day cell density and organic carbon content. Model input included measured rates of the in-situ enzymatic conversion of particulate to dissolved organic carbon under subzero brine conditions. A sensitivity analysis of model parameters was performed, revealing an interplay between growth rate, cell-specific metabolic rate, and extracellular enzyme activity. This approach allowed us to identify plausible growth trajectories consistent with the observed bacterial densities in the cryopeg brines. We found that the cell-specific metabolic rate in this system is relatively high compared to marine sediments. We attribute this finding to the need to invest energy in the production of extracellular enzymes, for generating bioavailable carbon from particulate organic carbon, and the production of extracellular polysaccharides for cryoprotection and osmoprotection. These results may be relevant to other isolated systems in the polar regions of Earth and to possible ice-bound brines on worlds such as Europa, Enceladus, and Mars.
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Affiliation(s)
- Georges Kanaan
- School of Oceanography and Astrobiology Program, University of Washington, Seattle, WA, United States
| | | | - Go Iwahana
- International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, AK, United States
| | - Jody W. Deming
- School of Oceanography and Astrobiology Program, University of Washington, Seattle, WA, United States
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23
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Li H, Zhou H, Yang S, Dai X. Stochastic and Deterministic Assembly Processes in Seamount Microbial Communities. Appl Environ Microbiol 2023; 89:e0070123. [PMID: 37404136 PMCID: PMC10370332 DOI: 10.1128/aem.00701-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 06/07/2023] [Indexed: 07/06/2023] Open
Abstract
Seamounts are ubiquitous in the ocean. However, little is known about how seamount habitat features influence the local microbial community. In this study, the microbial populations of sediment cores from sampling depths of 0.1 to 35 cm from 10 seamount summit sites with a water depth of 1,850 to 3,827 m across the South China Sea (SCS) Basin were analyzed. Compared with nonseamount ecosystems, isolated seamounts function as oases for microbiomes, with average moderate to high levels of microbial abundance, richness, and diversity, and they harbor distinct microbial communities. The distinct characteristics of different seamounts provide a high level of habitat heterogeneity, resulting in the wide range of microbial community diversity observed across all seamounts. Using dormant thermospores as tracers to study the effect of dispersal by ocean currents, the observed distance-decay biogeography across different seamounts shaped simultaneously by the seamounts' naturally occurring heterogeneous habitat and the limitation of ocean current dispersal was found. We also established a framework that links initial community assembly with successional dynamics in seamounts. Seamounts provide resource-rich and dynamic environments, which leads to a dominance of stochasticity during initial community establishment in surface sediments. However, a progressive increase in deterministic environmental selection, correlated with resource depletion in subsurface sediments, leads to the selective growth of rare species of surface sediment communities in shaping the subsurface community. Overall, the study indicates that seamounts are a previously ignored oasis in the deep sea. This study also provides a case study for understanding the microbial ecology in globally widespread seamounts. IMPORTANCE Although there are approximately 25 million seamounts in the ocean, surprisingly little is known about seamount microbial ecology. We provide evidence that seamounts are island-like habitats harboring microbial communities distinct from those of nonseamount habitats, and they exhibit a distance-decay pattern. Environmental selection and dispersal limitation simultaneously shape the observed biogeography. Coupling empirical data with a null mode revealed a shift in the type and strength, which controls microbial community assembly and succession from the seamount surface to the subsurface sediments as follows: (i) community assembly is initially primarily driven by stochastic processes such as dispersal limitation, and (ii) changes in the subsurface environment progressively increase the importance of environmental selection. This case study contributes to the mechanistic understanding essential for a predictive microbial ecology of seamounts.
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Affiliation(s)
- Haizhou Li
- East China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Shanghai, China
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Huaiyang Zhou
- State Key Laboratory of Marine Geology, Tongji University, Shanghai, China
| | - Shanshan Yang
- College of Marine Science and Technology, China University of Geosciences, Wuhan, Hubei, China
- Institute for Advanced Marine Research, China University of Geosciences, Guangzhou, China
| | - Xin Dai
- State Key Laboratory of Microbial Resources, Institutes of Microbiology, Chinese Academy of Sciences, Beijing, China
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24
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Jaussi M, Jørgensen BB, Kjeldsen KU, Lomstein BA, Pearce C, Seidenkantz MS, Røy H. Cell-specific rates of sulfate reduction and fermentation in the sub-seafloor biosphere. Front Microbiol 2023; 14:1198664. [PMID: 37555068 PMCID: PMC10405931 DOI: 10.3389/fmicb.2023.1198664] [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: 04/01/2023] [Accepted: 07/05/2023] [Indexed: 08/10/2023] Open
Abstract
Microorganisms in subsurface sediments live from recalcitrant organic matter deposited thousands or millions of years ago. Their catabolic activities are low, but the deep biosphere is of global importance due to its volume. The stability of deeply buried sediments provides a natural laboratory where prokaryotic communities that live in steady state with their environments can be studied over long time scales. We tested if a balance is established between the flow of energy, the microbial community size, and the basal power requirement needed to maintain cells in sediments buried meters below the sea floor. We measured rates of carbon oxidation by sulfate reduction and counted the microbial cells throughout ten carefully selected sediment cores with ages from years to millions of years. The rates of carbon oxidation were converted to power (J s-1 i.e., Watt) using the Gibbs free energy of the anaerobic oxidation of complex organic carbon. We separated energy dissipation by fermentation from sulfate reduction. Similarly, we separated the community into sulfate reducers and non-sulfate reducers based on the dsrB gene, so that sulfate reduction could be related to sulfate reducers. We found that the per-cell sulfate reduction rate was stable near 10-2 fmol C cell-1 day-1 right below the zone of bioturbation and did not decrease with increasing depth and sediment age. The corresponding power dissipation rate was 10-17 W sulfate-reducing cell-1. The cell-specific power dissipation of sulfate reducers in old sediments was similar to the slowest growing anaerobic cultures. The energy from mineralization of organic matter that was not dissipated by sulfate reduction was distributed evenly to all cells that did not possess the dsrB gene, i.e., cells operationally defined as fermenting. In contrast to sulfate reducers, the fermenting cells had decreasing catabolism as the sediment aged. A vast difference in power requirement between fermenters and sulfate reducers caused the microbial community in old sediments to consist of a minute fraction of sulfate reducers and a vast majority of fermenters.
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Affiliation(s)
- Marion Jaussi
- Department of Biology, Aarhus University, Aarhus, Denmark
| | | | | | | | - Christof Pearce
- Department of Geoscience, Aarhus University, Aarhus, Denmark
| | | | - Hans Røy
- Department of Biology, Aarhus University, Aarhus, Denmark
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25
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Leng H, Wang Y, Zhao W, Sievert SM, Xiao X. Identification of a deep-branching thermophilic clade sheds light on early bacterial evolution. Nat Commun 2023; 14:4354. [PMID: 37468486 DOI: 10.1038/s41467-023-39960-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 07/06/2023] [Indexed: 07/21/2023] Open
Abstract
It has been proposed that early bacteria, or even the last universal common ancestor of all cells, were thermophilic. However, research on the origin and evolution of thermophily is hampered by the difficulties associated with the isolation of deep-branching thermophilic microorganisms in pure culture. Here, we isolate a deep-branching thermophilic bacterium from a deep-sea hydrothermal vent, using a two-step cultivation strategy ("Subtraction-Suboptimal", StS) designed to isolate rare organisms. The bacterium, which we name Zhurongbacter thermophilus 3DAC, is a sulfur-reducing heterotroph that is phylogenetically related to Coprothermobacterota and other thermophilic bacterial groups, forming a clade that seems to represent a major, early-diverging bacterial lineage. The ancestor of this clade might be a thermophilic, strictly anaerobic, motile, hydrogen-dependent, and mixotrophic bacterium. Thus, our study provides insights into the early evolution of thermophilic bacteria.
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Affiliation(s)
- Hao Leng
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, China
| | - Yinzhao Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, China
| | - Weishu Zhao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
- International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, China
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Xiang Xiao
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China.
- International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, Guangdong, China.
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26
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Conrad R. Complexity of temperature dependence in methanogenic microbial environments. Front Microbiol 2023; 14:1232946. [PMID: 37485527 PMCID: PMC10359720 DOI: 10.3389/fmicb.2023.1232946] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 06/20/2023] [Indexed: 07/25/2023] Open
Abstract
There is virtually no environmental process that is not dependent on temperature. This includes the microbial processes that result in the production of CH4, an important greenhouse gas. Microbial CH4 production is the result of a combination of many different microorganisms and microbial processes, which together achieve the mineralization of organic matter to CO2 and CH4. Temperature dependence applies to each individual step and each individual microbe. This review will discuss the different aspects of temperature dependence including temperature affecting the kinetics and thermodynamics of the various microbial processes, affecting the pathways of organic matter degradation and CH4 production, and affecting the composition of the microbial communities involved. For example, it was found that increasing temperature results in a change of the methanogenic pathway with increasing contribution from mainly acetate to mainly H2/CO2 as immediate CH4 precursor, and with replacement of aceticlastic methanogenic archaea by thermophilic syntrophic acetate-oxidizing bacteria plus thermophilic hydrogenotrophic methanogenic archaea. This shift is consistent with reaction energetics, but it is not obligatory, since high temperature environments exist in which acetate is consumed by thermophilic aceticlastic archaea. Many studies have shown that CH4 production rates increase with temperature displaying a temperature optimum and a characteristic apparent activation energy (Ea). Interestingly, CH4 release from defined microbial cultures, from environmental samples and from wetland field sites all show similar Ea values around 100 kJ mol-1 indicating that CH4 production rates are limited by the methanogenic archaea rather than by hydrolysis of organic matter. Hence, the final rather than the initial step controls the methanogenic degradation of organic matter, which apparently is rarely in steady state.
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27
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Jiang JP, Liu X, Liao YF, Shan J, Zhu YP, Liu CH. Genomic insights into Aspergillus sydowii 29R-4-F02: unraveling adaptive mechanisms in subseafloor coal-bearing sediment environments. Front Microbiol 2023; 14:1216714. [PMID: 37455735 PMCID: PMC10339353 DOI: 10.3389/fmicb.2023.1216714] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/09/2023] [Indexed: 07/18/2023] Open
Abstract
Introduction Aspergillussydowii is an important filamentous fungus that inhabits diverse environments. However, investigations on the biology and genetics of A. sydowii in subseafloor sediments remain limited. Methods Here, we performed de novo sequencing and assembly of the A. sydowii 29R-4-F02 genome, an isolate obtained from approximately 2.4 km deep, 20-million-year-old coal-bearing sediments beneath the seafloor by employing the Nanopore sequencing platform. Results and Discussion The generated genome was 37.19 Mb with GC content of 50.05%. The final assembly consisted of 11 contigs with N50 of 4.6 Mb, encoding 12,488 putative genes. Notably, the subseafloor strain 29R-4-F02 showed a higher number of carbohydrate-active enzymes (CAZymes) and distinct genes related to vesicular fusion and autophagy compared to the terrestrial strain CBS593.65. Furthermore, 257 positively selected genes, including those involved in DNA repair and CAZymes were identified in subseafloor strain 29R-4-F02. These findings suggest that A. sydowii possesses a unique genetic repertoire enabling its survival in the extreme subseafloor environments over tens of millions of years.
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Affiliation(s)
- Jun-Peng Jiang
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Xuan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Yi-Fan Liao
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Jun Shan
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, China
| | - Yu-Ping Zhu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
| | - Chang-Hong Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, China
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28
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Noell SE, Hellweger FL, Temperton B, Giovannoni SJ. A Reduction of Transcriptional Regulation in Aquatic Oligotrophic Microorganisms Enhances Fitness in Nutrient-Poor Environments. Microbiol Mol Biol Rev 2023; 87:e0012422. [PMID: 36995249 PMCID: PMC10304753 DOI: 10.1128/mmbr.00124-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
In this review, we consider the regulatory strategies of aquatic oligotrophs, microbial cells that are adapted to thrive under low-nutrient concentrations in oceans, lakes, and other aquatic ecosystems. Many reports have concluded that oligotrophs use less transcriptional regulation than copiotrophic cells, which are adapted to high nutrient concentrations and are far more common subjects for laboratory investigations of regulation. It is theorized that oligotrophs have retained alternate mechanisms of regulation, such as riboswitches, that provide shorter response times and smaller amplitude responses and require fewer cellular resources. We examine the accumulated evidence for distinctive regulatory strategies in oligotrophs. We explore differences in the selective pressures copiotrophs and oligotrophs encounter and ask why, although evolutionary history gives copiotrophs and oligotrophs access to the same regulatory mechanisms, they might exhibit distinctly different patterns in how these mechanisms are used. We discuss the implications of these findings for understanding broad patterns in the evolution of microbial regulatory networks and their relationships to environmental niche and life history strategy. We ask whether these observations, which have emerged from a decade of increased investigation of the cell biology of oligotrophs, might be relevant to recent discoveries of many microbial cell lineages in nature that share with oligotrophs the property of reduced genome size.
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Affiliation(s)
- Stephen E. Noell
- Department of Microbiology, Oregon State University, Corvallis, Oregon, USA
| | | | - Ben Temperton
- School of Biosciences, University of Exeter, Exeter, United Kingdom
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29
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Gonzalez JM, Aranda B. Microbial Growth under Limiting Conditions-Future Perspectives. Microorganisms 2023; 11:1641. [PMID: 37512814 PMCID: PMC10383181 DOI: 10.3390/microorganisms11071641] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/02/2023] [Accepted: 06/20/2023] [Indexed: 07/30/2023] Open
Abstract
Microorganisms rule the functioning of our planet and each one of the individual macroscopic living creature. Nevertheless, microbial activity and growth status have always been challenging tasks to determine both in situ and in vivo. Microbial activity is generally related to growth, and the growth rate is a result of the availability of nutrients under adequate or adverse conditions faced by microbial cells in a changing environment. Most studies on microorganisms have been carried out under optimum or near-optimum growth conditions, but scarce information is available about microorganisms at slow-growing states (i.e., near-zero growth and maintenance metabolism). This study aims to better understand microorganisms under growth-limiting conditions. This is expected to provide new perspectives on the functions and relevance of the microbial world. This is because (i) microorganisms in nature frequently face conditions of severe growth limitation, (ii) microorganisms activate singular pathways (mostly genes remaining to be functionally annotated), resulting in a broad range of secondary metabolites, and (iii) the response of microorganisms to slow-growth conditions remains to be understood, including persistence strategies, gene expression, and cell differentiation both within clonal populations and due to the complexity of the environment.
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Affiliation(s)
- Juan M Gonzalez
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, IRNAS-CSIC, E-41012 Sevilla, Spain
| | - Beatriz Aranda
- Instituto de Recursos Naturales y Agrobiología de Sevilla, Consejo Superior de Investigaciones Científicas, IRNAS-CSIC, E-41012 Sevilla, Spain
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30
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Lopez-Fernandez M, Westmeijer G, Turner S, Broman E, Ståhle M, Bertilsson S, Dopson M. Thiobacillus as a key player for biofilm formation in oligotrophic groundwaters of the Fennoscandian Shield. NPJ Biofilms Microbiomes 2023; 9:41. [PMID: 37349512 DOI: 10.1038/s41522-023-00408-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 06/09/2023] [Indexed: 06/24/2023] Open
Abstract
Biofilm formation is a common adaptation for microbes in energy-limited conditions such as those prevalent in the vast deep terrestrial biosphere. However, due to the low biomass and the inaccessible nature of subsurface groundwaters, the microbial populations and genes involved in its formation are understudied. Here, a flow-cell system was designed to investigate biofilm formation under in situ conditions in two groundwaters of contrasting age and geochemistry at the Äspö Hard Rock Laboratory, Sweden. Metatranscriptomes showed Thiobacillus, Sideroxydans, and Desulforegula to be abundant and together accounted for 31% of the transcripts in the biofilm communities. Differential expression analysis highlighted Thiobacillus to have a principal role in biofilm formation in these oligotrophic groundwaters by being involved in relevant processes such as the formation of extracellular matrix, quorum sensing, and cell motility. The findings revealed an active biofilm community with sulfur cycling as a prominent mode of energy conservation in the deep biosphere.
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Affiliation(s)
- Margarita Lopez-Fernandez
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden.
- Department of Microbiology, Faculty of Sciences, University of Granada, Avenida Fuentenueva s/n, 18071, Granada, Spain.
| | - George Westmeijer
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
| | - Stephanie Turner
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Box 7026, 75007, Uppsala, Sweden
| | - Elias Broman
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Svante Arrhenius väg 20 A, 106 91, Stockholm, Sweden
| | - Magnus Ståhle
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
| | - Stefan Bertilsson
- Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Box 7050, SE75007, Uppsala, Sweden
| | - Mark Dopson
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Linnaeus University, Stuvaregatan 4, 392 31, Kalmar, Sweden
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31
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Lever MA, Alperin MJ, Hinrichs KU, Teske A. Zonation of the active methane-cycling community in deep subsurface sediments of the Peru trench. Front Microbiol 2023; 14:1192029. [PMID: 37250063 PMCID: PMC10213550 DOI: 10.3389/fmicb.2023.1192029] [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: 03/22/2023] [Accepted: 04/24/2023] [Indexed: 05/31/2023] Open
Abstract
The production and anaerobic oxidation of methane (AOM) by microorganisms is widespread in organic-rich deep subseafloor sediments. Yet, the organisms that carry out these processes remain largely unknown. Here we identify members of the methane-cycling microbial community in deep subsurface, hydrate-containing sediments of the Peru Trench by targeting functional genes of the alpha subunit of methyl coenzyme M reductase (mcrA). The mcrA profile reveals a distinct community zonation that partially matches the zonation of methane oxidizing and -producing activity inferred from sulfate and methane concentrations and carbon-isotopic compositions of methane and dissolved inorganic carbon (DIC). McrA appears absent from sulfate-rich sediments that are devoid of methane, but mcrA sequences belonging to putatively methane-oxidizing ANME-1a-b occur from the zone of methane oxidation to several meters into the methanogenesis zone. A sister group of ANME-1a-b, referred to as ANME-1d, and members of putatively aceticlastic Methanothrix (formerly Methanosaeta) occur throughout the remaining methanogenesis zone. Analyses of 16S rRNA and mcrA-mRNA indicate that the methane-cycling community is alive throughout (rRNA to 230 mbsf) and active in at least parts of the sediment column (mRNA at 44 mbsf). Carbon-isotopic depletions of methane relative to DIC (-80 to -86‰) suggest mostly methane production by CO2 reduction and thus seem at odds with the widespread detection of ANME-1 and Methanothrix. We explain this apparent contradiction based on recent insights into the metabolisms of both ANME-1 and Methanothricaceae, which indicate the potential for methanogenetic growth by CO2 reduction in both groups.
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Affiliation(s)
- Mark A. Lever
- Department of Marine Science, Marine Science Institute, University of Texas at Austin, Port Aransas, TX, United States
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Marc J. Alperin
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Kai-Uwe Hinrichs
- Organic Geochemistry Group, MARUM-Center for Marine Environmental Sciences and Department of Geosciences, University of Bremen, Bremen, Germany
| | - Andreas Teske
- Earth, Marine and Environmental Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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32
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Orsi WD. A rapid method for measuring ATP + ADP + AMP in marine sediment. Environ Microbiol 2023. [PMID: 36856556 DOI: 10.1111/1462-2920.16359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 02/26/2023] [Indexed: 03/02/2023]
Abstract
In this report, I describe a method for rapid measurement of total adenylate (ATP + ADP + AMP) in marine sediment samples for estimating microbial biomass. A simple 'boil and dilute' method is described here, whereby adding boiled MilliQ water to sediments increases the detection limit for ATP + ADP + AMP up to 100-fold. The lowered detection limit of this method enabled the detection ATP + ADP + AMP in relatively low-biomass sub-seafloor sediment cores with 104 16S rRNA gene copies per gram. Concentrations of ATP + ADP + AMP correlated with 16S rRNA gene concentrations from bacteria and archaea across six different sites that range in water depth from 1 to 6000 m indicating that the ATP + ADP + AMP method can be used as an additional biomass proxy. In deep sea microbial communities, the ratio of ATP + ADP + AMP concentrations to 16S rRNA genes >1 m below seafloor was significantly lower compared to communities in the upper 30 cm of sediment, which may be due to reduced cell sizes and or lower ATP + ADP + AMP concentrations per cell in the deep sea sub-seafloor biosphere. The boil and dilute method for ATP + ADP + AMP is demonstrated here to have a detection limit sufficient for measuring low biomass communities from deep sea sub-seafloor cores. The method can be applied to frozen samples, enabling measurements of ATP + ADP + AMP from frozen sediment cores stored in core repositories from past and future international drilling campaigns.
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Affiliation(s)
- William D Orsi
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, Munich, Germany.,GeoBio-CenterLMU, Ludwig-Maximilians-Universität München, Munich, Germany
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33
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Bell E, Rattray JE, Sloan K, Sherry A, Pilloni G, Hubert CRJ. Hyperthermophilic endospores germinate and metabolize organic carbon in sediments heated to 80°C. Environ Microbiol 2022; 24:5534-5545. [PMID: 36100999 PMCID: PMC9826295 DOI: 10.1111/1462-2920.16167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 08/10/2022] [Indexed: 01/11/2023]
Abstract
Cold surface sediments host a seedbank of functionally diverse thermophilic bacteria. These thermophiles are present as endospores, which are widely dispersed in aquatic environments. Here, we investigated the functional potential of endospore populations in cold surface sediments heated to 80°C. Microbial production of acetate was observed at 80°C and could be enhanced by supplying additional organic carbon substrates. Comparison of 16S rRNA gene amplicon libraries from 80°C enrichments to sediments heated to lower temperatures (50-70°C) showed that temperature selects for distinct populations of endospore-forming bacteria. Whereas sulfate-reducing thermophiles were enriched in 50-70°C incubations, 80°C exceeds their thermal tolerance and selects for hyperthermophilic organotrophic bacteria that are similarly detected in amplicon libraries from sediments heated to 90°C. Genome-resolved metagenomics revealed novel carbon cycling members of Symbiobacteriales, Thermosediminibacteraceae, Thermanaeromonas and Calditerricola with the genomic potential for the degradation of carbohydrates, sugars, amino acids and nucleotides. Endospores of thermophilic bacteria are deposited on seabed sediments worldwide where they remain dormant as they are buried in the accumulating sediments. Our results suggest that endospore populations could be activated by temperature increases encountered during burial and show the potential for organotrophic metabolic activity contributing to acetate generation in deep hot sediments.
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Affiliation(s)
- Emma Bell
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada,School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Jayne E. Rattray
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
| | - Kathryn Sloan
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada
| | - Angela Sherry
- Hub for Biotechnology in the Built Environment, Department of Applied SciencesNorthumbria UniversityNewcastle upon TyneUK
| | - Giovanni Pilloni
- ExxonMobil Technology and Engineering CompanyAnnandaleNew JerseyUSA
| | - Casey R. J. Hubert
- Geomicrobiology Group, Department of Biological SciencesUniversity of CalgaryCalgaryAlbertaCanada,School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneUK
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El Moussaoui T. Studies on the activated sludge process crucial parameters controlling olive mill wastewater treatment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156455. [PMID: 35671855 DOI: 10.1016/j.scitotenv.2022.156455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 05/22/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Olive mill wastewater (OMW) represents a severe environmental problem for Mediterranean producer countries. The release of OMW, in urban areas, in public sewerage system constitute a serious problem for wastewater treatment plant (WWTP) based on biological processes. This study delivers a critical and a comprehensive analysis on activated sludge biomass and process crucial parameters involved in the treatment of OMW. Principal component analysis (PCA) has been applied to master the relationship between activated sludge physiological state and process performances stability. After the acclimation step with easily biodegradable synthetic substrate (SS), increased OMW F/M mass ratio has been applied to the bioreactor (60 L) of experimental pilot-scale AS system in respect to its nominal capacity. PCA highlight two main periods, a first stressful period presented by G1[T0-T10%], G2[T20%-T30%] and G3[T40%-T50%] AS microbial communities were very sensitive to substrate changes. This was manifested by low metabolic activity (OUR, SOUR and SOURinh), important drop in AS microbial communities content, an increase in soluble microbial products (SMP), a fluctuate performances in COD and total phenols abatements as well as in flocks settleability (SVI). Afterwards, a reestablishment second period presented by G4[T60%-T100%] of key process parameters and AS biomass efficiency indices is reached. This period characterized by the substantial content, resistance and adaption of AS microbial communities to OMW as F/M. Succeeding optimal AS biomass and process performances, under stressful conditions, requires a precise knowledge and control of decisive parameters involved in OMW treatment and this study could be an efficient practical approach in case of OMW also for further toxic compounds.
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Affiliation(s)
- Tawfik El Moussaoui
- Resources Valorization, Environment and Sustainable Development Research Team (RVESD), Department of Mines, Mines School of Rabat, Ave Hadj Ahmed Cherkaoui - BP 753, Agdal, Rabat, Morocco; Laboratory of Water, Biodiversity and Climate Change, Faculty of Sciences Semlalia, Cadi Ayyad University, BP- 2390, 40,000 Marrakech, Morocco.
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35
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Abstract
Since Jacques Monod's foundational work in the 1940s, investigators studying bacterial physiology have largely (but not exclusively) focused on the exponential phase of bacterial cultures, which is characterized by rapid growth and high biosynthesis activity in the presence of excess nutrients. However, this is not the predominant state of bacterial life. In nature, most bacteria experience nutrient limitation most of the time. In fact, investigators even prior to Monod had identified other aspects of bacterial growth, including what is now known as the stationary phase, when nutrients become limiting. This review will discuss how bacteria transition to growth arrest in response to nutrient limitation through changes in transcription, translation, and metabolism. We will then examine how these changes facilitate survival during potentially extended periods of nutrient limitation, with particular attention to the metabolic strategies that underpin bacterial longevity in this state.
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Affiliation(s)
- Jonathan Dworkin
- Department of Microbiology and Immunology, College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Caroline S Harwood
- Department of Microbiology, University of Washington, Seattle, Washington, USA;
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36
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Kellom M, Pagliara S, Richards TA, Santoro AE. Exaggerated trans-membrane charge of ammonium transporters in nutrient-poor marine environments. Open Biol 2022; 12:220041. [PMID: 35857930 PMCID: PMC9277239 DOI: 10.1098/rsob.220041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Transporter proteins are a vital interface between cells and their environment. In nutrient-limited environments, microbes with transporters that are effective at bringing substrates into their cells will gain a competitive advantage over variants with reduced transport function. Microbial ammonium transporters (Amt) bring ammonium into the cytoplasm from the surrounding periplasm space, but diagnosing Amt adaptations to low nutrient environments solely from sequence data has been elusive. Here, we report altered Amt sequence amino acid distribution from deep marine samples compared to variants sampled from shallow water in two important microbial lineages of the marine water column community-Marine Group I Archaea (Thermoproteota) and the uncultivated gammaproteobacterial lineage SAR86. This pattern indicates an evolutionary pressure towards an increasing dipole in Amt for these clades in deep ocean environments and is predicted to generate stronger electric fields facilitating ammonium acquisition. This pattern of increasing dipole charge with depth was not observed in lineages capable of accessing alternative nitrogen sources, including the abundant alphaproteobacterial clade SAR11. We speculate that competition for ammonium in the deep ocean drives transporter sequence evolution. The low concentration of ammonium in the deep ocean is therefore likely due to rapid uptake by Amts concurrent with decreasing nutrient flux.
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Affiliation(s)
- Matthew Kellom
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Stefano Pagliara
- Living Systems Institute and Biosciences, University of Exeter, Exeter, Devon EX4 4QD, UK
| | - Thomas A. Richards
- Department of Zoology, University of Oxford, 11a Mansfield Road, Oxford OX1 3SZ, UK
| | - Alyson E. Santoro
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
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37
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Liu X, Huang X, Chu C, Xu H, Wang L, Xue Y, Arifeen Muhammad ZU, Inagaki F, Liu C. Genome, genetic evolution, and environmental adaptation mechanisms of Schizophyllum commune in deep subseafloor coal-bearing sediments. iScience 2022; 25:104417. [PMID: 35663011 PMCID: PMC9156946 DOI: 10.1016/j.isci.2022.104417] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/30/2022] [Accepted: 05/12/2022] [Indexed: 12/15/2022] Open
Abstract
To understand the genomic evolution and adaptation strategies of fungi to subseafloor sedimentary environments, we de novo assembled the genome of Schizophyllum commune strain 20R-7-F01 isolated from ∼2.0 km-deep, ∼20-millionyearsago (Mya) coal-bearing sediments. Phylogenomics study revealed a differentiation time of 28-73 Mya between this strain and the terrestrial type-strain H4-8, in line with sediment age records. Comparative genome analyses showed that FunK1 protein kinase, NmrA family, and transposons in this strain are significantly expanded, possibly linking to the environmental adaptation and persistence in sediment for over millions of years. Re-sequencing study of 14 S. commune strains sampled from different habitats revealed that subseafloor strains have much lower nucleotide diversity, substitution rate, and homologous recombination rate than other strains, reflecting that the growth and/or reproduction of subseafloor strains are extremely slow. Our data provide new insights into the adaptation and long-term survival of the fungi in the subseafloor sedimentary biosphere.
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Affiliation(s)
- Xuan Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | - Xin Huang
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | - Chen Chu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | - Hui Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | - Long Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | - Yarong Xue
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
| | | | - Fumio Inagaki
- Mantle Drilling Promotion Office, Institute for Marine-Earth Exploration and Engineering (MarE3), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama 236-0001, Japan
- Department of Earth Sciences, Graduate School of Science, Tohoku University, Sendai 980-8574, Japan
| | - Changhong Liu
- State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing 210023, China
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38
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Chakrawal A, Calabrese S, Herrmann AM, Manzoni S. Interacting Bioenergetic and Stoichiometric Controls on Microbial Growth. Front Microbiol 2022; 13:859063. [PMID: 35656001 PMCID: PMC9152356 DOI: 10.3389/fmicb.2022.859063] [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: 01/20/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Microorganisms function as open systems that exchange matter and energy with their surrounding environment. Even though mass (carbon and nutrients) and energy exchanges are tightly linked, there is a lack of integrated approaches that combine these fluxes and explore how they jointly impact microbial growth. Such links are essential to predicting how the growth rate of microorganisms varies, especially when the stoichiometry of carbon- (C) and nitrogen (N)-uptake is not balanced. Here, we present a theoretical framework to quantify the microbial growth rate for conditions of C-, N-, and energy-(co-) limitations. We use this framework to show how the C:N ratio and the degree of reduction of the organic matter (OM), which is also the electron donor, availability of electron acceptors (EAs), and the different sources of N together control the microbial growth rate under C, nutrient, and energy-limited conditions. We show that the growth rate peaks at intermediate values of the degree of reduction of OM under oxic and C-limited conditions, but not under N-limited conditions. Under oxic conditions and with N-poor OM, the growth rate is higher when the inorganic N (NInorg)-source is ammonium compared to nitrate due to the additional energetic cost involved in nitrate reduction. Under anoxic conditions, when nitrate is both EA and NInorg-source, the growth rates of denitrifiers and microbes performing the dissimilatory nitrate reduction to ammonia (DNRA) are determined by both OM degree of reduction and nitrate-availability. Consistent with the data, DNRA is predicted to foster growth under extreme nitrate-limitation and with a reduced OM, whereas denitrifiers are favored as nitrate becomes more available and in the presence of oxidized OM. Furthermore, the growth rate is reduced when catabolism is coupled to low energy yielding EAs (e.g., sulfate) because of the low carbon use efficiency (CUE). However, the low CUE also decreases the nutrient demand for growth, thereby reducing N-limitation. We conclude that bioenergetics provides a useful conceptual framework for explaining growth rates under different metabolisms and multiple resource-limitations.
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Affiliation(s)
- Arjun Chakrawal
- Department of Physical Geography, Stockholm University, Stockholm, Sweden.,Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | - Salvatore Calabrese
- Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX, United States
| | - Anke M Herrmann
- Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Stefano Manzoni
- Department of Physical Geography, Stockholm University, Stockholm, Sweden.,Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
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39
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Karwautz C, Zhou Y, Kerros ME, Weinbauer MG, Griebler C. Bottom-Up Control of the Groundwater Microbial Food-Web in an Alpine Aquifer. Front Ecol Evol 2022. [DOI: 10.3389/fevo.2022.854228] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Groundwater ecosystems are typically poor in organic carbon and productivity sustaining a low standing stock of microbial biomass. In consequence, microbial food webs in oligotrophic groundwater are hypothesized to be bottom-up controlled. To date, quantitative information on groundwater microbial communities, food web interactions, and carbon flow is relatively lacking in comparison to that of surface waters. Studying a shallow, porous alpine aquifer we collected data on the numbers of prokaryotes, virus-like particles and heterotrophic nanoflagellates (HNFs), the concentration of dissolved (DOC) and assimilable organic carbon (AOC), bacterial carbon production (BCP), and physical-chemical conditions for a 1 year hydrological cycle. The potential effects of protozoan grazing and viral lysis onto the prokaryotic biomass was tested. Flow of organic carbon through the microbial food web was estimated based on data from the literature. The abundance of prokaryotes in groundwater was low with 6.1 ± 6.9 × 104 cells mL–1, seasonally influenced by the hydrological dynamics, with higher densities coinciding with a lower groundwater table. Overall, the variability in cell numbers was moderate, and so it was for HNFs (179 ± 103 HNFs mL–1) and virus-like particles (9.6 ± 5.7 × 105 VLPs mL–1). The virus to prokaryotes and prokaryote to HNF ratios ranged between 2–230 and 33–2,084, respectively. We found no evidence for a viral control of prokaryotic biomass, and the biomass of HNFs being bottom-up controlled. First estimations point at carbon use efficiencies of 0.2–4.2% with prokaryotic production, and carbon consumed and recycled by HNFs and phages to be of minor importance. This first groundwater microbial food web analysis strongly hints at a bottom-up control on productivity and standing stock in oligotrophic groundwater ecosystems. However, direct measurement of protozoan grazing and phage mediated lysis rates of prokaryotic cells are urgently needed to deepen our mechanistic understanding. The effect of microbial diversity on the population dynamics still needs to be addressed.
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40
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Zhou Y, Zhao C, He C, Li P, Wang Y, Pang Y, Shi Q, He D. Characterization of dissolved organic matter processing between surface sediment porewater and overlying bottom water in the Yangtze River Estuary. WATER RESEARCH 2022; 215:118260. [PMID: 35294911 DOI: 10.1016/j.watres.2022.118260] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 03/03/2022] [Accepted: 03/05/2022] [Indexed: 06/14/2023]
Abstract
Dissolved organic matter (DOM) exchange in the sediment-water interface of estuaries is essential for the global elemental cycle. To clarify the interface DOM processing, this study applies optical techniques and ultrahigh-resolution mass spectrometry to assess DOM composition of surface sediment porewater and bottom (overlying) water across the Yangtze River Estuary (YRE). Results suggested that DOM exchange in the sediment-water interface mainly followed from sediment porewater to bottom water driven by a significant dissolved organic carbon concentration gradient and hydrodynamic force. We also characterized two porewater DOM sources, including microbial production and byproducts of processed sediments. High microbial activities resulted in the enrichment of protein-like fluorescent components and N-bearing compounds in porewater, potentially decreasing the oxygen concentration of bottom water due to the high lability. And the deamination of N-bearing compounds in the sediment-water interface could likely serve as a N-bearing nutrient source to bottom water. Moreover, due to sediment-specific features in different areas driven by hydrologic sorting and local phytoplankton supply, porewater DOM of muddy areas accumulated more aromatic substances from the degradation of terrestrial organic matter. The release and oxic transformation of oxygen-deficient aromatic compounds could contribute to the refractory carbon pool of estuarine water (carboxyl-rich alicyclic molecules, CRAM), modulating the quality of organic carbon mobilized from the land to the coastal ocean. Considering strong hydrodynamic force in numerous estuaries worldwide, DOM exchange and processing at the sediment-water interface has a meaningful influence on the biogeochemistry of estuarine water columns, which warrants further studies.
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Affiliation(s)
- Yuping Zhou
- School of Environmental and Municipal Engineering, Qingdao University of Technology, Qingdao 266525, China; Organic Geochemistry Unit, Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chen Zhao
- Organic Geochemistry Unit, Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China
| | - Chen He
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Changping District, Beijing 102249, China
| | - Penghui Li
- School of Marine Sciences, Sun Yat-sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China
| | - Yuntao Wang
- State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China
| | - Yu Pang
- Organic Geochemistry Unit, Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China
| | - Quan Shi
- State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Changping District, Beijing 102249, China
| | - Ding He
- Department of Ocean Science and Hong Kong Branch of the Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), The Hong Kong University of Science and Technology, Hong Kong SAR, China; Organic Geochemistry Unit, Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China; State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, China.
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41
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Gropp J, Jin Q, Halevy I. Controls on the isotopic composition of microbial methane. SCIENCE ADVANCES 2022; 8:eabm5713. [PMID: 35385305 PMCID: PMC8985922 DOI: 10.1126/sciadv.abm5713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 02/15/2022] [Indexed: 06/14/2023]
Abstract
Microbial methane production (methanogenesis) is responsible for more than half of the annual emissions of this major greenhouse gas to the atmosphere. Although the stable isotopic composition of methane is often used to characterize its sources and sinks, strictly empirical descriptions of the isotopic signature of methanogenesis currently limit these attempts. We developed a metabolic-isotopic model of methanogenesis by carbon dioxide reduction, which predicts carbon and hydrogen isotopic fractionations, and clumped isotopologue distributions, as functions of the cell's environment. We mechanistically explain multiple isotopic patterns in laboratory and natural settings and show that these patterns constrain the in situ energetics of methanogenesis. Combining our model with data from environments in which methanogenic activity is energy-limited, we provide predictions for the biomass-specific methanogenesis rates and the associated isotopic effects.
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Affiliation(s)
- Jonathan Gropp
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Qusheng Jin
- Department of Earth Sciences, University of Oregon, Eugene, OR, USA
| | - Itay Halevy
- Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
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42
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Galkina KV, Zubareva VM, Kashko ND, Lapashina AS, Markova OV, Feniouk BA, Knorre DA. Heterogeneity of Starved Yeast Cells in IF1 Levels Suggests the Role of This Protein in vivo. Front Microbiol 2022; 13:816622. [PMID: 35401495 PMCID: PMC8984185 DOI: 10.3389/fmicb.2022.816622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/01/2022] [Indexed: 11/13/2022] Open
Abstract
In mitochondria, a small protein IF1 suppresses the hydrolytic activity of ATP synthase and presumably prevents excessive ATP hydrolysis under conditions of energy deprivation. In yeast Saccharomyces cerevisiae, IF1 homologs are encoded by two paralogous genes: INH1 and STF1. INH1 expression is known to aggravate the deleterious effects of mitochondrial DNA (mtDNA) depletion. Surprisingly, no beneficial effects of INH1 and STF1 were documented for yeast so far, and the functions of INH1 and STF1 in wild type cells are unclear. Here, we put forward a hypothesis that INH1 and STF1 bring advantage during the fast start of proliferation after reentry into exponential growth from post-diauxic or stationary phases. We found that yeast cells increase the concentration of both proteins in the post-diauxic phase. Post-diauxic phase yeast cells formed two subpopulations distinct in Inh1p and Stf1p concentrations. Upon exit from the post-diauxic phase cells with high level of Inh1-GFP started growing earlier than cells devoid of Inh1-GFP. However, double deletion of INH1 and STF1 did not increase the lag period necessary for stationary phase yeast cells to start growing after reinoculation into the fresh medium. These results point to a redundancy of the mechanisms preventing uncontrolled ATP hydrolysis during energy deprivation.
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Affiliation(s)
- Kseniia V. Galkina
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Valeria M. Zubareva
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Nataliia D. Kashko
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Anna S. Lapashina
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
- Department of Biological Chemistry, Sechenov First Moscow State Medical University, Moscow, Russia
| | - Olga V. Markova
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Boris A. Feniouk
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
| | - Dmitry A. Knorre
- A. N. Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, Russia
- *Correspondence: Dmitry A. Knorre,
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43
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Chen SC, Ji J, Popp D, Jaekel U, Richnow HH, Sievert SM, Musat F. Genome and proteome analyses show the gaseous alkane degrader Desulfosarcina sp. strain BuS5 as an extreme metabolic specialist. Environ Microbiol 2022; 24:1964-1976. [PMID: 35257474 DOI: 10.1111/1462-2920.15956] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 02/23/2022] [Indexed: 11/30/2022]
Abstract
The metabolic potential of the sulfate-reducing bacterium Desulfosarcina sp. strain BuS5, currently the only pure culture able to oxidize the volatile alkanes propane and butane without oxygen, was investigated via genomics, proteomics and physiology assays. Complete genome sequencing revealed that strain BuS5 encodes a single alkyl-succinate synthase, an enzyme which apparently initiates oxidation of both propane and butane. The formed alkyl-succinates are oxidized to CO2 via beta oxidation and the oxidative Wood-Ljungdahl pathways as shown by proteogenomics analyses. Strain BuS5 conserves energy via the canonical sulfate reduction pathway and electron bifurcation. An ability to utilize long-chain fatty acids, mannose and oligopeptides, suggested by automated annotation pipelines, was not supported by physiology assays and in-depth analyses of the corresponding genetic systems. Consistently, comparative genomics revealed a streamlined BuS5 genome with a remarkable paucity of catabolic modules. These results establish strain BuS5 as an exceptional metabolic specialist, able to grow only with propane and butane, for which we propose the name Desulfosarcina aeriophaga BuS5. This highly restrictive lifestyle, most likely the result of habitat-driven evolutionary gene loss, may provide D. aeriophaga BuS5 a competitive edge in sediments impacted by natural gas seeps. Etymology: Desulfosarcina aeriophaga, aério (Greek): gas; phágos (Greek): eater; D. aeriophaga: a gas eating or gas feeding Desulfosarcina.
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Affiliation(s)
- Song-Can Chen
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Jiaheng Ji
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Denny Popp
- Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | | | - Hans-Hermann Richnow
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Stefan M Sievert
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA, 02543, USA
| | - Florin Musat
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.,Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, Cluj-Napoca, Romania
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44
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Beulig F, Schubert F, Adhikari RR, Glombitza C, Heuer VB, Hinrichs KU, Homola KL, Inagaki F, Jørgensen BB, Kallmeyer J, Krause SJE, Morono Y, Sauvage J, Spivack AJ, Treude T. Rapid metabolism fosters microbial survival in the deep, hot subseafloor biosphere. Nat Commun 2022; 13:312. [PMID: 35078973 PMCID: PMC8789916 DOI: 10.1038/s41467-021-27802-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 12/10/2021] [Indexed: 11/25/2022] Open
Abstract
A fourth of the global seabed sediment volume is buried at depths where temperatures exceed 80 °C, a previously proposed thermal barrier for life in the subsurface. Here, we demonstrate, utilizing an extensive suite of radiotracer experiments, the prevalence of active methanogenic and sulfate-reducing populations in deeply buried marine sediment from the Nankai Trough subduction zone, heated to extreme temperature (up to ~120 °C). The small microbial community subsisted with high potential cell-specific rates of energy metabolism, which approach the rates of active surface sediments and laboratory cultures. Our discovery is in stark contrast to the extremely low metabolic rates otherwise observed in the deep subseafloor. As cells appear to invest most of their energy to repair thermal cell damage in the hot sediment, they are forced to balance delicately between subsistence near the upper temperature limit for life and a rich supply of substrates and energy from thermally driven reactions of the sedimentary organic matter. In the deep sedimentary biosphere, 80 °C has been proposed as an upper thermal barrier for life. Using a suite of radiotracer experiments, this study reports active methanogenic and sulfate-reducing microbial populations with high cell-specific metabolic rates in deeply buried marine sediments from the Nankai Trough subduction zone, which reach temperatures up to 120 °C.
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45
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Favreau C, Tribondeau A, Marugan M, Guyot F, Alpha-Bazin B, Marie A, Puppo R, Dufour T, Huguet A, Zirah S, Kish A. Molecular acclimation of Halobacterium salinarum to halite brine inclusions. Front Microbiol 2022; 13:1075274. [PMID: 36875534 PMCID: PMC9976938 DOI: 10.3389/fmicb.2022.1075274] [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: 10/20/2022] [Accepted: 12/22/2022] [Indexed: 01/27/2023] Open
Abstract
Halophilic microorganisms have long been known to survive within the brine inclusions of salt crystals, as evidenced by the change in color for salt crystals containing pigmented halophiles. However, the molecular mechanisms allowing this survival has remained an open question for decades. While protocols for the surface sterilization of halite (NaCl) have enabled isolation of cells and DNA from within halite brine inclusions, "-omics" based approaches have faced two main technical challenges: (1) removal of all contaminating organic biomolecules (including proteins) from halite surfaces, and (2) performing selective biomolecule extractions directly from cells contained within halite brine inclusions with sufficient speed to avoid modifications in gene expression during extraction. In this study, we tested different methods to resolve these two technical challenges. Following this method development, we then applied the optimized methods to perform the first examination of the early acclimation of a model haloarchaeon (Halobacterium salinarum NRC-1) to halite brine inclusions. Examinations of the proteome of Halobacterium cells two months post-evaporation revealed a high degree of similarity with stationary phase liquid cultures, but with a sharp down-regulation of ribosomal proteins. While proteins for central metabolism were part of the shared proteome between liquid cultures and halite brine inclusions, proteins involved in cell mobility (archaellum, gas vesicles) were either absent or less abundant in halite samples. Proteins unique to cells within brine inclusions included transporters, suggesting modified interactions between cells and the surrounding brine inclusion microenvironment. The methods and hypotheses presented here enable future studies of the survival of halophiles in both culture model and natural halite systems.
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Affiliation(s)
- Charly Favreau
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
| | - Alicia Tribondeau
- Unité Physiologie Moléculaire et Adaptation (PhyMA), MNHN, CNRS, Paris, France
| | - Marie Marugan
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
| | - François Guyot
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), MNHN, Sorbonne Université, CNRS, IRD, Paris, France
| | - Beatrice Alpha-Bazin
- Département Médicaments et Technologies pour la Santé (DMTS), Université Paris-Saclay, CEA, INRAE, SPI, Bagnols-sur-Cèze, France
| | - Arul Marie
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
| | - Remy Puppo
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
| | - Thierry Dufour
- Laboratoire de Physique des Plasma (LPP), Sorbonne Université, CNRS, École Polytechnique, Université Paris-Sud, Observatoire de Paris, Paris, France
| | - Arnaud Huguet
- Unité Milieux Environnementaux Transferts et Interactions dans les hydrosystèmes et les Sols (METIS), Sorbonne Université, CNRS, EPHE, PSL, Paris, France
| | - Séverine Zirah
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
| | - Adrienne Kish
- Unité Molécules de Communication et Adaptation des Microorganismes (MCAM), Muséum National d'Histoire Naturelle (MNHN), CNRS, Paris, France
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Response to substrate limitation by a marine sulfate-reducing bacterium. THE ISME JOURNAL 2022; 16:200-210. [PMID: 34285365 PMCID: PMC8692349 DOI: 10.1038/s41396-021-01061-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/04/2021] [Accepted: 07/06/2021] [Indexed: 02/07/2023]
Abstract
Sulfate-reducing microorganisms (SRM) in subsurface sediments live under constant substrate and energy limitation, yet little is known about how they adapt to this mode of life. We combined controlled chemostat cultivation and transcriptomics to examine how the marine sulfate reducer, Desulfobacterium autotrophicum, copes with substrate (sulfate or lactate) limitation. The half-saturation uptake constant (Km) for lactate was 1.2 µM, which is the first value reported for a marine SRM, while the Km for sulfate was 3 µM. The measured residual lactate concentration in our experiments matched values observed in situ in marine sediments, supporting a key role of SRM in the control of lactate concentrations. Lactate limitation resulted in complete lactate oxidation via the Wood-Ljungdahl pathway and differential overexpression of genes involved in uptake and metabolism of amino acids as an alternative carbon source. D. autotrophicum switched to incomplete lactate oxidation, rerouting carbon metabolism in response to sulfate limitation. The estimated free energy was significantly lower during sulfate limitation (-28 to -33 kJ mol-1 sulfate), suggesting that the observed metabolic switch is under thermodynamic control. Furthermore, we detected the upregulation of putative sulfate transporters involved in either high or low affinity uptake in response to low or high sulfate concentration.
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Wisnoski NI, Shoemaker LG. Seed banks alter metacommunity diversity: The interactive effects of competition, dispersal and dormancy. Ecol Lett 2021; 25:740-753. [PMID: 34965013 DOI: 10.1111/ele.13944] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 11/10/2021] [Accepted: 11/24/2021] [Indexed: 01/12/2023]
Abstract
Dispersal and dormancy are two common strategies allowing for species persistence and the maintenance of biodiversity in variable environments. However, theory and empirical tests of spatial diversity patterns tend to examine either mechanism in isolation. Here, we developed a stochastic, spatially explicit metacommunity model incorporating seed banks with varying germination and survival rates. We found that dormancy and dispersal had interactive, nonlinear effects on the maintenance and distribution of metacommunity diversity. Seed banks promoted local diversity when seed survival was high and maintained regional diversity through interactions with dispersal. The benefits of seed banks for regional diversity were largest when dispersal was high or intermediate, depending on whether local competition was equal or stabilising. Our study shows that classic predictions for how dispersal affects metacommunity diversity can be strongly influenced by dormancy. Together, these results emphasise the need to consider both temporal and spatial processes when predicting multi-scale patterns of diversity.
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Affiliation(s)
- Nathan I Wisnoski
- Wyoming Geographic Information Science Center, University of Wyoming, Laramie, Wyoming, USA
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Daisley BA, Koenig D, Engelbrecht K, Doney L, Hards K, Al KF, Reid G, Burton JP. Emerging connections between gut microbiome bioenergetics and chronic metabolic diseases. Cell Rep 2021; 37:110087. [PMID: 34879270 DOI: 10.1016/j.celrep.2021.110087] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 11/03/2021] [Accepted: 11/10/2021] [Indexed: 12/25/2022] Open
Abstract
The conventional viewpoint of single-celled microbial metabolism fails to adequately depict energy flow at the systems level in host-adapted microbial communities. Emerging paradigms instead support that distinct microbiomes develop interconnected and interdependent electron transport chains that rely on cooperative production and sharing of bioenergetic machinery (i.e., directly involved in generating ATP) in the extracellular space. These communal resources represent an important subset of the microbial metabolome, designated here as the "pantryome" (i.e., pantry or external storage compartment), that critically supports microbiome function and can exert multifunctional effects on host physiology. We review these interactions as they relate to human health by detailing the genomic-based sharing potential of gut-derived bacterial and archaeal reference strains. Aromatic amino acids, metabolic cofactors (B vitamins), menaquinones (vitamin K2), hemes, and short-chain fatty acids (with specific emphasis on acetate as a central regulator of symbiosis) are discussed in depth regarding their role in microbiome-related metabolic diseases.
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Affiliation(s)
- Brendan A Daisley
- Department of Microbiology & Immunology, The University of Western Ontario, London, ON N6A 5C1, Canada; Canadian Centre for Human Microbiome and Probiotics Research, London, ON N6A 4V2, Canada
| | - David Koenig
- Kimberly Clark Corporation, Global Research and Engineering-Life Science, Neenah, WI, USA
| | - Kathleen Engelbrecht
- Kimberly Clark Corporation, Global Research and Engineering-Life Science, Neenah, WI, USA
| | - Liz Doney
- Kimberly Clark Corporation, Global Research and Engineering-Life Science, Neenah, WI, USA
| | - Kiel Hards
- Department of Microbiology and Immunology, University of Otago, Dunedin, Otago, New Zealand
| | - Kait F Al
- Department of Microbiology & Immunology, The University of Western Ontario, London, ON N6A 5C1, Canada; Canadian Centre for Human Microbiome and Probiotics Research, London, ON N6A 4V2, Canada
| | - Gregor Reid
- Department of Microbiology & Immunology, The University of Western Ontario, London, ON N6A 5C1, Canada; Canadian Centre for Human Microbiome and Probiotics Research, London, ON N6A 4V2, Canada; Department of Surgery, Division of Urology, Schulich School of Medicine, London, ON N6A 5C1, Canada
| | - Jeremy P Burton
- Department of Microbiology & Immunology, The University of Western Ontario, London, ON N6A 5C1, Canada; Canadian Centre for Human Microbiome and Probiotics Research, London, ON N6A 4V2, Canada; Department of Surgery, Division of Urology, Schulich School of Medicine, London, ON N6A 5C1, Canada.
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49
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Okabe S, Kamigaito A, Kobayashi K. Maintenance power requirements of anammox bacteria "Candidatus Brocadia sinica" and "Candidatus Scalindua sp.". THE ISME JOURNAL 2021; 15:3566-3575. [PMID: 34145389 PMCID: PMC8629980 DOI: 10.1038/s41396-021-01031-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 02/05/2023]
Abstract
Little is known about the cell physiology of anammox bacteria growing at extremely low growth rates. Here, "Candidatus Brocadia sinica" and "Candidatus Scalindua sp." were grown in continuous anaerobic membrane bioreactors (MBRs) with complete biomass retention to determine maintenance energy (i.e., power) requirements at near-zero growth rates. After prolonged retentostat cultivations, the specific growth rates (μ) of "Ca. B. sinica" and "Ca. Scalindua sp." decreased to 0.000023 h-1 (doubling time of 1255 days) and 0.000157 h-1 (184 days), respectively. Under these near-zero growth conditions, substrate was continuously utilized to meet maintenance energy demands (me) of 6.7 ± 0.7 and 4.3 ± 0.7 kJ mole of biomass-C-1 h-1 for "Ca. B. sinica" and "Ca. Scalindua sp.", which accorded with the theoretically predicted values of all anaerobic microorganisms (9.7 and 4.4 kJ mole of biomass-C-1 h-1at 37 °C and 28 °C, respectively). These me values correspond to 13.4 × 10-15 and 8.6 × 10-15 watts cell-1 for "Ca. B. sinica" and "Ca. Scalindua sp.", which were five orders of magnitude higher than the basal power limit for natural settings (1.9 × 10-19 watts cells-1). Furthermore, the minimum substrate concentrations required for growth (Smin) were calculated to be 3.69 ± 0.21 and 0.09 ± 0.05 μM NO2- for "Ca. B. sinica" and "Ca. Scalindua sp.", respectively. These results match the evidence that "Ca. Scalindua sp." with lower maintenance power requirement and Smin are better adapted to energy-limited natural environments than "Ca. B. sinica", suggesting the importance of these parameters on ecological niche differentiation in natural environments.
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Affiliation(s)
- Satoshi Okabe
- grid.39158.360000 0001 2173 7691Department of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido, 060-8628 Japan
| | - Atsushi Kamigaito
- grid.39158.360000 0001 2173 7691Department of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido, 060-8628 Japan
| | - Kanae Kobayashi
- grid.39158.360000 0001 2173 7691Department of Environmental Engineering, Faculty of Engineering, Hokkaido University, North 13, West 8, Sapporo, Hokkaido, 060-8628 Japan
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50
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Microbial community structure in hadal sediments: high similarity along trench axes and strong changes along redox gradients. THE ISME JOURNAL 2021; 15:3455-3467. [PMID: 34103697 PMCID: PMC8629969 DOI: 10.1038/s41396-021-01021-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 05/11/2021] [Accepted: 05/20/2021] [Indexed: 02/05/2023]
Abstract
Hadal trench sediments are hotspots of biogeochemical activity in the deep sea, but the biogeochemical and ecological factors that shape benthic hadal microbial communities remain unknown. Here, we sampled ten hadal sites from two trench regions with a vertical resolution of down to 1 cm. We sequenced 16S rRNA gene amplicons using universal and archaea-specific primer sets and compared the results to biogeochemical parameters. Despite bathymetric and depositional heterogeneity we found a high similarity of microbial communities within each of the two trench axes, while composition at the phylum level varied strongly with sediment depth in conjunction with the redox stratification into oxic, nitrogenous, and ferruginous zones. As a result, communities of a given sediment horizon were more similar to each other across a distance of hundreds of kilometers within each trench, than to those of adjacent horizons from the same sites separated only by centimeters. Total organic carbon content statistically only explained a small part of the variation within and between trenches, and did not explain the community differences observed between the hadal and adjacent shallower sites. Anaerobic taxa increased in abundance at the top of the ferruginous zone, seeded by organisms deposited at the sediment surface and surviving burial through the upper redox zones. While an influence of other potential factors such as geographic isolation, hydrostatic pressure, and non-steady state depositional regimes could not be discerned, redox stratification and diagenesis appear to be the main selective forces that structure community composition in hadal sediments.
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