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Cai L, Li H, Deng J, Zhou R, Zeng Q. Biological interactions with Prochlorococcus: implications for the marine carbon cycle. Trends Microbiol 2024; 32:280-291. [PMID: 37722980 DOI: 10.1016/j.tim.2023.08.011] [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: 04/29/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/20/2023]
Abstract
The unicellular picocyanobacterium Prochlorococcus is the most abundant photoautotroph and contributes substantially to global CO2 fixation. In the vast euphotic zones of the open ocean, Prochlorococcus converts CO2 into organic compounds and supports diverse organisms, forming an intricate network of interactions that regulate the magnitude of carbon cycling and storage in the ocean. An understanding of the biological interactions with Prochlorococcus is critical for accurately estimating the contributions of Prochlorococcus and interacting organisms to the marine carbon cycle. This review synthesizes the primary production contributed by Prochlorococcus in the global ocean. We outline recent progress on the interactions of Prochlorococcus with heterotrophic bacteria, phages, and grazers that multifacetedly determine Prochlorococcus carbon production and fate. We discuss that climate change might affect the biological interactions with Prochlorococcus and thus the marine carbon cycle.
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Affiliation(s)
- Lanlan Cai
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, China
| | - Haofu Li
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China
| | - Junwei Deng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ruiqian Zhou
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China; HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute, Shenzhen, China; Center for Ocean Research in Hong Kong and Macau, The Hong Kong University of Science and Technology, Hong Kong, China.
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2
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Zimmerman AE, Podowski JC, Gallagher GE, Coleman ML, Waldbauer JR. Tracking nitrogen allocation to proteome biosynthesis in a marine microbial community. Nat Microbiol 2023; 8:498-509. [PMID: 36635571 DOI: 10.1038/s41564-022-01303-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 12/12/2022] [Indexed: 01/14/2023]
Abstract
Microbial growth in many environments is limited by nitrogen availability, yet there is limited understanding of how complex communities compete for and allocate this resource. Here we develop a broadly applicable approach to track biosynthetic incorporation of 15N-labelled nitrogen substrates into microbial community proteomes, enabling quantification of protein turnover and N allocation to specific cellular functions in individual taxa. Application to oligotrophic ocean surface water identifies taxa-specific substrate preferences and a distinct subset of protein functions undergoing active biosynthesis. The cyanobacterium Prochlorococcus is the most effective competitor for acquisition of ammonium and urea and shifts its proteomic allocation of N over the day/night cycle. Our approach reveals that infrastructure and protein-turnover functions comprise substantial biosynthetic demand for N in Prochlorococcus and a range of other microbial taxa. The direct interrogation of the proteomic underpinnings of N limitation with 15N-tracking proteomics illuminates how nutrient stress differentially influences metabolism in co-existing microbes.
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Affiliation(s)
- Amy E Zimmerman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.,Biological Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA, USA
| | - Justin C Podowski
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.,Division of Data Science and Learning, Argonne National Laboratory, Argonne, IL, USA
| | - Gwendolyn E Gallagher
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.,New York Sea Grant, Stony Brook University, Stony Brook, NY, USA
| | - Maureen L Coleman
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Jacob R Waldbauer
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA.
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3
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Baroukh C, Mairet F, Bernard O. The paradoxes hidden behind the Droop model highlighted by a metabolic approach. FRONTIERS IN PLANT SCIENCE 2022; 13:941230. [PMID: 36072315 PMCID: PMC9442053 DOI: 10.3389/fpls.2022.941230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
We propose metabolic models for the haptophyte microalgae Tisochrysis lutea with different possible organic carbon excretion mechanisms. These models-based on the DRUM (Dynamic Reduction of Unbalanced Metabolism) methodology-are calibrated with an experiment of nitrogen starvation under day/night cycles, and then validated with nitrogen-limited chemostat culture under continuous light. We show that models including exopolysaccharide excretion offer a better prediction capability. It also gives an alternative mechanistic interpretation to the Droop model for nitrogen limitation, which can be understood as an accumulation of carbon storage during nitrogen stress, rather than the common belief of a nitrogen pool driving growth. Excretion of organic carbon limits its accumulation, which leads to a maximal C/N ratio (corresponding to the minimum Droop N/C quota). Although others phenomena-including metabolic regulations and dissipation of energy-are possibly at stake, excretion appears as a key component in our metabolic model, that we propose to include in the Droop model.
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Affiliation(s)
- Caroline Baroukh
- LIPME, Université de Toulouse, INRAE, CNRS, Castanet-Tolosan, France
| | | | - Olivier Bernard
- Biocore, INRIA, Université Côte d'Azur, Sophia Antipolis, France
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4
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Moran MA, Kujawinski EB, Schroer WF, Amin SA, Bates NR, Bertrand EM, Braakman R, Brown CT, Covert MW, Doney SC, Dyhrman ST, Edison AS, Eren AM, Levine NM, Li L, Ross AC, Saito MA, Santoro AE, Segrè D, Shade A, Sullivan MB, Vardi A. Microbial metabolites in the marine carbon cycle. Nat Microbiol 2022; 7:508-523. [PMID: 35365785 DOI: 10.1038/s41564-022-01090-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 02/23/2022] [Indexed: 01/08/2023]
Abstract
One-quarter of photosynthesis-derived carbon on Earth rapidly cycles through a set of short-lived seawater metabolites that are generated from the activities of marine phytoplankton, bacteria, grazers and viruses. Here we discuss the sources of microbial metabolites in the surface ocean, their roles in ecology and biogeochemistry, and approaches that can be used to analyse them from chemistry, biology, modelling and data science. Although microbial-derived metabolites account for only a minor fraction of the total reservoir of marine dissolved organic carbon, their flux and fate underpins the central role of the ocean in sustaining life on Earth.
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Affiliation(s)
- Mary Ann Moran
- Department of Marine Sciences, University of Georgia, Athens, GA, USA.
| | - Elizabeth B Kujawinski
- Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA, USA.
| | - William F Schroer
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Shady A Amin
- Division of Science, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Nicholas R Bates
- Bermuda Institute of Ocean Sciences, St George's, Bermuda.,School of Ocean and Earth Sciences, University of Southampton, Southampton, UK
| | - Erin M Bertrand
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Rogier Braakman
- Departments of Earth, Atmospheric and Planetary Sciences, and Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - C Titus Brown
- Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA
| | - Markus W Covert
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Scott C Doney
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | - Sonya T Dyhrman
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA.,Department of Earth and Environmental Science, Columbia University, Palisades, NY, USA
| | - Arthur S Edison
- Departments of Biochemistry and Genetics, Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
| | - A Murat Eren
- Josephine Bay Paul Center, Marine Biological Laboratory, Woods Hole, MA, USA.,Helmholtz-Institute for Functional Marine Biodiversity (HIFMB), University of Oldenburg, Oldenburg, Germany
| | - Naomi M Levine
- Marine and Environmental Biology, Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Liang Li
- Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Avena C Ross
- Department of Chemistry, Queen's University, Kingston, Ontario, Canada
| | - Mak A Saito
- Department of Marine Sciences, University of Georgia, Athens, GA, USA
| | - Alyson E Santoro
- Department of Ecology, Evolution and Marine Biology, University of California, Santa Barbara, CA, USA
| | - Daniel Segrè
- Department of Biology and Bioinformatics Program, Boston University, Boston, MA, USA
| | - Ashley Shade
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, USA
| | - Matthew B Sullivan
- Departments of Microbiology and Civil, Environmental, and Geodetic Engineering, and Center of Microbiome Science, The Ohio State University, Columbus, OH, USA
| | - Assaf Vardi
- Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel
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5
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Eigemann F, Rahav E, Grossart HP, Aharonovich D, Sher D, Vogts A, Voss M. Phytoplankton exudates provide full nutrition to a subset of accompanying heterotrophic bacteria via carbon, nitrogen and phosphorus allocation. Environ Microbiol 2022; 24:2467-2483. [PMID: 35146867 DOI: 10.1111/1462-2920.15933] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 02/03/2022] [Indexed: 11/28/2022]
Abstract
Marine bacteria rely on phytoplankton exudates as carbon sources (DOCp). Yet, it is unclear to what extent phytoplankton exudates also provide nutrients such as phytoplankton-derived N and P (DONp, DOPp). We address these questions by mesocosm exudate addition experiments with spent media from the ubiquitous pico-cyanobacterium Prochlorococcus to bacterial communities in contrasting ecosystems in the Eastern Mediterranean - a coastal and an open-ocean, oligotrophic station with and without on-top additions of inorganic nutrients. Inorganic nutrient addition did not lower the incorporation of exudate DONp, nor did it reduce alkaline phosphatase activity, suggesting that bacterial communities are able to exclusively cover their nitrogen and phosphorus demands with organic forms provided by phytoplankton exudates. Approximately half of the cells in each ecosystem took up detectable amounts of Prochlorococcus-derived C and N, yet based on 16S rRNA sequencing different bacterial genera were responsible for the observed exudate utilization patterns. In the coastal community, several phylotypes of Aureimarina, Psychrosphaera and Glaciecola responded positively to the addition of phytoplankton exudates, whereas phylotypes of Pseudoalteromonas increased and dominated the open-ocean communities. Together, our results strongly indicate that phytoplankton exudates provide coastal and open-ocean bacterial communities with organic carbon, nitrogen and phosphorus, and that phytoplankton exudate serve a full-fledged meal for the accompanying bacterial community in the nutrient-poor eastern Mediterranean. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Falk Eigemann
- Leibniz-Institute for Baltic Sea Research Warnemünde.,Water quality engineering, Technical University of Berlin
| | - Eyal Rahav
- Israel Oceanographic and Limnological Research, Haifa
| | | | | | - Daniel Sher
- Leon H. Charney School of Marine Sciences, University Haifa
| | - Angela Vogts
- Leibniz-Institute for Baltic Sea Research Warnemünde
| | - Maren Voss
- Leibniz-Institute for Baltic Sea Research Warnemünde
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6
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Casey JR, Boiteau RM, Engqvist MKM, Finkel ZV, Li G, Liefer J, Müller CL, Muñoz N, Follows MJ. Basin-scale biogeography of marine phytoplankton reflects cellular-scale optimization of metabolism and physiology. SCIENCE ADVANCES 2022; 8:eabl4930. [PMID: 35061539 PMCID: PMC8782455 DOI: 10.1126/sciadv.abl4930] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Extensive microdiversity within Prochlorococcus, the most abundant marine cyanobacterium, occurs at scales from a single droplet of seawater to ocean basins. To interpret the structuring role of variations in genetic potential, as well as metabolic and physiological acclimation, we developed a mechanistic constraint-based modeling framework that incorporates the full suite of genes, proteins, metabolic reactions, pigments, and biochemical compositions of 69 sequenced isolates spanning the Prochlorococcus pangenome. Optimizing each strain to the local, observed physical and chemical environment along an Atlantic Ocean transect, we predicted variations in strain-specific patterns of growth rate, metabolic configuration, and physiological state, defining subtle niche subspaces directly attributable to differences in their encoded metabolic potential. Predicted growth rates covaried with observed ecotype abundances, affirming their significance as a measure of fitness and inferring a nonlinear density dependence of mortality. Our study demonstrates the potential to interpret global-scale ecosystem organization in terms of cellular-scale processes.
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Affiliation(s)
- John R. Casey
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- School of Ocean and Earth Science and Technology, University of Hawai‘i at Ma¯noa, Honolulu, HI, USA
| | - Rene M. Boiteau
- College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
| | - Martin K. M. Engqvist
- Department of Biology and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Zoe V. Finkel
- Department of Oceanography, Dalhousie University, Halifax, NS, Canada
| | - Gang Li
- Department of Biology and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden
| | - Justin Liefer
- Department of Biology, Mount Allison University, Sackville, NB, Canada
| | | | - Nathalie Muñoz
- Environmental Molecular Sciences Division, Pacific Northwest National Laboratories, Richland, WA, USA
| | - Michael J. Follows
- Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
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7
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Abstract
Biological nitrogen fixation in rhizobium-legume symbioses is of major importance for sustainable agricultural practices. To establish a mutualistic relationship with their plant host, rhizobia transition from free-living bacteria in soil to growth down infection threads inside plant roots and finally differentiate into nitrogen-fixing bacteroids. We reconstructed a genome-scale metabolic model for Rhizobium leguminosarum and integrated the model with transcriptome, proteome, metabolome, and gene essentiality data to investigate nutrient uptake and metabolic fluxes characteristic of these different lifestyles. Synthesis of leucine, polyphosphate, and AICAR is predicted to be important in the rhizosphere, while myo-inositol catabolism is active in undifferentiated nodule bacteria in agreement with experimental evidence. The model indicates that bacteroids utilize xylose and glycolate in addition to dicarboxylates, which could explain previously described gene expression patterns. Histidine is predicted to be actively synthesized in bacteroids, consistent with transcriptome and proteome data for several rhizobial species. These results provide the basis for targeted experimental investigation of metabolic processes specific to the different stages of the rhizobium-legume symbioses. IMPORTANCE Rhizobia are soil bacteria that induce nodule formation on plant roots and differentiate into nitrogen-fixing bacteroids. A detailed understanding of this complex symbiosis is essential for advancing ongoing efforts to engineer novel symbioses with cereal crops for sustainable agriculture. Here, we reconstruct and validate a genome-scale metabolic model for Rhizobium leguminosarum bv. viciae 3841. By integrating the model with various experimental data sets specific to different stages of symbiosis formation, we elucidate the metabolic characteristics of rhizosphere bacteria, undifferentiated bacteria inside root nodules, and nitrogen-fixing bacteroids. Our model predicts metabolic flux patterns for these three distinct lifestyles, thus providing a framework for the interpretation of genome-scale experimental data sets and identifying targets for future experimental studies.
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8
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Dukovski I, Bajić D, Chacón JM, Quintin M, Vila JCC, Sulheim S, Pacheco AR, Bernstein DB, Riehl WJ, Korolev KS, Sanchez A, Harcombe WR, Segrè D. A metabolic modeling platform for the computation of microbial ecosystems in time and space (COMETS). Nat Protoc 2021; 16:5030-5082. [PMID: 34635859 PMCID: PMC10824140 DOI: 10.1038/s41596-021-00593-3] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 06/16/2021] [Indexed: 02/08/2023]
Abstract
Genome-scale stoichiometric modeling of metabolism has become a standard systems biology tool for modeling cellular physiology and growth. Extensions of this approach are emerging as a valuable avenue for predicting, understanding and designing microbial communities. Computation of microbial ecosystems in time and space (COMETS) extends dynamic flux balance analysis to generate simulations of multiple microbial species in molecularly complex and spatially structured environments. Here we describe how to best use and apply the most recent version of COMETS, which incorporates a more accurate biophysical model of microbial biomass expansion upon growth, evolutionary dynamics and extracellular enzyme activity modules. In addition to a command-line option, COMETS includes user-friendly Python and MATLAB interfaces compatible with the well-established COBRA models and methods, as well as comprehensive documentation and tutorials. This protocol provides a detailed guideline for installing, testing and applying COMETS to different scenarios, generating simulations that take from a few minutes to several days to run, with broad applicability to microbial communities across biomes and scales.
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Affiliation(s)
- Ilija Dukovski
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
| | - Djordje Bajić
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
| | - Jeremy M Chacón
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, USA
- BioTechnology Institute, University of Minnesota, St. Paul, MN, USA
| | - Michael Quintin
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
| | - Jean C C Vila
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
| | - Snorre Sulheim
- Bioinformatics Program, Boston University, Boston, MA, USA
- Department of Biotechnology and Food Science, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Alan R Pacheco
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
| | - David B Bernstein
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - William J Riehl
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Kirill S Korolev
- Bioinformatics Program, Boston University, Boston, MA, USA
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Physics, Boston University, Boston, MA, USA
| | - Alvaro Sanchez
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT, USA
- Microbial Sciences Institute, Yale University, West Haven, CT, USA
| | - William R Harcombe
- Department of Ecology, Evolution and Behavior, University of Minnesota, St. Paul, MN, USA
- BioTechnology Institute, University of Minnesota, St. Paul, MN, USA
| | - Daniel Segrè
- Bioinformatics Program, Boston University, Boston, MA, USA.
- Biological Design Center, Boston University, Boston, MA, USA.
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
- Department of Physics, Boston University, Boston, MA, USA.
- Department of Biology, Boston University, Boston, MA, USA.
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9
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Bernstein DB, Sulheim S, Almaas E, Segrè D. Addressing uncertainty in genome-scale metabolic model reconstruction and analysis. Genome Biol 2021; 22:64. [PMID: 33602294 PMCID: PMC7890832 DOI: 10.1186/s13059-021-02289-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 02/04/2021] [Indexed: 02/07/2023] Open
Abstract
The reconstruction and analysis of genome-scale metabolic models constitutes a powerful systems biology approach, with applications ranging from basic understanding of genotype-phenotype mapping to solving biomedical and environmental problems. However, the biological insight obtained from these models is limited by multiple heterogeneous sources of uncertainty, which are often difficult to quantify. Here we review the major sources of uncertainty and survey existing approaches developed for representing and addressing them. A unified formal characterization of these uncertainties through probabilistic approaches and ensemble modeling will facilitate convergence towards consistent reconstruction pipelines, improved data integration algorithms, and more accurate assessment of predictive capacity.
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Affiliation(s)
- David B Bernstein
- Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA, USA
| | - Snorre Sulheim
- Bioinformatics Program, Boston University, Boston, MA, USA
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- Department of Biotechnology and Nanomedicine, SINTEF Industry, Trondheim, Norway
| | - Eivind Almaas
- Department of Biotechnology and Food Science, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
- K.G. Jebsen Center for Genetic Epidemiology, NTNU - Norwegian University of Science and Technology, Trondheim, Norway
| | - Daniel Segrè
- Department of Biomedical Engineering and Biological Design Center, Boston University, Boston, MA, USA.
- Bioinformatics Program, Boston University, Boston, MA, USA.
- Department of Biology and Department of Physics, Boston University, Boston, MA, USA.
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