1
|
Chakrawal A, Lindahl BD, Manzoni S. Modelling optimal ligninolytic activity during plant litter decomposition. THE NEW PHYTOLOGIST 2024; 243:866-880. [PMID: 38343140 DOI: 10.1111/nph.19572] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/22/2024] [Indexed: 07/05/2024]
Abstract
A large fraction of plant litter comprises recalcitrant aromatic compounds (lignin and other phenolics). Quantifying the fate of aromatic compounds is difficult, because oxidative degradation of aromatic carbon (C) is a costly but necessary endeavor for microorganisms, and we do not know when gains from the decomposition of aromatic C outweigh energetic costs. To evaluate these tradeoffs, we developed a litter decomposition model in which the aromatic C decomposition rate is optimized dynamically to maximize microbial growth for the given costs of maintaining ligninolytic activity. We tested model performance against > 200 litter decomposition datasets collected from published literature and assessed the effects of climate and litter chemistry on litter decomposition. The model predicted a time-varying ligninolytic oxidation rate, which was used to calculate the lag time before the decomposition of aromatic C is initiated. Warmer conditions increased decomposition rates, shortened the lag time of aromatic C oxidation, and improved microbial C-use efficiency by decreasing the costs of oxidation. Moreover, a higher initial content of aromatic C promoted an earlier start of aromatic C decomposition under any climate. With this contribution, we highlight the application of eco-evolutionary approaches based on optimized microbial life strategies as an alternative parametrization scheme for litter decomposition models.
Collapse
Affiliation(s)
- Arjun Chakrawal
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
| | - Björn D Lindahl
- Swedish University of Agricultural Sciences, Department of Soil and Environment, 75007, Uppsala, Sweden
| | - Stefano Manzoni
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, 10691, Stockholm, Sweden
| |
Collapse
|
2
|
Abdoli P, Vulin C, Lepiz M, Chase AB, Weihe C, Rodríguez-Verdugo A. Substrate complexity buffers negative interactions in a synthetic community of leaf litter degraders. FEMS Microbiol Ecol 2024; 100:fiae102. [PMID: 39020097 PMCID: PMC11289631 DOI: 10.1093/femsec/fiae102] [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: 01/13/2024] [Revised: 07/02/2024] [Accepted: 07/16/2024] [Indexed: 07/19/2024] Open
Abstract
Leaf litter microbes collectively degrade plant polysaccharides, influencing land-atmosphere carbon exchange. An open question is how substrate complexity-defined as the structure of the saccharide and the amount of external processing by extracellular enzymes-influences species interactions. We tested the hypothesis that monosaccharides (i.e. xylose) promote negative interactions through resource competition, and polysaccharides (i.e. xylan) promote neutral or positive interactions through resource partitioning or synergism among extracellular enzymes. We assembled a three-species community of leaf litter-degrading bacteria isolated from a grassland site in Southern California. In the polysaccharide xylan, pairs of species stably coexisted and grew equally in coculture and in monoculture. Conversely, in the monosaccharide xylose, competitive exclusion and negative interactions prevailed. These pairwise dynamics remained consistent in a three-species community: all three species coexisted in xylan, while only two species coexisted in xylose, with one species capable of using peptone. A mathematical model showed that in xylose these dynamics could be explained by resource competition. Instead, the model could not predict the coexistence patterns in xylan, suggesting other interactions exist during biopolymer degradation. Overall, our study shows that substrate complexity influences species interactions and patterns of coexistence in a synthetic microbial community of leaf litter degraders.
Collapse
Affiliation(s)
- Parmis Abdoli
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697, United States
| | - Clément Vulin
- Department of Fundamental Microbiology, University of Lausanne, Biophore, CH-1015 Lausanne, Switzerland
| | - Miriam Lepiz
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697, United States
| | - Alexander B Chase
- Department of Earth Sciences, Southern Methodist University, 3225 Daniel Avenue, Suite 207, Heroy Hall, Dallas, TX 75205, United States
| | - Claudia Weihe
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697, United States
| | - Alejandra Rodríguez-Verdugo
- Department of Ecology and Evolutionary Biology, University of California Irvine, 321 Steinhaus Hall, Irvine, CA 92697, United States
| |
Collapse
|
3
|
Abs E, Chase AB, Manzoni S, Ciais P, Allison SD. Microbial evolution-An under-appreciated driver of soil carbon cycling. GLOBAL CHANGE BIOLOGY 2024; 30:e17268. [PMID: 38562029 DOI: 10.1111/gcb.17268] [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: 12/20/2023] [Revised: 03/18/2024] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Although substantial advances in predicting the ecological impacts of global change have been made, predictions of the evolutionary impacts have lagged behind. In soil ecosystems, microbes act as the primary energetic drivers of carbon cycling; however, microbes are also capable of evolving on timescales comparable to rates of global change. Given the importance of soil ecosystems in global carbon cycling, we assess the potential impact of microbial evolution on carbon-climate feedbacks in this system. We begin by reviewing the current state of knowledge concerning microbial evolution in response to global change and its specific effect on soil carbon dynamics. Through this integration, we synthesize a roadmap detailing how to integrate microbial evolution into ecosystem biogeochemical models. Specifically, we highlight the importance of microscale mechanistic soil carbon models, including choosing an appropriate evolutionary model (e.g., adaptive dynamics, quantitative genetics), validating model predictions with 'omics' and experimental data, scaling microbial adaptations to ecosystem level processes, and validating with ecosystem-scale measurements. The proposed steps will require significant investment of scientific resources and might require 10-20 years to be fully implemented. However, through the application of multi-scale integrated approaches, we will advance the integration of microbial evolution into predictive understanding of ecosystems, providing clarity on its role and impact within the broader context of environmental change.
Collapse
Affiliation(s)
- Elsa Abs
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, California, USA
- Laboratoire Des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Alexander B Chase
- Department of Earth Sciences, Southern Methodist University, Dallas, Texas, USA
| | - Stefano Manzoni
- Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden
| | - Philippe Ciais
- Laboratoire Des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Steven D Allison
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, California, USA
- Department of Earth System Science, University of California, Irvine, Irvine, California, USA
| |
Collapse
|
4
|
Omondi VO, Bosire GO, Onyari JM, Kibet C, Mwasya S, Onyonyi VN, Getahun MN. Multi-omics analyses reveal rumen microbes and secondary metabolites that are unique to livestock species. mSystems 2024; 9:e0122823. [PMID: 38294243 PMCID: PMC10878066 DOI: 10.1128/msystems.01228-23] [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: 11/21/2023] [Accepted: 12/21/2023] [Indexed: 02/01/2024] Open
Abstract
Ruminant livestock, including cattle, sheep, goats, and camels, possess a distinctive digestive system with complex microbiota communities critical for feed conversion and secondary metabolite production, including greenhouse gases. Yet, there is limited knowledge regarding the diversity of rumen microbes and metabolites benefiting livestock physiology, productivity, climate impact, and defense mechanisms across ruminant species. In this study, we utilized metataxonomics and metabolomics data from four evolutionarily distinct livestock species, which had fed on diverse plant materials like grass, shrubs, and acacia trees, to uncover the unique signature microbes and secondary metabolites. We established the presence of a distinctive anaerobic fungus called Oontomyces in camels, while cattle exhibited a higher prevalence of unique microbes like Psychrobacter, Anaeromyces, Cyllamyces, and Orpinomyces. Goats hosted Cleistothelebolus, and Liebetanzomyces was unique to sheep. Furthermore, we identified a set of conserved core microbes, including Prevotella, Rickenellaceae, Cladosporium, and Pecoramyces, present in all the ruminants, irrespective of host genetics and dietary composition. This underscores their indispensable role in maintaining crucial physiological functions. Regarding secondary metabolites, camel's rumen is rich in organic acids, goat's rumen is rich in alcohols and hydrocarbons, sheep's rumen is rich in indoles, and cattle's rumen is rich in sesquiterpenes. Additionally, linalool propionate and terpinolene were uniquely found in sheep rumen, while valencene was exclusive to cattle. This may suggest the existence of species-specific microbes and metabolites that require host rumen-microbes' environment balance. These results have implications for manipulating the rumen environment to target specific microbes and secondary metabolite networks, thereby enhancing livestock productivity, resilience, reducing susceptibility to vectors, and environmentally preferred livestock husbandry.IMPORTANCERumen fermentation, which depends on feed components and rumen microbes, plays a crucial role in feed conversion and the production of various metabolites important for the physiological functions, health, and environmental smartness of ruminant livestock, in addition to providing food for humans. However, given the complexity and variation of the rumen ecosystem and feed of these various livestock species, combined with inter-individual differences between gut microbial communities, how they influence the rumen secondary metabolites remains elusive. Using metagenomics and metabolomics approaches, we show that each livestock species has a signature microbe(s) and secondary metabolites. These findings may contribute toward understanding the rumen ecosystem, microbiome and metabolite networks, which may provide a gateway to manipulating rumen ecosystem pathways toward making livestock production efficient, sustainable, and environmentally friendly.
Collapse
Affiliation(s)
- Victor O. Omondi
- Animal Health Theme and Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
- Department of Chemistry, University of Nairobi (U.o.N), Nairobi, Kenya
| | | | - John M. Onyari
- Department of Chemistry, University of Nairobi (U.o.N), Nairobi, Kenya
| | - Caleb Kibet
- Animal Health Theme and Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Samuel Mwasya
- Animal Health Theme and Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Vanessa N. Onyonyi
- Animal Health Theme and Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| | - Merid N. Getahun
- Animal Health Theme and Behavioural and Chemical Ecology Unit, International Centre of Insect Physiology and Ecology (icipe), Nairobi, Kenya
| |
Collapse
|
5
|
Bååth E, Kritzberg ES. Temperature Adaptation of Aquatic Bacterial Community Growth Is Faster in Response to Rising than to Falling Temperature. MICROBIAL ECOLOGY 2024; 87:38. [PMID: 38296863 PMCID: PMC10830665 DOI: 10.1007/s00248-024-02353-8] [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: 12/14/2023] [Accepted: 01/25/2024] [Indexed: 02/02/2024]
Abstract
Bacteria are key organisms in energy and nutrient cycles, and predicting the effects of temperature change on bacterial activity is important in assessing global change effects. A changing in situ temperature will affect the temperature adaptation of bacterial growth in lake water, both long term in response to global change, and short term in response to seasonal variations. The rate of adaptation may, however, depend on whether temperature is increasing or decreasing, since bacterial growth and turnover scale with temperature. Temperature adaptation was studied for winter (in situ temperature 2.5 °C) and summer communities (16.5 °C) from a temperate lake in Southern Sweden by exposing them to a temperature treatment gradient between 0 and 30 °C in ~ 5 °C increments. This resulted mainly in a temperature increase for the winter and a decrease for the summer community. Temperature adaptation of bacterial community growth was estimated as leucine incorporation using a temperature Sensitivity Index (SI, log growth at 35 °C/4 °C), where higher values indicate adaptation to higher temperatures. High treatment temperatures resulted in higher SI within days for the winter community, resulting in an expected level of community adaptation within 2 weeks. Adaptation for the summer community was also correlated to treatment temperature, but the rate of adaption was slower. Even after 5 weeks, the bacterial community had not fully adapted to the lowest temperature conditions. Thus, during periods of increasing temperature, the bacterial community will rapidly adapt to function optimally, while decreasing temperature may result in long periods of non-optimal functioning.
Collapse
Affiliation(s)
- Erland Bååth
- Microbial Ecology, Department of Biology, Lund University, S-223 62, Lund, Sweden.
| | - Emma S Kritzberg
- Aquatic Ecology, Department of Biology, Lund University, S-223 62, Lund, Sweden
| |
Collapse
|
6
|
Barbour KM, Martiny JBH. Investigating eco-evolutionary processes of microbial community assembly in the wild using a model leaf litter system. THE ISME JOURNAL 2024; 18:wrae043. [PMID: 38506671 PMCID: PMC11008689 DOI: 10.1093/ismejo/wrae043] [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: 12/22/2023] [Revised: 02/13/2024] [Accepted: 03/19/2024] [Indexed: 03/21/2024]
Abstract
Microbial communities are not the easiest to manipulate experimentally in natural ecosystems. However, leaf litter-topmost layer of surface soil-is uniquely suitable to investigate the complexities of community assembly. Here, we reflect on over a decade of collaborative work to address this topic using leaf litter as a model system in Southern California ecosystems. By leveraging a number of methodological advantages of the system, we have worked to demonstrate how four processes-selection, dispersal, drift, and diversification-contribute to bacterial and fungal community assembly and ultimately impact community functioning. Although many dimensions remain to be investigated, our initial results demonstrate that both ecological and evolutionary processes occur simultaneously to influence microbial community assembly. We propose that the development of additional and experimentally tractable microbial systems will be enormously valuable to test the role of eco-evolutionary processes in natural settings and their implications in the face of rapid global change.
Collapse
Affiliation(s)
- Kristin M Barbour
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, United States
| | - Jennifer B H Martiny
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, United States
| |
Collapse
|
7
|
Quiroga MV, Stegen JC, Mataloni G, Cowan D, Lebre PH, Valverde A. Microdiverse bacterial clades prevail across Antarctic wetlands. Mol Ecol 2024; 33:e17189. [PMID: 37909659 DOI: 10.1111/mec.17189] [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: 07/17/2023] [Revised: 10/06/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023]
Abstract
Antarctica's extreme environmental conditions impose selection pressures on microbial communities. Indeed, a previous study revealed that bacterial assemblages at the Cierva Point Wetland Complex (CPWC) are shaped by strong homogeneous selection. Yet which bacterial phylogenetic clades are shaped by selection processes and their ecological strategies to thrive in such extreme conditions remain unknown. Here, we applied the phyloscore and feature-level βNTI indexes coupled with phylofactorization to successfully detect bacterial monophyletic clades subjected to homogeneous (HoS) and heterogenous (HeS) selection. Remarkably, only the HoS clades showed high relative abundance across all samples and signs of putative microdiversity. The majority of the amplicon sequence variants (ASVs) within each HoS clade clustered into a unique 97% sequence similarity operational taxonomic unit (OTU) and inhabited a specific environment (lotic, lentic or terrestrial). Our findings suggest the existence of microdiversification leading to sub-taxa niche differentiation, with putative distinct ecotypes (consisting of groups of ASVs) adapted to a specific environment. We hypothesize that HoS clades thriving in the CPWC have phylogenetically conserved traits that accelerate their rate of evolution, enabling them to adapt to strong spatio-temporally variable selection pressures. Variable selection appears to operate within clades to cause very rapid microdiversification without losing key traits that lead to high abundance. Variable and homogeneous selection, therefore, operate simultaneously but on different aspects of organismal ecology. The result is an overall signal of homogeneous selection due to rapid within-clade microdiversification caused by variable selection. It is unknown whether other systems experience this dynamic, and we encourage future work evaluating the transferability of our results.
Collapse
Affiliation(s)
- María V Quiroga
- Instituto Tecnológico de Chascomús (CONICET-UNSAM), Buenos Aires, Argentina
- Escuela de Bio y Nanotecnologías (UNSAM), Buenos Aires, Argentina
| | - James C Stegen
- Pacific Northwest National Laboratory, Ecosystem Science Team, Richland, Washington, USA
| | - Gabriela Mataloni
- Instituto de Investigación e Ingeniería Ambiental (IIIA, CONICET-UNSAM), Buenos Aires, Argentina
| | - Don Cowan
- Centre for Microbial Ecology and Genomics (CMEG), Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Pedro H Lebre
- Centre for Microbial Ecology and Genomics (CMEG), Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Angel Valverde
- Instituto de Recursos Naturales y Agrobiología de Salamanca (IRNASA), Consejo Superior de Investigaciones Científicas (CSIC), Salamanca, Spain
| |
Collapse
|
8
|
Ranheim Sveen T, Hannula SE, Bahram M. Microbial regulation of feedbacks to ecosystem change. Trends Microbiol 2024; 32:68-78. [PMID: 37500365 DOI: 10.1016/j.tim.2023.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 07/29/2023]
Abstract
Microbes are key biodiversity components of all ecosystems and control vital ecosystem functions. Although we have just begun to unravel the scales and factors that regulate microbial communities, their role in mediating ecosystem stability in response to disturbances remains underexplored. Here, we review evidence of how, when, and where microbes regulate or drive disturbance feedbacks. Negative feedbacks dampen the impacts of disturbance, which maintain ecosystem stability, whereas positive feedbacks instead erode stability by amplifying the disturbance. Here we describe the processes underlying the responses to disturbance using a hierarchy of functional traits, and we exemplify how these may drive biogeochemical feedbacks. We suggest that the feedback potential of functional traits at different hierarchical levels is contingent on the complexity and heterogeneity of the environment.
Collapse
Affiliation(s)
- T Ranheim Sveen
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls Väg 16, 756 51 Uppsala, Sweden.
| | - S E Hannula
- Institute of Environmental Sciences, Leiden University, Leiden 2333, The Netherlands
| | - M Bahram
- Department of Ecology, Swedish University of Agricultural Sciences, Ulls Väg 16, 756 51 Uppsala, Sweden; Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia
| |
Collapse
|
9
|
Jarne P, Pinay G. Towards closer integration between ecology and evolution. Ecol Lett 2023; 26 Suppl 1:S5-S10. [PMID: 37840023 DOI: 10.1111/ele.14298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 07/24/2023] [Accepted: 07/25/2023] [Indexed: 10/17/2023]
Affiliation(s)
- Philippe Jarne
- CEFE, UMR 5175, CNRS-Université de Montpellier-IRD-EPHE, Montpellier Cedex 5, France
| | - Gilles Pinay
- Environnement, Ville & Société (EVS), UMR 5600, CNRS-, Lyon Cedex 08, France
| |
Collapse
|