1
|
Chaudhari NM, Pérez-Carrascal OM, Overholt WA, Totsche KU, Küsel K. Genome streamlining in Parcubacteria transitioning from soil to groundwater. ENVIRONMENTAL MICROBIOME 2024; 19:41. [PMID: 38902796 PMCID: PMC11188291 DOI: 10.1186/s40793-024-00581-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 06/03/2024] [Indexed: 06/22/2024]
Abstract
BACKGROUND To better understand the influence of habitat on the genetic content of bacteria, with a focus on members of Candidate Phyla Radiation (CPR) bacteria, we studied the effects of transitioning from soil via seepage waters to groundwater on genomic composition of ultra-small Parcubacteria, the dominating CPR class in seepage waters, using genome resolved metagenomics. RESULTS Bacterial metagenome-assembled genomes (MAGs), (318 total, 32 of Parcubacteria) were generated from seepage waters and compared directly to groundwater counterparts. The estimated average genome sizes of members of major phyla Proteobacteria, Bacteroidota and Cand. Patescibacteria (Candidate Phyla Radiation - CPR bacteria) were significantly higher in soil-seepage water as compared to their groundwater counterparts. Seepage water Parcubacteria (Paceibacteria) exhibited 1.18-fold greater mean genome size and 2-fold lower mean proportion of pseudogenes than those in groundwater. Bacteroidota and Proteobacteria also showed a similar trend of reduced genomes in groundwater compared to seepage. While exploring gene loss and adaptive gains in closely related CPR lineages in groundwater, we identified a membrane protein, and a lipoglycopeptide resistance gene unique to a seepage Parcubacterium genome. A nitrite reductase gene was also identified and was unique to the groundwater Parcubacteria genomes, likely acquired from other planktonic microbes via horizontal gene transfer. CONCLUSIONS Overall, our data suggest that bacteria in seepage waters, including ultra-small Parcubacteria, have significantly larger genomes and higher metabolic enrichment than their groundwater counterparts, highlighting possible genome streamlining of the latter in response to habitat selection in an oligotrophic environment.
Collapse
Affiliation(s)
- Narendrakumar M Chaudhari
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Friedrich-Schiller-Universität, Leipzig, Germany
| | - Olga M Pérez-Carrascal
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | - Will A Overholt
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany
| | - Kai U Totsche
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
- Hydrogeology, Institute of Geowissenschaften, Friedrich-Schiller-Universität Jena, Burgweg 11, 07749, Jena, Germany
| | - Kirsten Küsel
- Aquatic Geomicrobiology, Institute of Biodiversity, Friedrich Schiller University Jena, Jena, Germany.
- German Center for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Friedrich-Schiller-Universität, Leipzig, Germany.
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany.
| |
Collapse
|
2
|
Shah M, Bornemann TLV, Nuy JK, Hahn MW, Probst AJ, Beisser D, Boenigk J. Genome-resolved metagenomics reveals the effect of nutrient availability on bacterial genomic properties across 44 European freshwater lakes. Environ Microbiol 2024; 26:e16634. [PMID: 38881319 DOI: 10.1111/1462-2920.16634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 04/25/2024] [Indexed: 06/18/2024]
Abstract
Understanding intricate microbial interactions in the environment is crucial. This is especially true for the relationships between nutrients and bacteria, as phosphorus, nitrogen and organic carbon availability are known to influence bacterial population dynamics. It has been suggested that low nutrient conditions prompt the evolutionary process of genome streamlining. This process helps conserve scarce nutrients and allows for proliferation. Genome streamlining is associated with genomic properties such as %GC content, genes encoding sigma factors, percent coding regions, gene redundancy, and functional shifts in processes like cell motility and ATP binding cassette transporters, among others. The current study aims to unveil the impact of nutrition on the genome size, %GC content, and functional properties of pelagic freshwater bacteria. We do this at finer taxonomic resolutions for many metagenomically characterized communities. Our study confirms the interplay of trophic level and genomic properties. It also highlights that different nutrient types, particularly phosphorus and nitrogen, impact these properties differently. We observed a covariation of functional traits with genome size. Larger genomes exhibit enriched pathways for motility, environmental interaction, and regulatory genes. ABC transporter genes reflect the availability of nutrients in the environment, with small genomes presumably relying more on metabolites from other organisms. We also discuss the distinct strategies different phyla adopt to adapt to oligotrophic environments. The findings contribute to our understanding of genomic adaptations within complex microbial communities.
Collapse
Affiliation(s)
- Manan Shah
- Department of Biodiversity, University of Duisburg-Essen, Essen, Germany
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, University of Duisburg-Essen, Essen, Germany
- Department of Engineering and Natural Sciences, Westphalian University of Applied Science, Recklinghausen, Germany
| | - Till L V Bornemann
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research, University of Duisburg-Essen, Essen, Germany
| | - Julia K Nuy
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research, University of Duisburg-Essen, Essen, Germany
| | - Martin W Hahn
- Research Department for Limnology, Universität Innsbruck, Mondsee, Austria
| | - Alexander J Probst
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research, University of Duisburg-Essen, Essen, Germany
| | - Daniela Beisser
- Department of Engineering and Natural Sciences, Westphalian University of Applied Science, Recklinghausen, Germany
- Centre for Water and Environmental Research, University of Duisburg-Essen, Essen, Germany
| | - Jens Boenigk
- Department of Biodiversity, University of Duisburg-Essen, Essen, Germany
- Centre for Water and Environmental Research, University of Duisburg-Essen, Essen, Germany
| |
Collapse
|
3
|
Hu H, Kristensen JM, Herbold CW, Pjevac P, Kitzinger K, Hausmann B, Dueholm MKD, Nielsen PH, Wagner M. Global abundance patterns, diversity, and ecology of Patescibacteria in wastewater treatment plants. MICROBIOME 2024; 12:55. [PMID: 38493180 PMCID: PMC10943839 DOI: 10.1186/s40168-024-01769-1] [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: 11/02/2023] [Accepted: 01/23/2024] [Indexed: 03/18/2024]
Abstract
BACKGROUND Microorganisms are responsible for nutrient removal and resource recovery in wastewater treatment plants (WWTPs), and their diversity is often studied by 16S rRNA gene amplicon sequencing. However, this approach underestimates the abundance and diversity of Patescibacteria due to the low coverage of commonly used PCR primers for this highly divergent bacterial phylum. Therefore, our current understanding of the global diversity, distribution, and ecological role of Patescibacteria in WWTPs is very incomplete. This is particularly relevant as Patescibacteria are considered to be associated with microbial host cells and can therefore influence the abundance and temporal variability of other microbial groups that are important for WWTP functioning. RESULTS Here, we evaluated the in silico coverage of widely used 16S rRNA gene-targeted primer pairs and redesigned a primer pair targeting the V4 region of bacterial and archaeal 16S rRNA genes to expand its coverage for Patescibacteria. We then experimentally evaluated and compared the performance of the original and modified V4-targeted primers on 565 WWTP samples from the MiDAS global sample collection. Using the modified primer pair, the percentage of ASVs classified as Patescibacteria increased from 5.9 to 23.8%, and the number of detected patescibacterial genera increased from 560 to 1576, while the detected diversity of the remaining microbial community remained similar. Due to this significantly improved coverage of Patescibacteria, we identified 23 core genera of Patescibacteria in WWTPs and described the global distribution pattern of these unusual microbes in these systems. Finally, correlation network analysis revealed potential host organisms that might be associated with Patescibacteria in WWTPs. Interestingly, strong indications were found for an association between Patescibacteria of the Saccharimonadia and globally abundant polyphosphate-accumulating organisms of the genus Ca. Phosphoribacter. CONCLUSIONS Our study (i) provides an improved 16S rRNA gene V4 region-targeted amplicon primer pair inclusive of Patescibacteria with little impact on the detection of other taxa, (ii) reveals the diversity and distribution patterns of Patescibacteria in WWTPs on a global scale, and (iii) provides new insights into the ecological role and potential hosts of Patescibacteria in WWTPs. Video Abstract.
Collapse
Affiliation(s)
- Huifeng Hu
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Universitätsring 1, 1010, Vienna, Austria
| | - Jannie Munk Kristensen
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Craig William Herbold
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
- Te Kura Putaiao Koiora, School of Biological Sciences, Te Whare Wananga o Waitaha, University of Canterbury, Otautahi, Christchurch, Aotearoa, New Zealand
| | - Petra Pjevac
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
- Joint Microbiome Facility of the Medical University of Vienna , University of Vienna, Vienna, Austria
| | - Katharina Kitzinger
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria
| | - Bela Hausmann
- Joint Microbiome Facility of the Medical University of Vienna , University of Vienna, Vienna, Austria
- Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Morten Kam Dahl Dueholm
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Per Halkjaer Nielsen
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Michael Wagner
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030, Vienna, Austria.
- Center for Microbial Communities, Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark.
- Joint Microbiome Facility of the Medical University of Vienna , University of Vienna, Vienna, Austria.
| |
Collapse
|
4
|
Layoun P, López-Pérez M, Haro-Moreno JM, Haber M, Thrash JC, Henson MW, Kavagutti VS, Ghai R, Salcher MM. Flexible genomic island conservation across freshwater and marine Methylophilaceae. THE ISME JOURNAL 2024; 18:wrad036. [PMID: 38365254 PMCID: PMC10872708 DOI: 10.1093/ismejo/wrad036] [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: 12/12/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 02/18/2024]
Abstract
The evolutionary trajectory of Methylophilaceae includes habitat transitions from freshwater sediments to freshwater and marine pelagial that resulted in genome reduction (genome-streamlining) of the pelagic taxa. However, the extent of genetic similarities in the genomic structure and microdiversity of the two genome-streamlined pelagic lineages (freshwater "Ca. Methylopumilus" and the marine OM43 lineage) has so far never been compared. Here, we analyzed complete genomes of 91 "Ca. Methylopumilus" strains isolated from 14 lakes in Central Europe and 12 coastal marine OM43 strains. The two lineages showed a remarkable niche differentiation with clear species-specific differences in habitat preference and seasonal distribution. On the other hand, we observed a synteny preservation in their genomes by having similar locations and types of flexible genomic islands (fGIs). Three main fGIs were identified: a replacement fGI acting as phage defense, an additive fGI harboring metabolic and resistance-related functions, and a tycheposon containing nitrogen-, thiamine-, and heme-related functions. The fGIs differed in relative abundances in metagenomic datasets suggesting different levels of variability ranging from strain-specific to population-level adaptations. Moreover, variations in one gene seemed to be responsible for different growth at low substrate concentrations and a potential biogeographic separation within one species. Our study provides a first insight into genomic microdiversity of closely related taxa within the family Methylophilaceae and revealed remarkably similar dynamics involving mobile genetic elements and recombination between freshwater and marine family members.
Collapse
Affiliation(s)
- Paul Layoun
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Mario López-Pérez
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, 03550 San Juan de Alicante, Spain
| | - Jose M Haro-Moreno
- Evolutionary Genomics Group, División de Microbiología, Universidad Miguel Hernández, 03550 San Juan de Alicante, Spain
| | - Markus Haber
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, 37005 Ceske Budejovice, Czech Republic
| | - J Cameron Thrash
- Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA
| | - Michael W Henson
- Department of Geophysical Sciences, University of Chicago, Chicago, IL 60637, USA
| | - Vinicius Silva Kavagutti
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, 37005 Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, 37005 Ceske Budejovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, 37005 Ceske Budejovice, Czech Republic
| | - Michaela M Salcher
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre CAS, 37005 Ceske Budejovice, Czech Republic
| |
Collapse
|
5
|
Man DKW, Hermans SM, Taubert M, Garcia SL, Hengoju S, Küsel K, Rosenbaum MA. Enrichment of different taxa of the enigmatic candidate phyla radiation bacteria using a novel picolitre droplet technique. ISME COMMUNICATIONS 2024; 4:ycae080. [PMID: 38946848 PMCID: PMC11214157 DOI: 10.1093/ismeco/ycae080] [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: 10/24/2023] [Revised: 03/24/2024] [Accepted: 06/20/2024] [Indexed: 07/02/2024]
Abstract
The candidate phyla radiation (CPR) represents a distinct monophyletic clade and constitutes a major portion of the tree of life. Extensive efforts have focused on deciphering the functional diversity of its members, primarily using sequencing-based techniques. However, cultivation success remains scarce, presenting a significant challenge, particularly in CPR-dominated groundwater microbiomes characterized by low biomass. Here, we employ an advanced high-throughput droplet microfluidics technique to enrich CPR taxa from groundwater. Utilizing a low-volume filtration approach, we successfully harvested a microbiome resembling the original groundwater microbial community. We assessed CPR enrichment in droplet and aqueous bulk cultivation for 30 days using a novel CPR-specific primer to rapidly track the CPR fraction through the cultivation attempts. The combination of soil extract and microbial-derived necromass provided the most supportive conditions for CPR enrichment. Employing these supplemented conditions, droplet cultivation proved superior to bulk cultivation, resulting in up to a 13-fold CPR enrichment compared to a 1- to 2-fold increase in bulk cultivation. Amplicon sequencing revealed 10 significantly enriched CPR orders. The highest enrichment in CPRs was observed for some unknown members of the Parcubacteria order, Cand. Jorgensenbacteria, and unclassified UBA9983. Furthermore, we identified co-enriched putative host taxa, which may guide more targeted CPR isolation approaches in subsequent investigations.
Collapse
Affiliation(s)
- DeDe Kwun Wai Man
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
- Balance of the Microverse, Cluster of Excellence, Friedrich Schiller University, 07743 Jena, Germany
| | - Syrie M Hermans
- Balance of the Microverse, Cluster of Excellence, Friedrich Schiller University, 07743 Jena, Germany
- Food Science and Microbiology, School of Science, Faculty of Health and Environmental Sciences, Auckland University of Technology, 1142 Auckland, New Zealand
- Aquatic Geomicrobiology, Institute of Biodiversity, Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany
| | - Martin Taubert
- Balance of the Microverse, Cluster of Excellence, Friedrich Schiller University, 07743 Jena, Germany
- Aquatic Geomicrobiology, Institute of Biodiversity, Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany
| | - Sarahi L Garcia
- Department of Ecology, Environment and Plant Sciences, Science for Life Laboratory, Stockholm University, 106 91 Stockholm, Sweden
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, 26129 Oldenburg, Germany
| | - Sundar Hengoju
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
| | - Kirsten Küsel
- Balance of the Microverse, Cluster of Excellence, Friedrich Schiller University, 07743 Jena, Germany
- Aquatic Geomicrobiology, Institute of Biodiversity, Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany
| | - Miriam A Rosenbaum
- Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (HKI), 07745 Jena, Germany
- Balance of the Microverse, Cluster of Excellence, Friedrich Schiller University, 07743 Jena, Germany
- Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University, 07743 Jena, Germany
| |
Collapse
|
6
|
Metze F, Vollmers J, Lenk F, Kaster AK. First shotgun metagenomics study of Juan de Fuca deep-sea sediments reveals distinct microbial communities above, within, between, and below sulfate methane transition zones. Front Microbiol 2023; 14:1241810. [PMID: 38053553 PMCID: PMC10694467 DOI: 10.3389/fmicb.2023.1241810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 10/03/2023] [Indexed: 12/07/2023] Open
Abstract
The marine deep subsurface is home to a vast microbial ecosystem, affecting biogeochemical cycles on a global scale. One of the better-studied deep biospheres is the Juan de Fuca (JdF) Ridge, where hydrothermal fluid introduces oxidants into the sediment from below, resulting in two sulfate methane transition zones (SMTZs). In this study, we present the first shotgun metagenomics study of unamplified DNA from sediment samples from different depths in this stratified environment. Bioinformatic analyses showed a shift from a heterotrophic, Chloroflexota-dominated community above the upper SMTZ to a chemolithoautotrophic Proteobacteria-dominated community below the secondary SMTZ. The reintroduction of sulfate likely enables respiration and boosts active cells that oxidize acetate, iron, and complex carbohydrates to degrade dead biomass in this low-abundance, low-diversity environment. In addition, analyses showed many proteins of unknown function as well as novel metagenome-assembled genomes (MAGs). The study provides new insights into microbial communities in this habitat, enabled by an improved DNA extraction protocol that allows a less biased view of taxonomic composition and metabolic activities, as well as uncovering novel taxa. Our approach presents the first successful attempt at unamplified shotgun sequencing samples from beyond 50 meters below the seafloor and opens new ways for capturing the true diversity and functional potential of deep-sea sediments.
Collapse
Affiliation(s)
| | | | | | - Anne-Kristin Kaster
- Institute for Biological Interfaces (IBG 5), Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz, Karlsruhe, Germany
| |
Collapse
|
7
|
Santana-Pereira ALR, Moen FS, Severance B, Liles MR. Influence of soil nutrients on the presence and distribution of CPR bacteria in a long-term crop rotation experiment. Front Microbiol 2023; 14:1114548. [PMID: 37577441 PMCID: PMC10413278 DOI: 10.3389/fmicb.2023.1114548] [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: 12/02/2022] [Accepted: 07/10/2023] [Indexed: 08/15/2023] Open
Abstract
Bacteria affiliated with the Candidate Phyla Radiation (CPR) are a hyper-diverse group of ultra-small bacteria with versatile yet sparse metabolisms. However, most insights into this group come from a surprisingly small number of environments, and recovery of CPR bacteria from soils has been hindered due to their extremely low abundance within complex microbial assemblages. In this study we enriched soil samples from 14 different soil fertility treatments for ultra-small (<0.45 μm) bacteria in order to study rare soil CPR. 42 samples were sequenced, enabling the reconstruction of 27 quality CPR metagenome-assembled genomes (MAGs) further classified as Parcubacteria/Paceibacteria, Saccharibacteria/Saccharimonadia and ABY1, in addition to representative genomes from Gemmatimonadetes, Dependentiae and Chlamydae phyla. These genomes were fully annotated and used to reconstruct the CPR community across all 14 plots. Additionally, for five of these plots, the entire microbiota was reconstructed using 16S amplification, showing that specific soil CPR may form symbiotic relationships with a varied and circumstantial range of hosts. Cullars CPR had a prevalence of enzymes predicted to degrade plant-derived carbohydrates, which suggests they have a role in plant biomass degradation. Parcubacteria appear to be more apt at microfauna necromass degradation. Cullars Saccharibacteria and a Parcubacteria group were shown to carry a possible aerotolerance mechanism coupled with potential for aerobic respiration, which appear to be a unique adaptation to the oxic soil environment. Reconstruction of CPR communities across treatment plots showed that they were not impacted by changes in nutrient levels or microbiota composition, being only impacted by extreme conditions, causing some CPR to dominate the community. These findings corroborate the understanding that soil-dwelling CPR bacteria have a very broad symbiont range and have metabolic capabilities associated to soil environments which allows them to scavenge resources and form resilient communities. The contributions of these microbial dark matter species to soil ecology and plant interactions will be of significant interest in future studies.
Collapse
Affiliation(s)
| | | | | | - Mark R. Liles
- Department of Biological Sciences, Auburn University, Auburn, AL, United States
| |
Collapse
|
8
|
Luo G, Liu M, Zeng J, Huang S, Huang J, Ahmed Z, Yang Y, Lai R, Xu D. Improvement of carbon source composition reduces antibiotic resistance genes in the ectopic fermentation system. BIORESOURCE TECHNOLOGY 2023; 380:129064. [PMID: 37068526 DOI: 10.1016/j.biortech.2023.129064] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/12/2023] [Accepted: 04/14/2023] [Indexed: 05/14/2023]
Abstract
Effectively reduce antibiotic resistance genes (ARGs) in ectopic fermentation system (EFS) is essential for practical production. In this study, three experiments were performed to explore how to remove ARGs in EFS effectively. Results demonstrated that ARGs were easily enriched in rice-husk-sawdust padding; simultaneous addition of laccase and cellulase suppressed the ARGs, mainly by increasing soluble carbohydrate concentration and promoting humic acid concentration; addition of corn stalks into rice-husk-sawdust decreased the abundance of ARGs by improving the carbon source structure and enhancing cellulase activity. In conclusion, the present study provides a guidance to reduce the threat of ARGs in EFS, which paved a potential pathway to safely utilize manure resources.
Collapse
Affiliation(s)
- Gan Luo
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Min Liu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Jinjie Zeng
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Shuntao Huang
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Jingshu Huang
- Agricultural Development Center of Hubei Province, Wuhan 430064, China
| | - Zulfiqar Ahmed
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Yaokun Yang
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Renhao Lai
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China
| | - Dequan Xu
- Colleges of Animal Science & Technology, Huazhong Agricultural University, Wuhan 430070, China; Frontiers Science Center for Animal Breeding and Sustainable Production, Wuhan 430070, China.
| |
Collapse
|
9
|
Maatouk M, Rolain JM, Bittar F. Using Genomics to Decipher the Enigmatic Properties and Survival Adaptation of Candidate Phyla Radiation. Microorganisms 2023; 11:1231. [PMID: 37317205 DOI: 10.3390/microorganisms11051231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 04/28/2023] [Accepted: 05/05/2023] [Indexed: 06/16/2023] Open
Abstract
Microbial ecology is a critical field for understanding the composition, diversity, and functions of microorganisms in various environmental and health-related processes. The discovery of Candidate Phyla Radiation (CPR) through culture-independent methods has introduced a new division of microbes characterized by a symbiotic/parasitic lifestyle, small cell size, and small genome. Despite being poorly understood, CPRs have garnered significant attention in recent years due to their widespread detection in a variety of environmental and clinical samples. These microorganisms have been found to exhibit a high degree of genetic diversity compared to other microbes. Several studies have shed light on their potential importance in global biogeochemical cycles and their impact on various human activities. In this review, we provide a systematic overview of the discovery of CPRs. We then focus on describing how the genomic characteristics of CPRs have helped them interact with and adapt to other microbes in different ecological niches. Future works should focus on discovering the metabolic capacities of CPRs and, if possible, isolating them to obtain a better understanding of these microorganisms.
Collapse
Affiliation(s)
- Mohamad Maatouk
- Aix-Marseille Université, IRD, APHM, MEPHI, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Jean-Marc Rolain
- Aix-Marseille Université, IRD, APHM, MEPHI, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| | - Fadi Bittar
- Aix-Marseille Université, IRD, APHM, MEPHI, 13005 Marseille, France
- IHU Méditerranée Infection, 13005 Marseille, France
| |
Collapse
|
10
|
Das S, Najar IN, Sherpa MT, Kumar S, Sharma P, Mondal K, Tamang S, Thakur N. Baseline metagenome-assembled genome (MAG) data of Sikkim hot springs from Indian Himalayan geothermal belt (IHGB) showcasing its potential CAZymes, and sulfur-nitrogen metabolic activity. World J Microbiol Biotechnol 2023; 39:179. [PMID: 37133792 DOI: 10.1007/s11274-023-03631-2] [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: 08/25/2022] [Accepted: 04/26/2023] [Indexed: 05/04/2023]
Abstract
Here we present the construction and characterization of metagenome assembled genomes (MAGs) from two hot springs residing in the vicinity of Indian Himalayan Geothermal Belt (IHGB). A total of 78 and 7 taxonomic bins were obtained for Old Yume Samdong (OYS) and New Yume Samdong (NYS) hot springs respectively. After passing all the criteria only 21 and 4 MAGs were further studied based on the successful prediction of their 16 S rRNA. Various databases were used such as GTDB, Kaiju, EzTaxon, BLAST XY Plot and NCBI BLAST to get the taxonomic classification of various 16 S rRNA predicted MAGs. The bacterial genomes found were from both thermophilic and mesophilic bacteria among which Proteobacteria, Chloroflexi, Bacteroidetes and Firmicutes were the abundant phyla. However, in case of OYS, two genomes belonged to archaeal Methanobacterium and Methanocaldococcus. Functional characterization revealed the richness of CAZymes such as Glycosyl Transferase (GT) (56.7%), Glycoside Hydrolase (GH) (37.4%), Carbohydrate Esterase family (CE) (8.2%), and Polysaccharide Lyase (PL) (1.9%). There were negligible antibiotic resistance genes in the MAGs however, a significant heavy metal tolerance gene was found in the MAGs. Thus, it may be assumed that there is no coexistence of antibiotic and heavy metal resistance genes in these hot spring microbiomes. Since the selected hot springs possess good sulfur content thus, we also checked the presence of genes for sulfur and nitrogen metabolism. It was found that MAGs from both the hot springs possess significant number of genes related to sulfur and nitrogen metabolism.
Collapse
Affiliation(s)
- Sayak Das
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
- Department of Life Science and Bioinformatics, Hargobind Khurana School of Life Sciences, Assam University, Silchar, Assam, 788011, India
| | - Ishfaq Nabi Najar
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
| | - Mingma Thundu Sherpa
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
| | - Santosh Kumar
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
| | - Prayatna Sharma
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
| | - Krishnendu Mondal
- Department of Microbiology, Vidyasagar University, Midnapore, West Bengal, 721102, India
| | - Sonia Tamang
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India
| | - Nagendra Thakur
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Gangtok, Sikkim, 737102, India.
| |
Collapse
|
11
|
Wang Y, Zhang Y, Hu Y, Liu L, Liu SJ, Zhang T. Genome-centric metagenomics reveals the host-driven dynamics and ecological role of CPR bacteria in an activated sludge system. MICROBIOME 2023; 11:56. [PMID: 36945052 PMCID: PMC10031880 DOI: 10.1186/s40168-023-01494-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 02/14/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND Candidate phyla radiation (CPR) constitutes highly diverse bacteria with small cell sizes and are likely obligate intracellular symbionts. Given their distribution and complex associations with bacterial hosts, genetic and biological features of CPR bacteria in low-nutrient environments have received increasing attention. However, CPR bacteria in wastewater treatment systems remain poorly understood. We utilized genome-centric metagenomics to answer how CPR communities shift over 11 years and what kind of ecological roles they act in an activated sludge system. RESULTS We found that approximately 9% (135) of the 1,526 non-redundant bacterial and archaeal metagenome-assembled genomes were affiliated with CPR. CPR bacteria were consistently abundant with a relative abundance of up to 7.5% in the studied activated sludge system. The observed striking fluctuations in CPR community compositions and the limited metabolic and biosynthetic capabilities in CPR bacteria collectively revealed the nature that CPR dynamics may be directly determined by the available hosts. Similarity-based network analysis further confirmed the broad bacterial hosts of CPR lineages. The proteome contents of activated sludge-associated CPR had a higher similarity to those of environmental-associated CPR than to those of human-associated ones. Comparative genomic analysis observed significant enrichment of genes for oxygen stress resistance in activated sludge-associated CPR bacteria. Furthermore, genes for carbon cycling and horizontal gene transfer were extensively identified in activated sludge-associated CPR genomes. CONCLUSIONS These findings highlight the presence of specific host interactions among CPR lineages in activated sludge systems. Despite the lack of key metabolic pathways, these small, yet abundant bacteria may have significant involvements in biogeochemical cycling and bacterial evolution in activated sludge systems. Video Abstract.
Collapse
Affiliation(s)
- Yulin Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Yulin Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Yu Hu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
| | - Lei Liu
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| | - Shuang-Jiang Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266000 People’s Republic of China
| | - Tong Zhang
- Environmental Microbiome Engineering and Biotechnology Laboratory, The University of Hong Kong, Hong Kong, People’s Republic of China
| |
Collapse
|
12
|
Chiriac MC, Haber M, Salcher MM. Adaptive genetic traits in pelagic freshwater microbes. Environ Microbiol 2023; 25:606-641. [PMID: 36513610 DOI: 10.1111/1462-2920.16313] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022]
Abstract
Pelagic microbes have adopted distinct strategies to inhabit the pelagial of lakes and oceans and can be broadly categorized in two groups: free-living, specialized oligotrophs and patch-associated generalists or copiotrophs. In this review, we aim to identify genomic traits that enable pelagic freshwater microbes to thrive in their habitat. To do so, we discuss the main genetic differences of pelagic marine and freshwater microbes that are both dominated by specialized oligotrophs and the difference to freshwater sediment microbes, where copiotrophs are more prevalent. We phylogenomically analysed a collection of >7700 metagenome-assembled genomes, classified habitat preferences on different taxonomic levels, and compared the metabolic traits of pelagic freshwater, marine, and freshwater sediment microbes. Metabolic differences are mainly associated with transport functions, environmental information processing, components of the electron transport chain, osmoregulation and the isoelectric point of proteins. Several lineages with known habitat transitions (Nitrososphaeria, SAR11, Methylophilaceae, Synechococcales, Flavobacteriaceae, Planctomycetota) and the underlying mechanisms in this process are discussed in this review. Additionally, the distribution, ecology and genomic make-up of the most abundant freshwater prokaryotes are described in details in separate chapters for Actinobacteriota, Bacteroidota, Burkholderiales, Verrucomicrobiota, Chloroflexota, and 'Ca. Patescibacteria'.
Collapse
Affiliation(s)
| | - Markus Haber
- Institute of Hydrobiology, Biology Centre CAS, Ceske Budejovice, Czechia
| | - Michaela M Salcher
- Institute of Hydrobiology, Biology Centre CAS, Ceske Budejovice, Czechia
| |
Collapse
|
13
|
Haro-Moreno JM, Cabello-Yeves PJ, Garcillán-Barcia MP, Zakharenko A, Zemskaya TI, Rodriguez-Valera F. A novel and diverse group of Candidatus Patescibacteria from bathypelagic Lake Baikal revealed through long-read metagenomics. ENVIRONMENTAL MICROBIOME 2023; 18:12. [PMID: 36823661 PMCID: PMC9948471 DOI: 10.1186/s40793-023-00473-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 02/21/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND Lake Baikal, the world's deepest freshwater lake, contains important numbers of Candidatus Patescibacteria (formerly CPR) in its deepest reaches. However, previously obtained CPR metagenome-assembled genomes recruited very poorly indicating the potential of other groups being present. Here, we have applied for the first time a long-read (PacBio CCS) metagenomic approach to analyze in depth the Ca. Patescibacteria living in the bathypelagic water column of Lake Baikal at 1600 m. RESULTS The retrieval of nearly complete 16S rRNA genes before assembly has allowed us to detect the presence of a novel and a likely endemic group of Ca. Patescibacteria inhabiting bathypelagic Lake Baikal. This novel group seems to possess extremely high intra-clade diversity, precluding complete genomes' assembly. However, read binning and scaffolding indicate that these microbes are similar to other Ca. Patescibacteria (i.e. parasites or symbionts), although they seem to carry more anabolic pathways, likely reflecting the extremely oligotrophic habitat they inhabit. The novel bins have not been found anywhere, but one of the groups appears in small amounts in an oligotrophic and deep alpine Lake Thun. We propose this novel group be named Baikalibacteria. CONCLUSION The recovery of 16S rRNA genes via long-read metagenomics plus the use of long-read binning to uncover highly diverse "hidden" groups of prokaryotes are key strategies to move forward in ecogenomic microbiology. The novel group possesses enormous intraclade diversity akin to what happens with Ca. Patescibacteria at the interclade level, which is remarkable in an environment that has changed little in the last 25 million years.
Collapse
Affiliation(s)
- Jose M Haro-Moreno
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan de Alicante, 03550, Alicante, Spain
| | - Pedro J Cabello-Yeves
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 46980, Paterna, Valencia, Spain
| | - M Pilar Garcillán-Barcia
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Spain
| | - Alexandra Zakharenko
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - Tamara I Zemskaya
- Limnological Institute, Siberian Branch of the Russian Academy of Sciences, Irkutsk, Russia
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Apartado 18, San Juan de Alicante, 03550, Alicante, Spain.
| |
Collapse
|
14
|
Roda-Garcia JJ, Haro-Moreno JM, Rodriguez-Valera F, Almagro-Moreno S, López-Pérez M. Single-amplified genomes reveal most streamlined free-living marine bacteria. Environ Microbiol 2023. [PMID: 36755376 DOI: 10.1111/1462-2920.16348] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 02/04/2023] [Indexed: 02/10/2023]
Abstract
Evolutionary adaptations of prokaryotes to the environment sometimes result in genome reduction. Our knowledge of this phenomenon among free-living bacteria remains scarce. We address the dynamics and limits of genome reduction by examining one of the most abundant bacteria in the ocean, the SAR86 clade. Despite its abundance, comparative genomics has been limited by the absence of pure cultures and the poor representation in metagenome-assembled genomes. We co-assembled multiple previously available single-amplified genomes to obtain the first complete genomes from members of the four families. All families showed a convergent evolutionary trajectory with characteristic features of streamlined genomes, most pronounced in the TMED112 family. This family has a genome size of ca. 1 Mb and only 1 bp as median intergenic distance, exceeding values found in other abundant microbes such as SAR11, OM43 and Prochlorococcus. This genomic simplification led to a reduction in the biosynthesis of essential molecules, DNA repair-related genes, and the ability to sense and respond to environmental factors, which could suggest an evolutionary dependence on other co-occurring microbes for survival (Black Queen hypothesis). Therefore, these reconstructed genomes within the SAR86 clade provide new insights into the limits of genome reduction in free-living marine bacteria.
Collapse
Affiliation(s)
- Juan J Roda-Garcia
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Jose M Haro-Moreno
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| | - Salvador Almagro-Moreno
- Burnett School of Biomedical Sciences, University of Central Florida, Orlando, Florida, USA.,National Center for Integrated Coastal Research, University of Central Florida, Orlando, Florida, USA
| | - Mario López-Pérez
- Evolutionary Genomics Group, Departamento Producción Vegetal y Microbiología, Universidad Miguel Hernández, Alicante, Spain
| |
Collapse
|
15
|
Vigneron A, Cruaud P, Guyoneaud R, Goñi-Urriza M. Into the darkness of the microbial dark matter in situ activities through expression profiles of Patescibacteria populations. Front Microbiol 2023; 13:1073483. [PMID: 36699594 PMCID: PMC9868632 DOI: 10.3389/fmicb.2022.1073483] [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: 10/18/2022] [Accepted: 12/05/2022] [Indexed: 01/11/2023] Open
Abstract
Patescibacteria form a highly diverse and widespread superphylum of uncultured microorganisms representing a third of the global microbial diversity. Most of our knowledge on Patescibacteria putative physiology relies on metagenomic mining and metagenome-assembled genomes, but the in situ activities and the ecophysiology of these microorganisms have been rarely explored, leaving the role of Patescibacteria in ecosystems elusive. Using a genome-centric metatranscriptomic approach, we analyzed the diel and seasonal gene transcription profiles of 18 Patescibacteria populations in brackish microbial mats to test whether our understanding of Patescibacteria metabolism allows the extrapolation of their in situ activities. Although our results revealed a circadian cycle in Patescibacteria activities, a strong streamlined genetic expression characterized the Patescibacteria populations. This result has a major consequence for the extrapolation of their physiology and environmental function since most transcribed genes were uncharacterized, indicating that the ecophysiology of Patescibacteria cannot be yet reliably predicted from genomic data.
Collapse
Affiliation(s)
- Adrien Vigneron
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| | | | - Rémy Guyoneaud
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| | - Marisol Goñi-Urriza
- IBEAS, Université de Pau et des Pays de l'Adour, E2S UPPA, CNRS, IPREM, Pau, France
| |
Collapse
|
16
|
Zhao R, Farag IF, Jørgensen SL, Biddle JF. Occurrence, Diversity, and Genomes of " Candidatus Patescibacteria" along the Early Diagenesis of Marine Sediments. Appl Environ Microbiol 2022; 88:e0140922. [PMID: 36468881 PMCID: PMC9765117 DOI: 10.1128/aem.01409-22] [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] [Received: 08/17/2022] [Accepted: 11/14/2022] [Indexed: 12/07/2022] Open
Abstract
The phylum "Candidatus Patescibacteria" (or Candidate Phyla Radiation [CPR]) accounts for roughly one-quarter of microbial diversity on Earth, but the presence and diversity of these bacteria in marine sediments have been rarely charted. Here, we investigate the abundance, diversity, and metabolic capacities of CPR bacteria in three sediment sites (Mohns Ridge, North Pond, and Costa Rica Margin) with samples covering a wide range of redox zones formed during the early diagenesis of organic matter. Through metagenome sequencing, we found that all investigated sediment horizons contain "Ca. Patescibacteria" (0.4 to 28% of the total communities), which are affiliated with the classes "Ca. Paceibacteria," "Ca. Gracilibacteria," "Ca. Microgenomatia," "Ca. Saccharimonadia," "Ca. ABY1," and "Ca. WWE3." However, only a subset of the diversity of marine sediment "Ca. Patescibacteria," especially the classes "Ca. Paceibacteria" and "Ca. Gracilibacteria," can be captured by 16S rRNA gene amplicon sequencing with commonly used universal primers. We recovered 11 metagenome-assembled genomes (MAGs) of CPR from these sediments, most of which are novel at the family or genus level in the "Ca. Paceibacteria" class and are missed by the amplicon sequencing. While individual MAGs are confined to specific anoxic niches, the lack of capacities to utilize the prevailing terminal electron acceptors indicates that they may not be directly selected by the local redox conditions. These CPR bacteria lack essential biosynthesis pathways and may use a truncated glycolysis pathway to conserve energy as fermentative organotrophs. Our findings suggest that marine sediments harbor some novel yet widespread CPR bacteria during the early diagenesis of organic matter, which needs to be considered in population dynamics assessments in this vast environment. IMPORTANCE Ultrasmall-celled "Ca. Patescibacteria" have been estimated to account for one-quarter of the total microbial diversity on Earth, the parasitic lifestyle of which may exert a profound control on the overall microbial population size of the local ecosystems. However, their diversity and metabolic functions in marine sediments, one of the largest yet understudied ecosystems on Earth, remain virtually uncharacterized. By applying cultivation-independent approaches to a range of sediment redox zones, we reveal that "Ca. Patescibacteria" members are rare but widespread regardless of the prevailing geochemical conditions. These bacteria are affiliated with novel branches of "Ca. Patescibacteria" and have been largely missed in marker gene-based surveys. They do not have respiration capacity but may conserve energy by fermenting organic compounds from their episymbiotic hosts. Our findings suggest that these novel "Ca. Patescibacteria" are among the previously overlooked microbes in diverse marine sediments.
Collapse
Affiliation(s)
- Rui Zhao
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Ibrahim F. Farag
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
| | - Steffen L. Jørgensen
- Centre for Deep Sea Research, Department of Earth Science, University of Bergen, Bergen, Norway
| | - Jennifer F. Biddle
- School of Marine Science and Policy, University of Delaware, Lewes, Delaware, USA
| |
Collapse
|
17
|
Ji Y, Zhang P, Zhou S, Gao P, Wang B, Jiang J. Widespread but Poorly Understood Bacteria: Candidate Phyla Radiation. Microorganisms 2022; 10:2232. [PMID: 36422302 PMCID: PMC9698310 DOI: 10.3390/microorganisms10112232] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 08/15/2023] Open
Abstract
Candidate Phyla Radiation (CPR) bacteria is a bacterial division composed mainly of candidate phyla bacteria with ultra-small cell sizes, streamlined genomes, and limited metabolic capacity, which are generally considered to survive in a parasitic or symbiotic manner. Despite their wide distribution and rich diversity, CPR bacteria have received little attention until recent years, and are therefore poorly understood. This review systematically summarizes the history of CPR research, the parasitic/symbiotic lifestyle, and the ecological distribution and unique metabolic features of CPR bacteria, hoping to provide guidance for future ecological and physiological research on CPR bacteria.
Collapse
Affiliation(s)
| | | | | | | | - Baozhan Wang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, Nanjing 210095, China
| | - Jiandong Jiang
- Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, Nanjing 210095, China
| |
Collapse
|
18
|
Briddon CL, Szekeres E, Hegedüs A, Nicoară M, Chiriac C, Stockenreiter M, Drugă B. The combined impact of low temperatures and shifting phosphorus availability on the competitive ability of cyanobacteria. Sci Rep 2022; 12:16409. [PMID: 36180771 PMCID: PMC9525609 DOI: 10.1038/s41598-022-20580-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
In freshwater systems, cyanobacteria are strong competitors under enhanced temperature and eutrophic conditions. Understanding their adaptive and evolutionary potential to multiple environmental states allows us to accurately predict their response to future conditions. To better understand if the combined impacts of temperature and nutrient limitation could suppress the cyanobacterial blooms, a single strain of Microcystis aeruginosa was inoculated into natural phytoplankton communities with different nutrient conditions: oligotrophic, eutrophic and eutrophic with the addition of bentophos. We found that the use of the bentophos treatment causes significant differences in prokaryotic and eukaryotic communities. This resulted in reduced biodiversity among the eukaryotes and a decline in cyanobacterial abundance suggesting phosphorus limitation had a strong impact on the community structure. The low temperature during the experiment lead to the disappearance of M. aeruginosa in all treatments and gave other phytoplankton groups a competitive advantage leading to the dominance of the eukaryotic families that have diverse morphologies and nutritional modes. These results show cyanobacteria have a reduced competitive advantage under certain temperature and nutrient limiting conditions and therefore, controlling phosphorus concentrations could be a possible mitigation strategy for managing harmful cyanobacterial blooms in a future warmer climate.
Collapse
Affiliation(s)
- Charlotte L Briddon
- Institute of Biological Research (NIRDBS), 48 Republicii Street, 400015, Cluj-Napoca, Romania
| | - Edina Szekeres
- Institute of Biological Research (NIRDBS), 48 Republicii Street, 400015, Cluj-Napoca, Romania
| | - Adriana Hegedüs
- Institute of Biological Research (NIRDBS), 48 Republicii Street, 400015, Cluj-Napoca, Romania
| | - Maria Nicoară
- Institute of Biological Research (NIRDBS), 48 Republicii Street, 400015, Cluj-Napoca, Romania
| | - Cecilia Chiriac
- Biology Centre of the Czech Academy of Sciences, Institute of Hydrobiology, 37005, České Budějovice, Czech Republic
| | - Maria Stockenreiter
- Department of Biology II, Experimental Aquatic Ecology, Ludwig-Maximilians-Universitӓt Müchen, Groβhaderner Str. 2, 82152, Planegg-Martinsried, Germany
| | - Bogdan Drugă
- Institute of Biological Research (NIRDBS), 48 Republicii Street, 400015, Cluj-Napoca, Romania.
| |
Collapse
|
19
|
Long-Read-Resolved, Ecosystem-Wide Exploration of Nucleotide and Structural Microdiversity of Lake Bacterioplankton Genomes. mSystems 2022; 7:e0043322. [PMID: 35938717 PMCID: PMC9426551 DOI: 10.1128/msystems.00433-22] [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] [Indexed: 12/24/2022] Open
Abstract
Reconstruction of metagenome-assembled genomes (MAGs) has become a fundamental approach in microbial ecology. However, a MAG is hardly complete and overlooks genomic microdiversity because metagenomic assembly fails to resolve microvariants among closely related genotypes. Aiming at understanding the universal factors that drive or constrain prokaryotic genome diversification, we performed an ecosystem-wide high-resolution metagenomic exploration of microdiversity by combining spatiotemporal (2 depths × 12 months) sampling from a pelagic freshwater system, high-quality MAG reconstruction using long- and short-read metagenomic sequences, and profiling of single nucleotide variants (SNVs) and structural variants (SVs) through mapping of short and long reads to the MAGs, respectively. We reconstructed 575 MAGs, including 29 circular assemblies, providing high-quality reference genomes of freshwater bacterioplankton. Read mapping against these MAGs identified 100 to 101,781 SNVs/Mb and 0 to 305 insertions, 0 to 467 deletions, 0 to 41 duplications, and 0 to 6 inversions for each MAG. Nonsynonymous SNVs were accumulated in genes potentially involved in cell surface structural modification to evade phage recognition. Most (80.2%) deletions overlapped with a gene coding region, and genes of prokaryotic defense systems were most frequently (>8% of the genes) overlapped with a deletion. Some such deletions exhibited a monthly shift in their allele frequency, suggesting a rapid turnover of genotypes in response to phage predation. MAGs with extremely low microdiversity were either rare or opportunistic bloomers, suggesting that population persistency is key to their genomic diversification. The results concluded that prokaryotic genomic diversification is driven primarily by viral load and constrained by a population bottleneck. IMPORTANCE Identifying intraspecies genomic diversity (microdiversity) is crucial to understanding microbial ecology and evolution. However, microdiversity among environmental assemblages is not well investigated, because most microbes are difficult to culture. In this study, we performed cultivation-independent exploration of bacterial genomic microdiversity in a lake ecosystem using a combination of short- and long-read metagenomic analyses. The results revealed the broad spectrum of genomic microdiversity among the diverse bacterial species in the ecosystem, which has been overlooked by conventional approaches. Our ecosystem-wide exploration further allowed comparative analysis among the genomes and genes and revealed factors behind microbial genomic diversification, namely, that diversification is driven primarily by resistance against viral infection and constrained by the population size.
Collapse
|