151
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Wang M, Noor S, Huan R, Liu C, Li J, Shi Q, Zhang YJ, Wu C, He H. Comparison of the diversity of cultured and total bacterial communities in marine sediment using culture-dependent and sequencing methods. PeerJ 2020; 8:e10060. [PMID: 33150062 PMCID: PMC7585373 DOI: 10.7717/peerj.10060] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 09/07/2020] [Indexed: 12/22/2022] Open
Abstract
Despite recent great advances in microbial culture, most microbes have not yet been cultured, and the impact of medium composition on the isolation of microbes from natural systems has not been elucidated. To optimize media for culturing marine microbes, microbial communities in three sediment samples were described using high-throughput sequencing (HTS) and culture-dependent techniques. HTS revealed communities dominated by Gammaproteobacteria, and culture-based methods revealed communities dominated by Actinobacteria. Among the total operational taxonomic units (OTUs) from the HTS dataset, 6% were recovered in the culture collection. Four potentially novel bacterial strains belonging to Oceaniovalibus, Psychrobacter and Salegentibacter were isolated. The combination of media cultured more taxa than any single medium. Nutrient-rich and single-carbon/nitrogen-source media supported the growth of relatively few taxa, and the quality of nitrogen strongly influenced the types of bacteria isolated.
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Affiliation(s)
- Meng Wang
- School of Life Science, Central South University, Changsha, China
| | - Samina Noor
- School of Life Science, Central South University, Changsha, China
| | - Ran Huan
- School of Life Science, Central South University, Changsha, China
| | - Congling Liu
- School of Life Science, Central South University, Changsha, China
| | - JiaYi Li
- School of Life Science, Central South University, Changsha, China
| | - Qingxin Shi
- School of Life Science, Central South University, Changsha, China
| | | | - Cuiling Wu
- Changzhi Medical College, Changzhi, China
| | - Hailun He
- School of Life Science, Central South University, Changsha, China
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152
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A network approach to elucidate and prioritize microbial dark matter in microbial communities. ISME JOURNAL 2020; 15:228-244. [PMID: 32963345 PMCID: PMC7852563 DOI: 10.1038/s41396-020-00777-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/18/2020] [Accepted: 09/10/2020] [Indexed: 01/13/2023]
Abstract
Microbes compose most of the biomass on the planet, yet the majority of taxa remain uncharacterized. These unknown microbes, often referred to as “microbial dark matter,” represent a major challenge for biology. To understand the ecological contributions of these Unknown taxa, it is essential to first understand the relationship between unknown species, neighboring microbes, and their respective environment. Here, we establish a method to study the ecological significance of “microbial dark matter” by building microbial co-occurrence networks from publicly available 16S rRNA gene sequencing data of four extreme aquatic habitats. For each environment, we constructed networks including and excluding unknown organisms at multiple taxonomic levels and used network centrality measures to quantitatively compare networks. When the Unknown taxa were excluded from the networks, a significant reduction in degree and betweenness was observed for all environments. Strikingly, Unknown taxa occurred as top hubs in all environments, suggesting that “microbial dark matter” play necessary ecological roles within their respective communities. In addition, novel adaptation-related genes were detected after using 16S rRNA gene sequences from top-scoring hub taxa as probes to blast metagenome databases. This work demonstrates the broad applicability of network metrics to identify and prioritize key Unknown taxa and improve understanding of ecosystem structure across diverse habitats.
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153
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Evidence for a Growth Zone for Deep-Subsurface Microbial Clades in Near-Surface Anoxic Sediments. Appl Environ Microbiol 2020; 86:AEM.00877-20. [PMID: 32709727 DOI: 10.1128/aem.00877-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 07/17/2020] [Indexed: 11/20/2022] Open
Abstract
Global marine sediments harbor a large and highly diverse microbial biosphere, but the mechanism by which this biosphere is established during sediment burial is largely unknown. During burial in marine sediments, concentrations of easily metabolized organic compounds and total microbial cell abundance decrease. However, it is unknown whether some microbial clades increase with depth. We show total population increases in 38 microbial families over 3 cm of sediment depth in the upper 7.5 cm of White Oak River (WOR) estuary sediments. Clades that increased with depth were more often associated with one or more of the following: anaerobes, uncultured, or common in deep marine sediments relative to those that decreased. Maximum doubling times (in situ steady-state growth rates could be faster to balance cell decay) were estimated as 2 to 25 years by combining sedimentation rate with either quantitative PCR (qPCR) or the product of the fraction read abundance of 16S rRNA genes and total cell counts (FRAxC). Doubling times were within an order of magnitude of each other in two adjacent cores, as well as in two laboratory enrichments of Cape Lookout Bight (CLB), NC, sediments (average difference of 28% ± 19%). qPCR and FRAxC in sediment cores and laboratory enrichments produced similar doubling times for key deep subsurface uncultured clades Bathyarchaeota (8.7 ± 1.9 years) and Thermoprofundales/MBG-D (4.1 ± 0.7 years). We conclude that common deep subsurface microbial clades experience a narrow zone of growth in shallow sediments, offering an opportunity for selection of long-term subsistence traits after resuspension events.IMPORTANCE Many studies show that the uncultured microbes that dominate global marine sediments do not actually increase in population size as they are buried in marine sediments; rather, they exist in a sort of prolonged torpor for thousands of years. This is because, although studies have shown biomass turnover in these clades, no evidence has ever been found that deeper sediments have larger populations for specific clades than shallower layers. We discovered that they actually do increase population sizes during burial, but only in the upper few centimeters. This suggests that marine sediments may be a vast repository of mostly nongrowing microbes with a thin and relatively rapid area of cell abundance increase in the upper 10 cm, offering a chance for subsurface organisms to undergo natural selection.
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154
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Wong HL, MacLeod FI, White RA, Visscher PT, Burns BP. Microbial dark matter filling the niche in hypersaline microbial mats. MICROBIOME 2020; 8:135. [PMID: 32938503 PMCID: PMC7495880 DOI: 10.1186/s40168-020-00910-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Accepted: 08/19/2020] [Indexed: 05/08/2023]
Abstract
BACKGROUND Shark Bay, Australia, harbours one of the most extensive and diverse systems of living microbial mats that are proposed to be analogs of some of the earliest ecosystems on Earth. These ecosystems have been shown to possess a substantial abundance of uncultivable microorganisms. These enigmatic microbes, jointly coined as 'microbial dark matter' (MDM), are hypothesised to play key roles in modern microbial mats. RESULTS We reconstructed 115 metagenome-assembled genomes (MAGs) affiliated to MDM, spanning 42 phyla. This study reports for the first time novel microorganisms (Zixibacterial order GN15) putatively taking part in dissimilatory sulfate reduction in surface hypersaline settings, as well as novel eukaryote signature proteins in the Asgard archaea. Despite possessing reduced-size genomes, the MDM MAGs are capable of fermenting and degrading organic carbon, suggesting a role in recycling organic carbon. Several forms of RuBisCo were identified, allowing putative CO2 incorporation into nucleotide salvaging pathways, which may act as an alternative carbon and phosphorus source. High capacity of hydrogen production was found among Shark Bay MDM. Putative schizorhodopsins were also identified in Parcubacteria, Asgard archaea, DPANN archaea, and Bathyarchaeota, allowing these members to potentially capture light energy. Diversity-generating retroelements were prominent in DPANN archaea that likely facilitate the adaptation to a dynamic, host-dependent lifestyle. CONCLUSIONS This is the first study to reconstruct and describe in detail metagenome-assembled genomes (MAGs) affiliated with microbial dark matter in hypersaline microbial mats. Our data suggests that these microbial groups are major players in these systems. In light of our findings, we propose H2, ribose and CO/CO2 as the main energy currencies of the MDM community in these mat systems. Video Abstract.
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Affiliation(s)
- Hon Lun Wong
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Fraser I MacLeod
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
| | - Richard Allen White
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- RAW Molecular Systems LLC, Spokane, WA, USA
- Department of Bioinformatics and Genomics, The University of North Carolina, Charlotte, NC, USA
| | - Pieter T Visscher
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia
- Department of Marine Sciences, University of Connecticut, Mansfield, USA
- Biogeosciences, the Université de Bourgogne Franche-Comté, Dijon, France
| | - Brendan P Burns
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, 2052, Australia.
- Australian Centre for Astrobiology, University of New South Wales, Sydney, Australia.
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155
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Discovering the indigenous microbial communities associated with the natural fermentation of sap from the cider gum Eucalyptus gunnii. Sci Rep 2020; 10:14716. [PMID: 32895409 PMCID: PMC7477236 DOI: 10.1038/s41598-020-71663-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 08/19/2020] [Indexed: 12/13/2022] Open
Abstract
Over the course of human history and in most societies, fermented beverages have had a unique economic and cultural importance. Before the arrival of the first Europeans in Australia, Aboriginal people reportedly produced several fermented drinks including mangaitch from flowering cones of Banksia and way-a-linah from Eucalyptus tree sap. In the case of more familiar fermented beverages, numerous microorganisms, including fungi, yeast and bacteria, present on the surface of fruits and grains are responsible for the conversion of the sugars in these materials into ethanol. Here we describe native microbial communities associated with the spontaneous fermentation of sap from the cider gum Eucalyptus gunnii, a Eucalyptus tree native to the remote Central Plateau of Tasmania. Amplicon-based phylotyping showed numerous microbial species in cider gum samples, with fungal species differing greatly to those associated with winemaking. Phylotyping also revealed several fungal sequences which do not match known fungal genomes suggesting novel yeast species. These findings highlight the vast microbial diversity associated with the Australian Eucalyptus gunnii and the native alcoholic beverage way-a-linah.
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156
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Espina L. An approach to increase the success rate of cultivation of soil bacteria based on fluorescence-activated cell sorting. PLoS One 2020; 15:e0237748. [PMID: 32866195 PMCID: PMC7458294 DOI: 10.1371/journal.pone.0237748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 07/31/2020] [Indexed: 12/05/2022] Open
Abstract
Soil microbiota are considered a source of undiscovered bioactive compounds, yet cultivation of most bacteria within a sample remains generally unsuccessful. Two main reasons behind the unculturability of bacteria are the presence of cells in a viable but not culturable state (such as dormant cells) and the failure to provide the necessary growth requirements in vitro (leading to the classification of some bacterial taxa as yet-to-be-cultured). The present work focuses on the development of a single procedure that helps distinguish between both phenomena of unculturability based on viability staining coupled with flow cytometry and fluorescence-activated cell sorting. In the selected soil sample, the success rate of cultured bacteria was doubled by selecting viable and metabolically active bacteria. It was determined that most of the uncultured fraction was not dormant or dead but likely required different growth conditions. It was also determined that the staining process introduced changes in the taxonomic composition of the outgrown bacterial biomass, which should be considered for further developments. This research shows the potential of flow cytometry and fluorescence-activated cell sorting applied to soil samples to improve the success rate of bacterial cultivation by estimating the proportion of dormant and yet-to-be-cultured bacteria and by directly excluding dormant cells from being inoculated into growth media.
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Affiliation(s)
- Laura Espina
- Department of Medical Microbiology, Cardiff University, Cardiff, United Kingdom
- * E-mail:
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157
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Jurburg SD, Konzack M, Eisenhauer N, Heintz-Buschart A. The archives are half-empty: an assessment of the availability of microbial community sequencing data. Commun Biol 2020; 3:474. [PMID: 32859925 PMCID: PMC7455719 DOI: 10.1038/s42003-020-01204-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/03/2020] [Indexed: 02/07/2023] Open
Abstract
As DNA sequencing has become more popular, the public genetic repositories where sequences are archived have experienced explosive growth. These repositories now hold invaluable collections of sequences, e.g., for microbial ecology, but whether these data are reusable has not been evaluated. We assessed the availability and state of 16S rRNA gene amplicon sequences archived in public genetic repositories (SRA, EBI, and DDJ). We screened 26,927 publications in 17 microbiology journals, identifying 2015 16S rRNA gene sequencing studies. Of these, 7.2% had not made their data public at the time of analysis. Among a subset of 635 studies sequencing the same gene region, 40.3% contained data which was not available or not reusable, and an additional 25.5% contained faults in data formatting or data labeling, creating obstacles for data reuse. Our study reveals gaps in data availability, identifies major contributors to data loss, and offers suggestions for improving data archiving practices.
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Affiliation(s)
- Stephanie D Jurburg
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany.
- Leipzig University, Institute of Biology, Deutscher Platz 5e, 04103, Leipzig, Germany.
| | - Maximilian Konzack
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany
- Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Nico Eisenhauer
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany
- Leipzig University, Institute of Biology, Deutscher Platz 5e, 04103, Leipzig, Germany
| | - Anna Heintz-Buschart
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, 04103, Leipzig, Germany
- Helmholtz Centre for Environmental Research GmbH - UFZ, Halle, Germany
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158
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Microbial single-cell omics: the crux of the matter. Appl Microbiol Biotechnol 2020; 104:8209-8220. [PMID: 32845367 PMCID: PMC7471194 DOI: 10.1007/s00253-020-10844-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/08/2020] [Accepted: 08/17/2020] [Indexed: 01/10/2023]
Abstract
Abstract Single-cell genomics and transcriptomics can provide reliable context for assembled genome fragments and gene expression activity on the level of individual prokaryotic genomes. These methods are rapidly emerging as an essential complement to cultivation-based, metagenomics, metatranscriptomics, and microbial community-focused research approaches by allowing direct access to information from individual microorganisms, even from deep-branching phylogenetic groups that currently lack cultured representatives. Their integration and binning with environmental ‘omics data already provides unprecedented insights into microbial diversity and metabolic potential, enabling us to provide information on individual organisms and the structure and dynamics of natural microbial populations in complex environments. This review highlights the pitfalls and recent advances in the field of single-cell omics and its importance in microbiological and biotechnological studies. Key points • Single-cell omics expands the tree of life through the discovery of novel organisms, genes, and metabolic pathways. • Disadvantages of metagenome-assembled genomes are overcome by single-cell omics. • Functional analysis of single cells explores the heterogeneity of gene expression. • Technical challenges still limit this field, thus prompting new method developments.
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159
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Expanding the Diversity of Bacterioplankton Isolates and Modeling Isolation Efficacy with Large-Scale Dilution-to-Extinction Cultivation. Appl Environ Microbiol 2020; 86:AEM.00943-20. [PMID: 32561583 PMCID: PMC7440811 DOI: 10.1128/aem.00943-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 06/13/2020] [Indexed: 12/13/2022] Open
Abstract
Even before the coining of the term “great plate count anomaly” in the 1980s, scientists had noted the discrepancy between the number of microorganisms observed under the microscope and the number of colonies that grew on traditional agar media. New cultivation approaches have reduced this disparity, resulting in the isolation of some of the “most wanted” bacterial lineages. Nevertheless, the vast majority of microorganisms remain uncultured, hampering progress toward answering fundamental biological questions about many important microorganisms. Furthermore, few studies have evaluated the underlying factors influencing cultivation success, limiting our ability to improve cultivation efficacy. Our work details the use of dilution-to-extinction (DTE) cultivation to expand the phylogenetic and geographic diversity of available axenic cultures. We also provide a new model of the DTE approach that uses cultivation results and natural abundance information to predict taxon-specific viability and iteratively constrain DTE experimental design to improve cultivation success. Cultivated bacterioplankton representatives from diverse lineages and locations are essential for microbiology, but the large majority of taxa either remain uncultivated or lack isolates from diverse geographic locales. We paired large-scale dilution-to-extinction (DTE) cultivation with microbial community analysis and modeling to expand the phylogenetic and geographic diversity of cultivated bacterioplankton and to evaluate DTE cultivation success. Here, we report results from 17 DTE experiments totaling 7,820 individual incubations over 3 years, yielding 328 repeatably transferable isolates. Comparison of isolates to microbial community data for source waters indicated that we successfully isolated 5% of the observed bacterioplankton community throughout the study; 43% and 26% of our isolates matched operational taxonomic units and amplicon single-nucleotide variants, respectively, within the top 50 most abundant taxa. Isolates included those from previously uncultivated clades such as SAR11 LD12 and Actinobacteria acIV, as well as geographically novel members from other ecologically important groups like SAR11 subclade IIIa, SAR116, and others, providing isolates in eight putatively new genera and seven putatively new species. Using a newly developed DTE cultivation model, we evaluated taxon viability by comparing relative abundance with cultivation success. The model (i) revealed the minimum attempts required for successful isolation of taxa amenable to growth on our media and (ii) identified possible subpopulation viability variation in abundant taxa such as SAR11 that likely impacts cultivation success. By incorporating viability in experimental design, we can now statistically constrain the effort necessary for successful cultivation of specific taxa on a defined medium. IMPORTANCE Even before the coining of the term “great plate count anomaly” in the 1980s, scientists had noted the discrepancy between the number of microorganisms observed under the microscope and the number of colonies that grew on traditional agar media. New cultivation approaches have reduced this disparity, resulting in the isolation of some of the “most wanted” bacterial lineages. Nevertheless, the vast majority of microorganisms remain uncultured, hampering progress toward answering fundamental biological questions about many important microorganisms. Furthermore, few studies have evaluated the underlying factors influencing cultivation success, limiting our ability to improve cultivation efficacy. Our work details the use of dilution-to-extinction (DTE) cultivation to expand the phylogenetic and geographic diversity of available axenic cultures. We also provide a new model of the DTE approach that uses cultivation results and natural abundance information to predict taxon-specific viability and iteratively constrain DTE experimental design to improve cultivation success.
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160
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Burks DJ, Azad RK. Higher-order Markov models for metagenomic sequence classification. Bioinformatics 2020; 36:4130-4136. [PMID: 32516355 DOI: 10.1093/bioinformatics/btaa562] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Revised: 05/19/2020] [Accepted: 06/03/2020] [Indexed: 11/13/2022] Open
Abstract
MOTIVATION Alignment-free, stochastic models derived from k-mer distributions representing reference genome sequences have a rich history in the classification of DNA sequences. In particular, the variants of Markov models have previously been used extensively. Higher-order Markov models have been used with caution, perhaps sparingly, primarily because of the lack of enough training data and computational power. Advances in sequencing technology and computation have enabled exploitation of the predictive power of higher-order models. We, therefore, revisited higher-order Markov models and assessed their performance in classifying metagenomic sequences. RESULTS Comparative assessment of higher-order models (HOMs, 9th order or higher) with interpolated Markov model, interpolated context model and lower-order models (8th order or lower) was performed on metagenomic datasets constructed using sequenced prokaryotic genomes. Our results show that HOMs outperform other models in classifying metagenomic fragments as short as 100 nt at all taxonomic ranks, and at lower ranks when the fragment size was increased to 250 nt. HOMs were also found to be significantly more accurate than local alignment which is widely relied upon for taxonomic classification of metagenomic sequences. A novel software implementation written in C++ performs classification faster than the existing Markovian metagenomic classifiers and can therefore be used as a standalone classifier or in conjunction with existing taxonomic classifiers for more robust classification of metagenomic sequences. AVAILABILITY AND IMPLEMENTATION The software has been made available at https://github.com/djburks/SMM. CONTACT Rajeev.Azad@unt.edu. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
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Affiliation(s)
- David J Burks
- Department of Biological Sciences and BioDiscovery Institute
| | - Rajeev K Azad
- Department of Biological Sciences and BioDiscovery Institute.,Department of Mathematics, University of North Texas, Denton, TX 76203, USA
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161
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Avetisov SE, Abramova ND, Gogoleva NE, Gusev OA, Mitichkina TS, Novikov IA, Subbot AM, Shagimardanova EI. [Rational strategy for studying microbiome of the ocular surface of people using hard contact lenses by method of 16S rRNA gene metabarcoding]. Vestn Oftalmol 2020; 136:3-9. [PMID: 32504470 DOI: 10.17116/oftalma20201360313] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study is based on the hypothesis that high taxonomic diversity of bacteria detectable on the eye surface by molecular genetic methods is attributed to the high level of its contamination by skin microflora. Such contamination would make it problematic to identify the fractions of real ocular surface microbiome, which remains behind the one-percent cut-off threshold adopted in the metagenomic analysis. Hard contact lenses for long-wearing act as a physical filter preventing DNA contamination from random microorganisms, and at the same time providing adhesion to the living cells of bacteria and fungi. To confirm this assumption, a detailed analysis of references was carried out, supplemented by original laboratory research. MATERIAL AND METHODS The analysis included 16 hard contact lenses obtained from 11 patients with impaired refraction (myopia). Additionally, conjunctival mucosa scrapings were collected from 42 patients. Samples were cross-analyzed by 16S rRNA gene sequencing using 454 GS Junior (Ion Torrent) and Illumina MiSeq platforms. RESULTS Results obtained by the Illumina platform (analysis of the V3-V4 variable region of the 16S rRNA gene) showed better convergence with the data of culture tests reported in the literature. The major microorganism groups found were: Acinetobacter (39%), Gluconacetobacter (10.8%), Propionibacterium (9.3%), Corynebacterium (9.3%), Staphylococcus (7.2%), Streptococcus (7%), Pseudomonas (4.1%), Micrococcus (3.3%), Yersinia (3%), Chondromyces (2.4%), Serratia (2.3%), and Bacillus (2.1%). Analysis of the samples obtained directly from the mucosa revealed dominance of typical skin-associated microorganisms. CONCLUSION The present study proposes a contamination-reduction algorithm for microbiological testing of the ocular surface using hard contact lenses for prolonged wearing as a carrier for microbial DNA.
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Affiliation(s)
- S E Avetisov
- Research Institute of Eye Diseases, Moscow, Russia.,I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - N D Abramova
- Research Institute of Eye Diseases, Moscow, Russia
| | - N E Gogoleva
- Kazan Institute of Biochemistry and Biophysics - stand-alone branch of Kazan Scientific Center of RAS, Kazan, Russia.,Kazan Federal University (Volga Region), Institute of Fundamental Medicine and Biology, Kazan, Russia
| | - O A Gusev
- RIKEN-KFU Translational Genomics Unit, RIKEN Cluster for Science, Technology and Innovation Hub, Yokohama City, Japan
| | | | - I A Novikov
- Research Institute of Eye Diseases, Moscow, Russia
| | - A M Subbot
- Research Institute of Eye Diseases, Moscow, Russia
| | - E I Shagimardanova
- Kazan Federal University (Volga Region), Institute of Fundamental Medicine and Biology, Kazan, Russia
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162
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Bradley JA, Arndt S, Amend JP, Burwicz E, Dale AW, Egger M, LaRowe DE. Widespread energy limitation to life in global subseafloor sediments. SCIENCE ADVANCES 2020; 6:eaba0697. [PMID: 32821818 PMCID: PMC7406382 DOI: 10.1126/sciadv.aba0697] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Accepted: 06/23/2020] [Indexed: 05/05/2023]
Abstract
Microbial cells buried in subseafloor sediments comprise a substantial portion of Earth's biosphere and control global biogeochemical cycles; however, the rate at which they use energy (i.e., power) is virtually unknown. Here, we quantify organic matter degradation and calculate the power utilization of microbial cells throughout Earth's Quaternary-age subseafloor sediments. Aerobic respiration, sulfate reduction, and methanogenesis mediate 6.9, 64.5, and 28.6% of global subseafloor organic matter degradation, respectively. The total power utilization of the subseafloor sediment biosphere is 37.3 gigawatts, less than 0.1% of the power produced in the marine photic zone. Aerobic heterotrophs use the largest share of global power (54.5%) with a median power utilization of 2.23 × 10-18 watts per cell, while sulfate reducers and methanogens use 1.08 × 10-19 and 1.50 × 10-20 watts per cell, respectively. Most subseafloor cells subsist at energy fluxes lower than have previously been shown to support life, calling into question the power limit to life.
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Affiliation(s)
- J. A. Bradley
- School of Geography, Queen Mary University of London, London, UK
- Department of Geochemistry, GFZ, German Research Centre for Geosciences, Potsdam, Germany
| | - S. Arndt
- Department of Geosciences, Environment and Society, Université Libre de Bruxelles, Brussels, Belgium
| | - J. P. Amend
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - E. Burwicz
- GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Germany
| | - A. W. Dale
- GEOMAR, Helmholtz Centre for Ocean Research, Kiel, Germany
| | - M. Egger
- The Ocean Cleanup Foundation, Rotterdam, Netherlands
| | - D. E. LaRowe
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
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163
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Theuerl S, Klang J, Hülsemann B, Mächtig T, Hassa J. Microbiome Diversity and Community-Level Change Points within Manure-based small Biogas Plants. Microorganisms 2020; 8:microorganisms8081169. [PMID: 32752188 PMCID: PMC7464807 DOI: 10.3390/microorganisms8081169] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/21/2020] [Accepted: 07/30/2020] [Indexed: 12/21/2022] Open
Abstract
Efforts to integrate biogas plants into bioeconomy concepts will lead to an expansion of manure-based (small) biogas plants, while their operation is challenging due to critical characteristics of some types of livestock manure. For a better process understanding, in this study, three manure-based small biogas plants were investigated with emphasis on microbiome diversity. Due to varying digester types, feedstocks, and process conditions, 16S rRNA gene amplicon sequencing showed differences in the taxonomic composition. Dynamic variations of each investigated biogas plant microbiome over time were analyzed by terminal restriction fragment length polymorphism (TRFLP), whereby nonmetric multidimensional scaling (NMDS) revealed two well-running systems, one of them with a high share of chicken manure, and one unstable system. By using Threshold Indicator Taxa Analysis (TITAN), community-level change points at ammonium and ammonia concentrations of 2.25 g L-1 and 193 mg L-1 or volatile fatty acid concentrations of 0.75 g L-1were reliably identified which are lower than the commonly reported thresholds for critical process stages based on chemical parameters. Although a change in the microbiome structure does not necessarily indicate an upcoming critical process stage, the recorded community-level change points might be a first indication to carefully observe the process.
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Affiliation(s)
- Susanne Theuerl
- Department Bioengineering, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, Germany; (J.K.); or (J.H.)
- Correspondence: ; Tel.: +49-331-5699-900
| | - Johanna Klang
- Department Bioengineering, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, Germany; (J.K.); or (J.H.)
| | - Benedikt Hülsemann
- University of Hohenheim, The State Institute of Agricultural Engineering and Bioenergy, 70599 Stuttgart, Germany;
| | - Torsten Mächtig
- Kiel University, Institute of Agricultural Engineering, 24098 Kiel, Germany;
| | - Julia Hassa
- Department Bioengineering, Leibniz Institute for Agricultural Engineering and Bioeconomy, Max-Eyth-Allee 100, 14469 Potsdam, Germany; (J.K.); or (J.H.)
- Center for Biotechnology (CeBiTec), Genome Research of Industrial Microorganisms, Bielefeld University, 33615 Bielefeld, Germany
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164
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Rodriguez-R LM, Tsementzi D, Luo C, Konstantinidis KT. Iterative subtractive binning of freshwater chronoseries metagenomes identifies over 400 novel species and their ecologic preferences. Environ Microbiol 2020; 22:3394-3412. [PMID: 32495495 DOI: 10.1111/1462-2920.15112] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 04/26/2020] [Accepted: 05/31/2020] [Indexed: 01/22/2023]
Abstract
Recent advances in sequencing technology and bioinformatic pipelines have allowed unprecedented access to the genomes of yet-uncultivated microorganisms from diverse environments. However, the catalogue of freshwater genomes remains limited, and most genome recovery attempts in freshwater ecosystems have only targeted specific taxa. Here, we present a genome recovery pipeline incorporating iterative subtractive binning, and apply it to a time series of 100 metagenomic datasets from seven connected lakes and estuaries along the Chattahoochee River (Southeastern USA). Our set of metagenome-assembled genomes (MAGs) represents >400 yet-unnamed genomospecies, substantially increasing the number of high-quality MAGs from freshwater lakes. We propose names for two novel species: 'Candidatus Elulimicrobium humile' ('Ca. Elulimicrobiota', 'Patescibacteria') and 'Candidatus Aquidulcis frankliniae' ('Chloroflexi'). Collectively, our MAGs represented about half of the total microbial community at any sampling point. To evaluate the prevalence of these genomospecies in the chronoseries, we introduce methodologies to estimate relative abundance and habitat preference that control for uneven genome quality and sample representation. We demonstrate high degrees of habitat-specialization and endemicity for most genomospecies in the Chattahoochee lakes. Wider ecological ranges characterized smaller genomes with higher coding densities, indicating an overall advantage of smaller, more compact genomes for cosmopolitan distributions.
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Affiliation(s)
- Luis M Rodriguez-R
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Despina Tsementzi
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Chengwei Luo
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Dr NW, Atlanta, GA, 30332, USA
| | - Konstantinos T Konstantinidis
- School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Dr NW, Atlanta, GA, 30332, USA
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165
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Jarett JK, Džunková M, Schulz F, Roux S, Paez-Espino D, Eloe-Fadrosh E, Jungbluth SP, Ivanova N, Spear JR, Carr SA, Trivedi CB, Corsetti FA, Johnson HA, Becraft E, Kyrpides N, Stepanauskas R, Woyke T. Insights into the dynamics between viruses and their hosts in a hot spring microbial mat. ISME JOURNAL 2020; 14:2527-2541. [PMID: 32661357 PMCID: PMC7490370 DOI: 10.1038/s41396-020-0705-4] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 06/03/2020] [Accepted: 06/11/2020] [Indexed: 12/28/2022]
Abstract
Our current knowledge of host-virus interactions in biofilms is limited to computational predictions based on laboratory experiments with a small number of cultured bacteria. However, natural biofilms are diverse and chiefly composed of uncultured bacteria and archaea with no viral infection patterns and lifestyle predictions described to date. Herein, we predict the first DNA sequence-based host-virus interactions in a natural biofilm. Using single-cell genomics and metagenomics applied to a hot spring mat of the Cone Pool in Mono County, California, we provide insights into virus-host range, lifestyle and distribution across different mat layers. Thirty-four out of 130 single cells contained at least one viral contig (26%), which, together with the metagenome-assembled genomes, resulted in detection of 59 viruses linked to 34 host species. Analysis of single-cell amplification kinetics revealed a lack of active viral replication on the single-cell level. These findings were further supported by mapping metagenomic reads from different mat layers to the obtained host-virus pairs, which indicated a low copy number of viral genomes compared to their hosts. Lastly, the metagenomic data revealed high layer specificity of viruses, suggesting limited diffusion to other mat layers. Taken together, these observations indicate that in low mobility environments with high microbial abundance, lysogeny is the predominant viral lifestyle, in line with the previously proposed "Piggyback-the-Winner" theory.
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Affiliation(s)
- Jessica K Jarett
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,AnimalBiome, Oakland, CA, USA
| | - Mária Džunková
- Department of Energy Joint Genome Institute, Berkeley, CA, USA. .,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Frederik Schulz
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Simon Roux
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - David Paez-Espino
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Emiley Eloe-Fadrosh
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sean P Jungbluth
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Natalia Ivanova
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - John R Spear
- Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, USA
| | | | | | | | - Hope A Johnson
- California State University Fullerton, Fullerton, CA, USA
| | - Eric Becraft
- University of North Alabama, Florence, AL, USA.,Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Nikos Kyrpides
- Department of Energy Joint Genome Institute, Berkeley, CA, USA.,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Tanja Woyke
- Department of Energy Joint Genome Institute, Berkeley, CA, USA. .,Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,University of California, Merced, CA, USA.
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166
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Crits-Christoph A, Olm MR, Diamond S, Bouma-Gregson K, Banfield JF. Soil bacterial populations are shaped by recombination and gene-specific selection across a grassland meadow. THE ISME JOURNAL 2020; 14:1834-1846. [PMID: 32327732 PMCID: PMC7305173 DOI: 10.1038/s41396-020-0655-x] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 03/22/2020] [Accepted: 04/02/2020] [Indexed: 01/25/2023]
Abstract
Soil microbial diversity is often studied from the perspective of community composition, but less is known about genetic heterogeneity within species. The relative impacts of clonal interference, gene-specific selection, and recombination in many abundant but rarely cultivated soil microbes remain unknown. Here we track genome-wide population genetic variation for 19 highly abundant bacterial species sampled from across a grassland meadow. Genomic inferences about population structure are made using the millions of sequencing reads that are assembled de novo into consensus genomes from metagenomes, as each read pair describes a short genomic sequence from a cell in each population. Genomic nucleotide identity of assembled genomes was significantly associated with local geography for over half of the populations studied, and for a majority of populations within-sample nucleotide diversity could often be as high as meadow-wide nucleotide diversity. Genes involved in metabolite biosynthesis and extracellular transport were characterized by elevated nucleotide diversity in multiple species. Microbial populations displayed varying degrees of homologous recombination and recombinant variants were often detected at 7-36% of loci genome-wide. Within multiple populations we identified genes with unusually high spatial differentiation of alleles, fewer recombinant events, elevated ratios of nonsynonymous to synonymous variants, and lower nucleotide diversity, suggesting recent selective sweeps for gene variants. Taken together, these results indicate that recombination and gene-specific selection commonly shape genetic variation in several understudied soil bacterial lineages.
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Affiliation(s)
| | - Matthew R Olm
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Spencer Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Keith Bouma-Gregson
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Jillian F Banfield
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA.
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, USA.
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
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167
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Zhu D, Adebisi WA, Ahmad F, Sethupathy S, Danso B, Sun J. Recent Development of Extremophilic Bacteria and Their Application in Biorefinery. Front Bioeng Biotechnol 2020; 8:483. [PMID: 32596215 PMCID: PMC7303364 DOI: 10.3389/fbioe.2020.00483] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Accepted: 04/27/2020] [Indexed: 12/22/2022] Open
Abstract
The biorefining technology for biofuels and chemicals from lignocellulosic biomass has made great progress in the world. However, mobilization of laboratory research toward industrial setup needs to meet a series of criteria, including the selection of appropriate pretreatment technology, breakthrough in enzyme screening, pathway optimization, and production technology, etc. Extremophiles play an important role in biorefinery by providing novel metabolic pathways and catalytically stable/robust enzymes that are able to act as biocatalysts under harsh industrial conditions on their own. This review summarizes the potential application of thermophilic, psychrophilic alkaliphilic, acidophilic, and halophilic bacteria and extremozymes in the pretreatment, saccharification, fermentation, and lignin valorization process. Besides, the latest studies on the engineering bacteria of extremophiles using metabolic engineering and synthetic biology technologies for high-efficiency biofuel production are also introduced. Furthermore, this review explores the comprehensive application potential of extremophiles and extremozymes in biorefinery, which is partly due to their specificity and efficiency, and points out the necessity of accelerating the commercialization of extremozymes.
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Affiliation(s)
- Daochen Zhu
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Institute of Microbiology, Guangzhou, China
| | - Wasiu Adewale Adebisi
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Fiaz Ahmad
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Sivasamy Sethupathy
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Blessing Danso
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
| | - Jianzhong Sun
- Biofuels Institute, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, China
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168
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Coil DA, Neches RY, Lang JM, Jospin G, Brown WE, Cavalier D, Hampton-Marcell J, Gilbert JA, Eisen JA. Bacterial communities associated with cell phones and shoes. PeerJ 2020; 8:e9235. [PMID: 32551196 PMCID: PMC7292020 DOI: 10.7717/peerj.9235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 05/05/2020] [Indexed: 12/22/2022] Open
Abstract
Background Every human being carries with them a collection of microbes, a collection that is likely both unique to that person, but also dynamic as a result of significant flux with the surrounding environment. The interaction of the human microbiome (i.e., the microbes that are found directly in contact with a person in places such as the gut, mouth, and skin) and the microbiome of accessory objects (e.g., shoes, clothing, phones, jewelry) is of potential interest to both epidemiology and the developing field of microbial forensics. Therefore, the microbiome of personal accessories are of interest because they serve as both a microbial source and sink for an individual, they may provide information about the microbial exposure experienced by an individual, and they can be sampled non-invasively. Findings We report here a large-scale study of the microbiome found on cell phones and shoes. Cell phones serve as a potential source and sink for skin and oral microbiome, while shoes can act as sampling devices for microbial environmental experience. Using 16S rRNA gene sequencing, we characterized the microbiome of thousands of paired sets of cell phones and shoes from individuals at sporting events, museums, and other venues around the United States. Conclusions We place this data in the context of previous studies and demonstrate that the microbiome of phones and shoes are different. This difference is driven largely by the presence of “environmental” taxa (taxa from groups that tend to be found in places like soil) on shoes and human-associated taxa (taxa from groups that are abundant in the human microbiome) on phones. This large dataset also contains many novel taxa, highlighting the fact that much of microbial diversity remains uncharacterized, even on commonplace objects.
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Affiliation(s)
- David A Coil
- Genome Center, University of California, Davis, CA, United States of America
| | - Russell Y Neches
- Genome Center, University of California, Davis, CA, United States of America
| | - Jenna M Lang
- Genome Center, University of California, Davis, CA, United States of America
| | - Guillaume Jospin
- Genome Center, University of California, Davis, CA, United States of America
| | - Wendy E Brown
- Department of Biomedical Engineering, University of California, Irvine, CA, United States of America.,Science Cheerleaders, Inc., Philadelphia, PA, United States of America
| | - Darlene Cavalier
- Science Cheerleaders, Inc., Philadelphia, PA, United States of America.,SciStarter.org, Philadelphia, PA, United States of America
| | - Jarrad Hampton-Marcell
- Argonne National Laboratory, University of Chicago, Lemont, IL, United States of America
| | - Jack A Gilbert
- Department of Pediatrics and Scripps Institution of Oceanography, UC San Diego School of Medicine, San Diego, CA, United States of America
| | - Jonathan A Eisen
- Genome Center, Department of Evolution and Ecology, Department of Medical Microbiology and Immunology, University of California, Davis, Davis, CA, United States of America
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169
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Murray AE, Freudenstein J, Gribaldo S, Hatzenpichler R, Hugenholtz P, Kämpfer P, Konstantinidis KT, Lane CE, Papke RT, Parks DH, Rossello-Mora R, Stott MB, Sutcliffe IC, Thrash JC, Venter SN, Whitman WB, Acinas SG, Amann RI, Anantharaman K, Armengaud J, Baker BJ, Barco RA, Bode HB, Boyd ES, Brady CL, Carini P, Chain PSG, Colman DR, DeAngelis KM, de Los Rios MA, Estrada-de Los Santos P, Dunlap CA, Eisen JA, Emerson D, Ettema TJG, Eveillard D, Girguis PR, Hentschel U, Hollibaugh JT, Hug LA, Inskeep WP, Ivanova EP, Klenk HP, Li WJ, Lloyd KG, Löffler FE, Makhalanyane TP, Moser DP, Nunoura T, Palmer M, Parro V, Pedrós-Alió C, Probst AJ, Smits THM, Steen AD, Steenkamp ET, Spang A, Stewart FJ, Tiedje JM, Vandamme P, Wagner M, Wang FP, Yarza P, Hedlund BP, Reysenbach AL. Roadmap for naming uncultivated Archaea and Bacteria. Nat Microbiol 2020; 5:987-994. [PMID: 32514073 PMCID: PMC7381421 DOI: 10.1038/s41564-020-0733-x] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 05/01/2020] [Indexed: 11/09/2022]
Abstract
The assembly of single-amplified genomes (SAGs) and metagenome-assembled genomes (MAGs) has led to a surge in genome-based discoveries of members affiliated with Archaea and Bacteria, bringing with it a need to develop guidelines for nomenclature of uncultivated microorganisms. The International Code of Nomenclature of Prokaryotes (ICNP) only recognizes cultures as 'type material', thereby preventing the naming of uncultivated organisms. In this Consensus Statement, we propose two potential paths to solve this nomenclatural conundrum. One option is the adoption of previously proposed modifications to the ICNP to recognize DNA sequences as acceptable type material; the other option creates a nomenclatural code for uncultivated Archaea and Bacteria that could eventually be merged with the ICNP in the future. Regardless of the path taken, we believe that action is needed now within the scientific community to develop consistent rules for nomenclature of uncultivated taxa in order to provide clarity and stability, and to effectively communicate microbial diversity.
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Affiliation(s)
- Alison E Murray
- Division of Earth and Ecosystem Sciences, Desert Research Institute, Reno, NV, USA.
| | - John Freudenstein
- Department of Evolution, Ecology and Organismal Biology, The Ohio State University, Columbus, OH, USA
| | - Simonetta Gribaldo
- Evolutionary Biology of the Microbial Cell, Department of Microbiology, Institut Pasteur, Paris, France
| | - Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Philip Hugenholtz
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Peter Kämpfer
- Department of Applied Microbiology, Justus-Liebig-Universität, Giessen, Germany
| | | | - Christopher E Lane
- Department of Biological Sciences, University of Rhode Island, Kingston, RI, USA
| | - R Thane Papke
- Department of Molecular and Cellular Biology, University of Connecticut, Storrs, CT, USA
| | - Donovan H Parks
- Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | - Ramon Rossello-Mora
- Mediterranean Institute for Advanced Studies, CSIC-UIB, Illes Balears, Spain
| | - Matthew B Stott
- School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
| | - Iain C Sutcliffe
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - J Cameron Thrash
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
| | - Stephanus N Venter
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | | | - Silvia G Acinas
- Department of Marine Biology and Oceanography, Institut de Ciènces del Mar, CSIC, Barcelona, Spain
| | - Rudolf I Amann
- Max Planck Institute for Marine Microbiology, Bremen, Germany
| | | | - Jean Armengaud
- CEA Technological Innovations for Detection and Diagnosis Laboratory, CEA Pharmacology and Immunoanalysis Unit (SPI), Bagnols-sur-Cèze, France
| | - Brett J Baker
- Department of Marine Science, Marine Science Institute, University of Texas at Austin, Port Aransas, TX, USA
| | - Roman A Barco
- Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
| | - Helge B Bode
- Molecular Biotechnology, Department of Biosciences and Buchmann Institute for Molecular Life Sciences (BMLS), Goethe University Frankfurt, Frankfurt am Main, Germany.,Senckenberg Society for Nature Research, Frankfurt am Main, Germany
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | | | - Paul Carini
- Department of Environmental Science, University of Arizona, Tuscon, AZ, USA
| | - Patrick S G Chain
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Daniel R Colman
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | | | | | | | - Christopher A Dunlap
- National Center for Agricultural Utilization Research, Crop Bioprotection Research Unit, Peoria, IL, USA
| | - Jonathan A Eisen
- Department of Evolution and Ecology, Department of Medical Microbiology and Immunology, University of California, Davis, CA, USA
| | - David Emerson
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME, USA
| | - Thijs J G Ettema
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, the Netherlands
| | | | - Peter R Girguis
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Ute Hentschel
- GEOMAR-Helmholtz Centre for Ocean Research, RD3-Marine Ecology, RU-Marine Microbiology, Kiel, Germany
| | | | - Laura A Hug
- Department of Biology, University of Waterloo, Waterloo, Canada
| | - William P Inskeep
- Department of Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - Elena P Ivanova
- School of Science, RMIT University, Melbourne, Victoria, Australia
| | - Hans-Peter Klenk
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Wen-Jun Li
- School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Karen G Lloyd
- Department of Microbiology, University of Tennessee, Knoxville, TN, USA
| | - Frank E Löffler
- Departments of Microbiology and Civil & Environmental Engineering, Center for Environmental Biotechnology, University of Tennessee, Knoxville, TN, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Thulani P Makhalanyane
- Centre for Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Duane P Moser
- Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, NV, USA
| | - Takuro Nunoura
- Research Center for Bioscience and Nanoscience (CeBN), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Marike Palmer
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA
| | | | | | - Alexander J Probst
- Department of Chemistry, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Theo H M Smits
- Environmental Genomics and Systems Biology Research Group, Institute for Environment and Natural Resources, Zürich University for Applied Sciences (ZHAW), Wädenswil, Switzerland
| | - Andrew D Steen
- Departments of Microbiology and Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
| | - Anja Spang
- Department for Marine Microbiology and Biogeochemistry, Royal Netherlands Institute for Sea Research, Den Burg, the Netherlands.,Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Frank J Stewart
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - James M Tiedje
- Center for Microbial Ecology, Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, USA
| | - Peter Vandamme
- Department of Biochemistry and Microbiology, Ghent University, Gent, Belgium
| | - Michael Wagner
- Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
| | - Feng-Ping Wang
- International Center for Deep Life Investigation, School of Oceanography and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | | | - Brian P Hedlund
- School of Life Sciences, University of Nevada, Las Vegas, NV, USA.
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170
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Adam N, Schlicht S, Han Y, Bechelany M, Bachmann J, Perner M. Metagenomics Meets Electrochemistry: Utilizing the Huge Catalytic Potential From the Uncultured Microbial Majority for Energy-Storage. Front Bioeng Biotechnol 2020; 8:567. [PMID: 32582677 PMCID: PMC7287016 DOI: 10.3389/fbioe.2020.00567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 05/11/2020] [Indexed: 11/25/2022] Open
Abstract
Hydrogen can in the future serve as an advantageous carrier of renewable energy if its production via water electrolysis and utilization in fuel cells are realized with high energy efficiency and non-precious electrocatalysts. In an unprecedented novel combination of structured electrodes with hydrogen converting enzymes from the uncultured and thus largely inaccessible microbial majority (>99%) we address this challenge. The geometrically defined electrodes with large specific surface area allow for low overpotentials and high energy efficiencies to be achieved. Enzymatic hydrogen evolution electrocatalysts are used as alternatives to noble metals. The enzymes are harnessed from the environmental microbial DNA (metagenomes) of hydrothermal vents exhibiting dynamic hydrogen and oxygen concentrations and are recovered via a recently developed novel activity-based screening tool. The screen enables us to target currently unrecognized hydrogenase enzymes from metagenomes via direct expression in a surrogate host microorganism. This circumvents the need for cultivation of the source organisms, the primary bottleneck when harnessing enzymes from microbes. One hydrogen converting metagenome-derived enzyme exhibited high activity and unusually high stability when dispersed on a TiO2-coated polyacrylonitrile fiber electrode. Our results highlight the tremendous potential of enzymes derived from uncultured microorganisms for applications in energy conversion and storage technologies.
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Affiliation(s)
- Nicole Adam
- Molecular Biology of Microbial Consortia, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Stefanie Schlicht
- Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nürnberg, Interdisciplinary Center for Nanostructured Films (IZNF), Erlangen, Germany
| | - Yuchen Han
- Molecular Biology of Microbial Consortia, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
| | - Mikhael Bechelany
- Institut Européen des Membranes, IEM – UMR 5635, ENSCM, CNRS, Univ Montpellier, Montpellier, France
| | - Julien Bachmann
- Department of Chemistry and Pharmacy, Friedrich-Alexander University of Erlangen-Nürnberg, Interdisciplinary Center for Nanostructured Films (IZNF), Erlangen, Germany
- Institute of Chemistry, Saint-Petersburg State University, Universitetskiy Prospekt, St. Petersburg, Russia
| | - Mirjam Perner
- Molecular Biology of Microbial Consortia, Biocenter Klein Flottbek, University of Hamburg, Hamburg, Germany
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171
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Carrier B, Beaty D, Meyer M, Blank J, Chou L, DasSarma S, Des Marais D, Eigenbrode J, Grefenstette N, Lanza N, Schuerger A, Schwendner P, Smith H, Stoker C, Tarnas J, Webster K, Bakermans C, Baxter B, Bell M, Benner S, Bolivar Torres H, Boston P, Bruner R, Clark B, DasSarma P, Engelhart A, Gallegos Z, Garvin Z, Gasda P, Green J, Harris R, Hoffman M, Kieft T, Koeppel A, Lee P, Li X, Lynch K, Mackelprang R, Mahaffy P, Matthies L, Nellessen M, Newsom H, Northup D, O'Connor B, Perl S, Quinn R, Rowe L, Sauterey B, Schneegurt M, Schulze-Makuch D, Scuderi L, Spilde M, Stamenković V, Torres Celis J, Viola D, Wade B, Walker C, Wiens R, Williams A, Williams J, Xu J. Mars Extant Life: What's Next? Conference Report. ASTROBIOLOGY 2020; 20:785-814. [PMID: 32466662 PMCID: PMC7307687 DOI: 10.1089/ast.2020.2237] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/24/2020] [Indexed: 05/19/2023]
Abstract
On November 5-8, 2019, the "Mars Extant Life: What's Next?" conference was convened in Carlsbad, New Mexico. The conference gathered a community of actively publishing experts in disciplines related to habitability and astrobiology. Primary conclusions are as follows: A significant subset of conference attendees concluded that there is a realistic possibility that Mars hosts indigenous microbial life. A powerful theme that permeated the conference is that the key to the search for martian extant life lies in identifying and exploring refugia ("oases"), where conditions are either permanently or episodically significantly more hospitable than average. Based on our existing knowledge of Mars, conference participants highlighted four potential martian refugium (not listed in priority order): Caves, Deep Subsurface, Ices, and Salts. The conference group did not attempt to reach a consensus prioritization of these candidate environments, but instead felt that a defensible prioritization would require a future competitive process. Within the context of these candidate environments, we identified a variety of geological search strategies that could narrow the search space. Additionally, we summarized a number of measurement techniques that could be used to detect evidence of extant life (if present). Again, it was not within the scope of the conference to prioritize these measurement techniques-that is best left for the competitive process. We specifically note that the number and sensitivity of detection methods that could be implemented if samples were returned to Earth greatly exceed the methodologies that could be used at Mars. Finally, important lessons to guide extant life search processes can be derived both from experiments carried out in terrestrial laboratories and analog field sites and from theoretical modeling.
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Affiliation(s)
- B.L. Carrier
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - D.W. Beaty
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - J.G. Blank
- NASA Ames Research Center, Moffett Field, California, USA
- Blue Marble Space Institute of Science, Seattle, Washington, USA
| | - L. Chou
- Georgetown University, Washington, DC, USA
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - S. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | | | | | - N.L. Lanza
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - A.C. Schuerger
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - P. Schwendner
- University of Florida/Space Life Sciences Laboratory, Kennedy Space Center, Florida, USA
| | - H.D. Smith
- NASA Ames Research Center, Moffett Field, California, USA
| | - C.R. Stoker
- NASA Ames Research Center, Moffett Field, California, USA
| | - J.D. Tarnas
- Brown University, Providence, Rhode Island, USA
| | - K.D. Webster
- Planetary Science Institute, Tucson, Arizona, USA
| | - C. Bakermans
- Pennsylvania State University, Altoona, Pennsylvania, USA
| | - B.K. Baxter
- Westminster College, Salt Lake City, Utah, USA
| | - M.S. Bell
- NASA Johnson Space Center, Houston, Texas, USA
| | - S.A. Benner
- Foundation for Applied Molecular Evolution, Alachua, Florida, USA
| | - H.H. Bolivar Torres
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - P.J. Boston
- NASA Astrobiology Institute, NASA Ames Research Center, Moffett Field, California, USA
| | - R. Bruner
- Denver Museum of Nature and Science, Denver, Colorado, USA
| | - B.C. Clark
- Space Science Institute, Littleton, Colorado, USA
| | - P. DasSarma
- Department of Microbiology and Immunology, Institute of Marine and Environmental Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | | | - Z.E. Gallegos
- University of New Mexico, Albuquerque, New Mexico, USA
| | - Z.K. Garvin
- Princeton University, Princeton, New Jersey, USA
| | - P.J. Gasda
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | - J.H. Green
- Texas Tech University, Lubbock, Texas, USA
| | - R.L. Harris
- Princeton University, Princeton, New Jersey, USA
| | - M.E. Hoffman
- University of New Mexico, Albuquerque, New Mexico, USA
| | - T. Kieft
- New Mexico Institute of Mining and Technology, Socorro, New Mexico, USA
| | | | - P.A. Lee
- College of Charleston, Charleston, South Carolina, USA
| | - X. Li
- University of Maryland Baltimore County, Baltimore, Maryland, USA
| | - K.L. Lynch
- Lunar and Planetary Institute/USRA, Houston, Texas, USA
| | - R. Mackelprang
- California State University Northridge, Northridge, California, USA
| | - P.R. Mahaffy
- NASA Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - L.H. Matthies
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | | | - H.E. Newsom
- University of New Mexico, Albuquerque, New Mexico, USA
| | - D.E. Northup
- University of New Mexico, Albuquerque, New Mexico, USA
| | | | - S.M. Perl
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - R.C. Quinn
- NASA Ames Research Center, Moffett Field, California, USA
| | - L.A. Rowe
- Valparaiso University, Valparaiso, Indiana, USA
| | | | | | | | - L.A. Scuderi
- University of New Mexico, Albuquerque, New Mexico, USA
| | - M.N. Spilde
- University of New Mexico, Albuquerque, New Mexico, USA
| | - V. Stamenković
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA
| | - J.A. Torres Celis
- Universidad Nacional Autonoma de Mexico, Coyoacan, Distrito Federal Mexico, Mexico
| | - D. Viola
- NASA Ames Research Center, Moffett Field, California, USA
| | - B.D. Wade
- Michigan State University, East Lansing, Michigan, USA
| | - C.J. Walker
- Delaware State University, Dover, Delaware, USA
| | - R.C. Wiens
- Los Alamos National Laboratory, Los Alamos, New Mexico, USA
| | | | - J.M. Williams
- University of New Mexico, Albuquerque, New Mexico, USA
| | - J. Xu
- University of Texas, El Paso, Texas, USA
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172
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Host Species Determines the Composition of the Prokaryotic Microbiota in Phlebotomus Sandflies. Pathogens 2020; 9:pathogens9060428. [PMID: 32485988 PMCID: PMC7350354 DOI: 10.3390/pathogens9060428] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 05/27/2020] [Accepted: 05/28/2020] [Indexed: 12/28/2022] Open
Abstract
Phlebotomine sandflies are vectors of the humans' and mammals' parasite Leishmania spp. Although the role of gut microbiome in the biological cycle of insects is acknowledged, we still know little about the factors modulating the composition of the gut microbiota of sandflies. We tested whether host species impose a strong structural effect on the gut microbiota of Phlebotomus spp. Sandflies were collected from the island of Leros, Greece, and classified to P. papatasi, P. neglectus, P. tobbi, and P. similis, all being negative to Leishmania spp. The prokaryotic gut microbiota was determined via 16S rRNA gene amplicon sequencing. Phlebotomus species supported distinct microbial communities (p < 0.001). P. papatasi microbiota was the most distinct over-dominated by three Spiroplasma, Wolbachia and Paenibacillus operational taxonomic units (OTUs), while another Wolbachia OTU prevailed in P. neglectus. Conversely, the microbiota of P. tobbi and P. similis was composed of several less dominant OTUs. Archaea showed low presence with the dominant OTUs belonging to methanogenic Euryarcheota, ammonia-oxidizing Thaumarcheota, and Nanoarchaeota. We provide first insights into the composition of the bacterial and archaeal community of Phlebotomus sandflies and showed that, in the absence of Leishmania, host genotype is the major modulator of Phlebotomus sandfly gut microbiota.
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173
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Juvigny-Khenafou NPD, Zhang Y, Piggott JJ, Atkinson D, Matthaei CD, Van Bael SA, Wu N. Anthropogenic stressors affect fungal more than bacterial communities in decaying leaf litter: A stream mesocosm experiment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 716:135053. [PMID: 31859062 DOI: 10.1016/j.scitotenv.2019.135053] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Despite the progress made in environmental microbiology techniques and knowledge, the succession and functional changes of the microbial community under multiple stressors are still poorly understood. This is a substantial knowledge gap as microbial communities regulate the biogeochemistry of stream ecosystems. Our study assessed the structural and temporal changes in stream fungal and bacterial communities associated with decomposing leaf litter under a multiple-stressor scenario. We conducted a fully crossed 4-factor experiment in 64 flow-through mesocosms fed by a pristine montane stream (21 days of colonisation, 21 days of manipulations) and investigated the effects of nutrient enrichment, flow velocity reduction and sedimentation after 2 and 3 weeks of stressor exposure. We used high-throughput sequencing and metabarcoding techniques (16S and 18S rRNA genes) to identify changes in microbial community composition. Our results indicate that (1) shifts in relative abundances of the pre-existing terrestrial microbial community, rather than changes in community identity, drove the observed responses to stressors; (2) changes in relative abundances within the microbial community paralleled decomposition rate patterns with time; (3) both fungal and bacterial communities had a certain resistance to stressors, as indicated by relatively minor changes in alpha diversity or multivariate community structure; (4) overall, stressor interactions were more common than stressor main effects when affecting microbial diversity metrics or abundant individual genera; and (5) stressor effects on microbes often changed from 2 weeks to 3 weeks of stressor exposure, with several response patterns being reversed. Our study suggests that future research should focus more on understanding the temporal dynamics of fungal and bacterial communities and how they relate to ecosystem processes to advance our understanding of the mechanisms associated with multiple-stressor interactions.
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Affiliation(s)
- Noël P D Juvigny-Khenafou
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK; Department of Health and Environmental Science, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
| | - Yixin Zhang
- Department of Landscape Architecture, Gold Mantis School of Architecture, Soochow University, Suzhou, China.
| | - Jeremy J Piggott
- Trinity Centre for the Environment & Department of Zoology, School of Natural Sciences, Trinity College Dublin, The University of Dublin, College Green, Dublin 2, Ireland
| | - David Atkinson
- Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK
| | - Christoph D Matthaei
- Department of Zoology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Sunshine A Van Bael
- Department of Ecology and Evolutionary Biology, Tulane University, 6823 St. Charles Avenue, Boggs 400, New Orleans, LA 70118, USA
| | - Naicheng Wu
- Department of Health and Environmental Science, Xi'an Jiaotong-Liverpool University, Suzhou, Jiangsu 215123, China
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174
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Müller V, Nyblom M, Johnning A, Wrande M, Dvirnas A, KK S, Giske CG, Ambjörnsson T, Sandegren L, Kristiansson E, Westerlund F. Cultivation-Free Typing of Bacteria Using Optical DNA Mapping. ACS Infect Dis 2020; 6:1076-1084. [PMID: 32294378 PMCID: PMC7304876 DOI: 10.1021/acsinfecdis.9b00464] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Indexed: 01/06/2023]
Abstract
A variety of pathogenic bacteria can infect humans, and rapid species identification is crucial for the correct treatment. However, the identification process can often be time-consuming and depend on the cultivation of the bacterial pathogen(s). Here, we present a stand-alone, enzyme-free, optical DNA mapping assay capable of species identification by matching the intensity profiles of large DNA molecules to a database of fully assembled bacterial genomes (>10 000). The assay includes a new data analysis strategy as well as a general DNA extraction protocol for both Gram-negative and Gram-positive bacteria. We demonstrate that the assay is capable of identifying bacteria directly from uncultured clinical urine samples, as well as in mixtures, with the potential to be discriminative even at the subspecies level. We foresee that the assay has applications both within research laboratories and in clinical settings, where the time-consuming step of cultivation can be minimized or even completely avoided.
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Affiliation(s)
- Vilhelm Müller
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - My Nyblom
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Anna Johnning
- Department of Mathematical
Sciences, Chalmers University of Technology
and the University of Gothenburg, 412 96 Gothenburg, Sweden
- Systems and Data Analysis, Fraunhofer-Chalmers
Centre, Chalmers Science
Park, 412 88 Gothenburg, Sweden
- Centre for Antibiotic Resistance Research,
CARe, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden
| | - Marie Wrande
- Department of Medical
Biochemistry and Microbiology, Uppsala University, Husargatan 3, Box
582, 751 23 Uppsala, Sweden
| | - Albertas Dvirnas
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 223 62 Lund, Sweden
| | - Sriram KK
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
| | - Christian G. Giske
- Department of Laboratory Medicine, Karolinska
Institutet, Alfred Nobels
Allé 8, 141 86 Stockholm, Sweden
- Department of Clinical
Microbiology, Karolinska University Hospital, 171 76 Stockholm, Sweden
| | - Tobias Ambjörnsson
- Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, 223 62 Lund, Sweden
| | - Linus Sandegren
- Department of Medical
Biochemistry and Microbiology, Uppsala University, Husargatan 3, Box
582, 751 23 Uppsala, Sweden
| | - Erik Kristiansson
- Department of Mathematical
Sciences, Chalmers University of Technology
and the University of Gothenburg, 412 96 Gothenburg, Sweden
- Centre for Antibiotic Resistance Research,
CARe, University of Gothenburg, Box 440, 405 30 Gothenburg, Sweden
| | - Fredrik Westerlund
- Department of Biology
and Biological Engineering, Chalmers University
of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
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175
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Pishchany G. Applying microbial ecology to antimicrobial discovery. Curr Opin Microbiol 2020; 57:7-12. [PMID: 32339893 DOI: 10.1016/j.mib.2020.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/24/2020] [Accepted: 03/30/2020] [Indexed: 01/27/2023]
Abstract
Introduction of antibiotics into clinical use has contributed to some of the greatest improvements to public health in the 20th century. Most antibiotics are based on antimicrobials that were isolated from environmental microorganisms over 50 years ago, but emerging resistance requires discovery of new molecules and development of these molecules into therapeutics. Bioinformatic analyses of microbial genomes indicate that many more microbial bioactive molecules remain undiscovered. Understanding when, where, and why these molecules are produced informs efforts to tap into the hidden unexplored chemical diversity. Expanding the search to undersampled ecological niches and improving culturing techniques will ensure discovery of new antibiotics.
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Affiliation(s)
- Gleb Pishchany
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA.
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176
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Coming-of-Age Characterization of Soil Viruses: A User’s Guide to Virus Isolation, Detection within Metagenomes, and Viromics. SOIL SYSTEMS 2020. [DOI: 10.3390/soilsystems4020023] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The study of soil viruses, though not new, has languished relative to the study of marine viruses. This is particularly due to challenges associated with separating virions from harboring soils. Generally, three approaches to analyzing soil viruses have been employed: (1) Isolation, to characterize virus genotypes and phenotypes, the primary method used prior to the start of the 21st century. (2) Metagenomics, which has revealed a vast diversity of viruses while also allowing insights into viral community ecology, although with limitations due to DNA from cellular organisms obscuring viral DNA. (3) Viromics (targeted metagenomics of virus-like-particles), which has provided a more focused development of ‘virus-sequence-to-ecology’ pipelines, a result of separation of presumptive virions from cellular organisms prior to DNA extraction. This separation permits greater sequencing emphasis on virus DNA and thereby more targeted molecular and ecological characterization of viruses. Employing viromics to characterize soil systems presents new challenges, however. Ones that only recently are being addressed. Here we provide a guide to implementing these three approaches to studying environmental viruses, highlighting benefits, difficulties, and potential contamination, all toward fostering greater focus on viruses in the study of soil ecology.
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177
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Lewis K. The Science of Antibiotic Discovery. Cell 2020; 181:29-45. [DOI: 10.1016/j.cell.2020.02.056] [Citation(s) in RCA: 209] [Impact Index Per Article: 52.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/18/2020] [Accepted: 02/26/2020] [Indexed: 02/07/2023]
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178
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Sun Y, Liu Y, Pan J, Wang F, Li M. Perspectives on Cultivation Strategies of Archaea. MICROBIAL ECOLOGY 2020; 79:770-784. [PMID: 31432245 DOI: 10.1007/s00248-019-01422-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 08/01/2019] [Indexed: 06/10/2023]
Abstract
Archaea have been recognized as a major domain of life since the 1970s and occupy a key position in the tree of life. Recent advances in culture-independent approaches have greatly accelerated the research son Archaea. However, many hypotheses concerning the diversity, physiology, and evolution of archaea are waiting to be confirmed by culture-base experiments. Consequently, archaeal isolates are in great demand. On the other hand, traditional approaches of archaeal cultivation are rarely successful and require urgent improvement. Here, we review the current practices and applicable microbial cultivation techniques, to inform on potential strategies that could improve archaeal cultivation in the future. We first summarize the current knowledge on archaeal diversity, with an emphasis on cultivated and uncultivated lineages pertinent to future research. Possible causes for the low success rate of the current cultivation practices are then discussed to propose future improvements. Finally, innovative insights for archaeal cultivation are described, including (1) medium refinement for selective cultivation based on the genetic and transcriptional information; (2) consideration of the up-to-date archaeal culturing skills; and (3) application of multiple cultivation techniques, such as co-culture, direct interspecies electron transfer (DIET), single-cell isolation, high-throughput culturing (HTC), and simulation of the natural habitat. Improved cultivation efforts should allow successful isolation of as yet uncultured archaea, contributing to the much-needed physiological investigation of archaea.
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Affiliation(s)
- Yihua Sun
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
| | - Yang Liu
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
| | - Jie Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, People's Republic of China
- State Key Laboratory of Ocean Engineering, Shanghai Jiao Tong University, Shanghai, People's Republic of China
| | - Meng Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, Guangdong, People's Republic of China.
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179
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Cai M, Liu Y, Yin X, Zhou Z, Friedrich MW, Richter-Heitmann T, Nimzyk R, Kulkarni A, Wang X, Li W, Pan J, Yang Y, Gu JD, Li M. Diverse Asgard archaea including the novel phylum Gerdarchaeota participate in organic matter degradation. SCIENCE CHINA-LIFE SCIENCES 2020; 63:886-897. [PMID: 32201928 DOI: 10.1007/s11427-020-1679-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 03/12/2020] [Indexed: 01/14/2023]
Abstract
Asgard is an archaeal superphylum that might hold the key to understand the origin of eukaryotes, but its diversity and ecological roles remain poorly understood. Here, we reconstructed 15 metagenomic-assembled genomes from coastal sediments covering most known Asgard archaea and a novel group, which is proposed as a new Asgard phylum named as the "Gerdarchaeota". Genomic analyses predict that Gerdarchaeota are facultative anaerobes in utilizing both organic and inorganic carbon. Unlike their closest relatives Heimdallarchaeota, Gerdarchaeota have genes encoding for cellulase and enzymes involved in the tetrahydromethanopterin-based Wood-Ljungdahl pathway. Transcriptomics showed that most of our identified Asgard archaea are capable of degrading organic matter, including peptides, amino acids and fatty acids, occupying ecological niches in different depths of layers of the sediments. Overall, this study broadens the diversity of the mysterious Asgard archaea and provides evidence for their ecological roles in coastal sediments.
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Affiliation(s)
- Mingwei Cai
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Yang Liu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Xiuran Yin
- Microbial Ecophysiology Group, Faculty of Biology/Chemistry, University of Bremen, Bremen, D-28359, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, D-28359, Germany
| | - Zhichao Zhou
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong, 999077, China
| | - Michael W Friedrich
- Microbial Ecophysiology Group, Faculty of Biology/Chemistry, University of Bremen, Bremen, D-28359, Germany
- MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, D-28359, Germany
| | - Tim Richter-Heitmann
- Microbial Ecophysiology Group, Faculty of Biology/Chemistry, University of Bremen, Bremen, D-28359, Germany
| | - Rolf Nimzyk
- Department of Microbe-Plant Interactions, Faculty of Biology/Chemistry, University of Bremen, Bremen, D-28359, Germany
| | - Ajinkya Kulkarni
- Microbial Ecophysiology Group, Faculty of Biology/Chemistry, University of Bremen, Bremen, D-28359, Germany
| | - Xiaowen Wang
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
- Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Wenjin Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Jie Pan
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Yuchun Yang
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong, 999077, China
| | - Ji-Dong Gu
- Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Hong Kong, 999077, China
| | - Meng Li
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China.
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180
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Wang Y, Hu Y, Gao GF. Combining metagenomics and metatranscriptomics to study human, animal and environmental resistomes. MEDICINE IN MICROECOLOGY 2020. [DOI: 10.1016/j.medmic.2020.100014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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181
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Pascoal F, Magalhães C, Costa R. The Link Between the Ecology of the Prokaryotic Rare Biosphere and Its Biotechnological Potential. Front Microbiol 2020; 11:231. [PMID: 32140148 PMCID: PMC7042395 DOI: 10.3389/fmicb.2020.00231] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 01/31/2020] [Indexed: 12/15/2022] Open
Abstract
Current research on the prokaryotic low abundance taxa, the prokaryotic rare biosphere, is growing, leading to a greater understanding of the mechanisms underlying organismal rarity and its relevance in ecology. From this emerging knowledge it is possible to envision innovative approaches in biotechnology applicable to several sectors. Bioremediation and bioprospecting are two of the most promising areas where such approaches could find feasible implementation, involving possible new solutions to the decontamination of polluted sites and to the discovery of novel gene variants and pathways based on the attributes of rare microbial communities. Bioremediation can be improved through the realization that diverse rare species can grow abundant and degrade different pollutants or possibly transfer useful genes. Further, most of the prokaryotic diversity found in virtually all environments belongs in the rare biosphere and remains uncultivatable, suggesting great bioprospecting potential within this vast and understudied genetic pool. This Mini Review argues that knowledge of the ecophysiology of rare prokaryotes can aid the development of future, efficient biotechnology-based processes, products and services. However, this promise may only be fulfilled through improvements in (and optimal blending of) advanced microbial culturing and physiology, metagenomics, genome annotation and editing, and synthetic biology, to name a few areas of relevance. In the future, it will be important to understand how activity profiles relate with abundance, as some rare taxa can remain rare and increase activity, whereas other taxa can grow abundant. The metabolic mechanisms behind those patterns can be useful in designing biotechnological processes.
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Affiliation(s)
- Francisco Pascoal
- Department of Bioengineering, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal.,Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal
| | - Catarina Magalhães
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR), University of Porto, Porto, Portugal.,Faculty of Sciences, University of Porto, Porto, Portugal.,School of Science & Engineering, University of Waikato, Hamilton, New Zealand.,Ocean Frontier Institute, Dalhousie University, Halitax, NS, Canada
| | - Rodrigo Costa
- Department of Bioengineering, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal.,Centre of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal.,U.S. Department of Energy Joint Genome Institute, Berkeley, CA, United States.,Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
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182
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Rego A, Sousa AGG, Santos JP, Pascoal F, Canário J, Leão PN, Magalhães C. Diversity of Bacterial Biosynthetic Genes in Maritime Antarctica. Microorganisms 2020; 8:microorganisms8020279. [PMID: 32085500 PMCID: PMC7074882 DOI: 10.3390/microorganisms8020279] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 02/14/2020] [Accepted: 02/14/2020] [Indexed: 02/06/2023] Open
Abstract
Bacterial natural products (NPs) are still a major source of new drug leads. Polyketides (PKs) and non-ribosomal peptides (NRP) are two pharmaceutically important families of NPs and recent studies have revealed Antarctica to harbor endemic polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes, likely to be involved in the production of novel metabolites. Despite this, the diversity of secondary metabolites genes in Antarctica is still poorly explored. In this study, a computational bioprospection approach was employed to study the diversity and identity of PKS and NRPS genes to one of the most biodiverse areas in maritime Antarctica—Maxwell Bay. Amplicon sequencing of soil samples targeting ketosynthase (KS) and adenylation (AD) domains of PKS and NRPS genes, respectively, revealed abundant and unexplored chemical diversity in this peninsula. About 20% of AD domain sequences were only distantly related to characterized biosynthetic genes. Several PKS and NRPS genes were found to be closely associated to recently described metabolites including those from uncultured and candidate phyla. The combination of new approaches in computational biology and new culture-dependent and -independent strategies is thus critical for the recovery of the potential novel chemistry encoded in Antarctica microorganisms.
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Affiliation(s)
- Adriana Rego
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
- Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, 4050-313 Porto, Portugal
| | - António G. G. Sousa
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
| | - João P. Santos
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
- Institute F.-A. Forel, Earth and Environmental Sciences, Faculty of Sciences, University of Geneva, 66, Boulevard Carl-Vogt, 1211 Genève 4, Switzerland
| | - Francisco Pascoal
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
| | - João Canário
- Centro de Química Estrutural at Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
| | - Pedro N. Leão
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
- Correspondence: (P.N.L); (C.M.)
| | - Catarina Magalhães
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, 4450-208 Matosinhos, Portugal; (A.R.); (A.G.G.S.); (J.P.S.); (F.P.)
- Faculty of Sciences, University of Porto, 4150-179 Porto, Portugal
- School of Science, University of Waikato, Hamilton 3216, New Zealand
- Correspondence: (P.N.L); (C.M.)
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183
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Hatzenpichler R, Krukenberg V, Spietz RL, Jay ZJ. Next-generation physiology approaches to study microbiome function at single cell level. Nat Rev Microbiol 2020; 18:241-256. [PMID: 32055027 DOI: 10.1038/s41579-020-0323-1] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/06/2020] [Indexed: 12/14/2022]
Abstract
The function of cells in their native habitat often cannot be reliably predicted from genomic data or from physiology studies of isolates. Traditional experimental approaches to study the function of taxonomically and metabolically diverse microbiomes are limited by their destructive nature, low spatial resolution or low throughput. Recently developed technologies can offer new insights into cellular function in natural and human-made systems and how microorganisms interact with and shape the environments that they inhabit. In this Review, we provide an overview of these next-generation physiology approaches and discuss how the non-destructive analysis of cellular phenotypes, in combination with the separation of the target cells for downstream analyses, provide powerful new, complementary ways to study microbiome function. We anticipate that the widespread application of next-generation physiology approaches will transform the field of microbial ecology and dramatically improve our understanding of how microorganisms function in their native environment.
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Affiliation(s)
- Roland Hatzenpichler
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA.
| | - Viola Krukenberg
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Rachel L Spietz
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Zackary J Jay
- Department of Chemistry and Biochemistry, Center for Biofilm Engineering, and Thermal Biology Institute, Montana State University, Bozeman, MT, USA
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184
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Bartelme RP, Custer JM, Dupont CL, Espinoza JL, Torralba M, Khalili B, Carini P. Influence of Substrate Concentration on the Culturability of Heterotrophic Soil Microbes Isolated by High-Throughput Dilution-to-Extinction Cultivation. mSphere 2020; 5:e00024-20. [PMID: 31996418 PMCID: PMC6992367 DOI: 10.1128/msphere.00024-20] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 12/17/2022] Open
Abstract
The vast majority of microbes inhabiting oligotrophic shallow subsurface soil environments have not been isolated or studied under controlled laboratory conditions. In part, the challenges associated with isolating shallow subsurface microbes may persist because microbes in deeper soils are adapted to low nutrient availability or quality. Here, we use high-throughput dilution-to-extinction culturing to isolate shallow subsurface microbes from a conifer forest in Arizona, USA. We hypothesized that the concentration of heterotrophic substrates in microbiological growth medium would affect which microbial taxa were culturable from these soils. To test this, we diluted cells extracted from soil into one of two custom-designed defined growth media that differed by 100-fold in the concentration of amino acids and organic carbon. Across the two media, we isolated a total of 133 pure cultures, all of which were classified as Actinobacteria or Alphaproteobacteria The substrate availability dictated which actinobacterial phylotypes were culturable but had no significant effect on the culturability of Alphaproteobacteria We isolated cultures that were representative of the most abundant phylotype in the soil microbial community (Bradyrhizobium spp.) and representatives of five of the top 10 most abundant Actinobacteria phylotypes, including Nocardioides spp., Mycobacterium spp., and several other phylogenetically divergent lineages. Flow cytometry of nucleic acid-stained cells showed that cultures isolated on low-substrate medium had significantly lower nucleic acid fluorescence than those isolated on high-substrate medium. These results show that dilution-to-extinction is an effective method to isolate abundant soil microbes and that the concentration of substrates in culture medium influences the culturability of specific microbial lineages.IMPORTANCE Isolating environmental microbes and studying their physiology under controlled conditions are essential aspects of understanding their ecology. Subsurface ecosystems are typically nutrient-poor environments that harbor diverse microbial communities-the majority of which are thus far uncultured. In this study, we use modified high-throughput cultivation methods to isolate subsurface soil microbes. We show that a component of whether a microbe is culturable from subsurface soils is the concentration of growth substrates in the culture medium. Our results offer new insight into technical approaches and growth medium design that can be used to access the uncultured diversity of soil microbes.
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Affiliation(s)
- Ryan P Bartelme
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Joy M Custer
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
| | - Christopher L Dupont
- Department of Environment and Sustainability, J. Craig Venter Institute, La Jolla, California, USA
| | - Josh L Espinoza
- Department of Environment and Sustainability, J. Craig Venter Institute, La Jolla, California, USA
| | - Manolito Torralba
- Department of Environment and Sustainability, J. Craig Venter Institute, La Jolla, California, USA
| | - Banafshe Khalili
- Department of Ecology and Evolutionary Biology, University of California, Irvine, California, USA
| | - Paul Carini
- Department of Environmental Science, University of Arizona, Tucson, Arizona, USA
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185
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Najar IN, Sherpa MT, Das S, Thakur N. Bacterial diversity and functional metagenomics expounding the diversity of xenobiotics, stress, defense and CRISPR gene ontology providing eco-efficiency to Himalayan Hot Springs. Funct Integr Genomics 2020; 20:479-496. [PMID: 31897823 DOI: 10.1007/s10142-019-00723-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 10/17/2019] [Accepted: 11/05/2019] [Indexed: 11/26/2022]
Abstract
Sikkim is one of the bio-diverse states of India, which harbors diverse alkaline and sulfur rich hot springs in its vicinity. However, there is a dearth of data present in terms of microbial and its functional diversity as only a few hot springs have been studied in this area. Thus, in this regard, microbial and functional diversity of two hot springs by NGS, PLFA, and culture-independent approaches were carried out. PLFA and culture-dependent analysis was complementary as the Gram-positive bacteria were abundant in both the hot springs with the dominance of phylum Firmicutes with Geobacillus. Metagenomic analysis revealed the abundance of Proteobacteria, Actinobacteria, and Firmicutes in both hot springs. Functional metagenomics suggested that both Yumthang and Reshi hot spring possess a diverse set of genes analogous to stress such as genes allied to osmotic, heat shock, and acid stresses; defense analogies such as multidrug resistance efflux pump, multidrug transport system, and β-lactamase; and CRISPR analogues such as related to Cas1, Cas2, Cas3, cmr1-5 proteins, CT1972, and CT1133 gene families. The xenobiotic analogues were found against benzoate, nitrotolune, xylene, DDT, and chlorocyclohexane/chlorobenzene degradation. Thus, these defensive mechanisms against environmental and anthropogenic hiccups and hindrances provide the eco-efficiency to such thermal habitats. The higher enzymatic, degradation, defense, stress potential and the lower percentage identity (< 95%) of isolates encourage the further exploration and exploitation of these habitats for industrial and biotechnological purposes.
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Affiliation(s)
- Ishfaq Nabi Najar
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Tadong, Gangtok, Sikkim, 737102, India
| | - Mingma Thundu Sherpa
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Tadong, Gangtok, Sikkim, 737102, India
| | - Sayak Das
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Tadong, Gangtok, Sikkim, 737102, India
| | - Nagendra Thakur
- Department of Microbiology, School of Life Sciences, Sikkim University, 6th Mile, Samdur, Tadong, Gangtok, Sikkim, 737102, India.
- Department of Chemical Engineering and Biomolecular Engineering, Korean Advance Institute of Science and Technology, Daejeon, South Korea.
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186
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Dekas AE, Parada AE, Mayali X, Fuhrman JA, Wollard J, Weber PK, Pett-Ridge J. Characterizing Chemoautotrophy and Heterotrophy in Marine Archaea and Bacteria With Single-Cell Multi-isotope NanoSIP. Front Microbiol 2019; 10:2682. [PMID: 31920997 PMCID: PMC6927911 DOI: 10.3389/fmicb.2019.02682] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 11/05/2019] [Indexed: 11/28/2022] Open
Abstract
Characterizing and quantifying in situ metabolisms remains both a central goal and challenge for environmental microbiology. Here, we used a single-cell, multi-isotope approach to investigate the anabolic activity of marine microorganisms, with an emphasis on natural populations of Thaumarchaeota. After incubating coastal Pacific Ocean water with 13C-bicarbonate and 15N-amino acids, we used nanoscale secondary ion mass spectrometry (nanoSIMS) to isotopically screen 1,501 individual cells, and 16S rRNA amplicon sequencing to assess community composition. We established isotopic enrichment thresholds for activity and metabolic classification, and with these determined the percentage of anabolically active cells, the distribution of activity across the whole community, and the metabolic lifestyle—chemoautotrophic or heterotrophic—of each cell. Most cells (>90%) were anabolically active during the incubation, and 4–17% were chemoautotrophic. When we inhibited bacteria with antibiotics, the fraction of chemoautotrophic cells detected via nanoSIMS increased, suggesting archaea dominated chemoautotrophy. With fluorescence in situ hybridization coupled to nanoSIMS (FISH-nanoSIMS), we confirmed that most Thaumarchaeota were living chemoautotrophically, while bacteria were not. FISH-nanoSIMS analysis of cells incubated with dual-labeled (13C,15N-) amino acids revealed that most Thaumarchaeota cells assimilated amino-acid-derived nitrogen but not carbon, while bacteria assimilated both. This indicates that some Thaumarchaeota do not assimilate intact amino acids, suggesting intra-phylum heterogeneity in organic carbon utilization, and potentially their use of amino acids for nitrification. Together, our results demonstrate the utility of multi-isotope nanoSIMS analysis for high-throughput metabolic screening, and shed light on the activity and metabolism of uncultured marine archaea and bacteria.
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Affiliation(s)
- Anne E Dekas
- Department of Earth System Science, Stanford University, Stanford, CA, United States.,Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Alma E Parada
- Department of Earth System Science, Stanford University, Stanford, CA, United States.,Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Xavier Mayali
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Jed A Fuhrman
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States
| | - Jessica Wollard
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Peter K Weber
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
| | - Jennifer Pett-Ridge
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, United States
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187
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Strunecky O, Raabova L, Bernardova A, Ivanova AP, Semanova A, Crossley J, Kaftan D. Diversity of cyanobacteria at the Alaska North Slope with description of two new genera: Gibliniella and Shackletoniella. FEMS Microbiol Ecol 2019; 96:5645229. [DOI: 10.1093/femsec/fiz189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 11/26/2019] [Indexed: 11/12/2022] Open
Abstract
ABSTRACT
The diversity of cyanobacteria along the Alaskan North Slope was investigated. We isolated and cultivated 57 strains of cyanobacteria and sequenced a section of their rRNA operon containing a fragment of the 16S rRNA gene. Here, we describe 17 found species belonging mainly to families Coleofasciculaceae, Microcoleaceae, Oculatellaceae, Leptolyngbyaceae and to the order Synechococcales. In pursuing a conservative polyphasic approach, we utilized suggested thresholds in 16S rRNA gene differences in parallel with morphological differences between new and already described taxa for the description of new species and genera. Based on a combination of morphological, molecular and ecological analysis of collected and cultured strains we describe two genera Gibliniella and Shackletoniella as well as six cyanobacterial species; Cephalothrix alaskaensis, Tildeniella alaskaensis, Pseudophormidium americanum, Leptodesmis alaskaensis, Albertania alaskaensis and Nodosilinea alaskaensis. Here, a polyphasic approach was used to identify eight novel and nine established cyanobacterial taxa from a previously non–investigated region that uncovered a high degree of biodiversity in extreme polar environments.
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Affiliation(s)
- Otakar Strunecky
- University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, CENAKVA, Institute of Aquaculture and Protection of Waters, Na Sádkách 1780, 370 05 České Budějovice, Czech Republic
| | - Lenka Raabova
- Department of Biology, University of Ss. Cyril and Methodius, J. Herdu 2, 917 01 Trnava, Slovak Republic
| | - Alexandra Bernardova
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - Anna Pavlovna Ivanova
- University of South Bohemia in Ceske Budejovice, Faculty of Fisheries and Protection of Waters, CENAKVA, Institute of Aquaculture and Protection of Waters, Na Sádkách 1780, 370 05 České Budějovice, Czech Republic
| | - Alexandra Semanova
- Department of Biology, University of Ss. Cyril and Methodius, J. Herdu 2, 917 01 Trnava, Slovak Republic
| | - Joel Crossley
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
| | - David Kaftan
- Faculty of Science, University of South Bohemia, Branišovská 1760, 370 05 České Budějovice, Czech Republic
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188
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Megaw J, Kelly SA, Thompson TP, Skvortsov T, Gilmore BF. Profiling the microbial community of a Triassic halite deposit in Northern Ireland: an environment with significant potential for biodiscovery. FEMS Microbiol Lett 2019; 366:5645231. [DOI: 10.1093/femsle/fnz242] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 11/26/2019] [Indexed: 12/25/2022] Open
Abstract
ABSTRACTKilroot salt mine, a Triassic halite deposit located in County Antrim, Northern Ireland, is the only permanent hypersaline environment on the island of Ireland. In this study, the microbiome of this unstudied environment was profiled for the first time using conventional and enhanced culturing techniques, and culture independent metagenomic approaches. Using both conventional isolation plates and iChip devices, 89 halophilic archaeal isolates from six known genera, and 55 halophilic or halotolerant bacterial isolates from 18 genera were obtained, based on 16S rRNA gene sequencing. The archaeal isolates were similar to those previously isolated from other ancient halite deposits, and as expected, numerous genera were identified in the metagenome which were not represented among the culturable isolates. Preliminary screening of a selection of isolates from this environment identified antimicrobial activities against a panel of clinically important bacterial pathogens from 15 of the bacterial isolates and one of the archaea. This, alongside previous studies reporting the discovery of novel biocatalysts from the Kilroot mine microbiome, suggests that this environment may be a new, untapped source of of chemical diversity with high biodiscovery potential.
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Affiliation(s)
- Julianne Megaw
- Biofilm Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Stephen A Kelly
- Biofilm Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Thomas P Thompson
- Biofilm Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Timofey Skvortsov
- Biofilm Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
| | - Brendan F Gilmore
- Biofilm Research Group, School of Pharmacy, Queen's University Belfast, Medical Biology Centre, 97 Lisburn Road, Belfast BT9 7BL, UK
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189
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Rastelli E, Corinaldesi C, Dell'Anno A, Tangherlini M, Lo Martire M, Nishizawa M, Nomaki H, Nunoura T, Danovaro R. Drivers of Bacterial α- and β-Diversity Patterns and Functioning in Subsurface Hadal Sediments. Front Microbiol 2019; 10:2609. [PMID: 31798555 PMCID: PMC6868121 DOI: 10.3389/fmicb.2019.02609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/28/2019] [Indexed: 12/28/2022] Open
Abstract
Oceanic trenches at hadal (>6,000 m) depths are hot spots of organic matter deposition and mineralization and can host abundant and active bacterial assemblages. However, the factors able to shape their biodiversity and functioning remain largely unexplored, especially in subsurface sediments. Here, we investigated the patterns and drivers of benthic bacterial α- and β-diversity (i.e., OTU richness and turnover diversity) along the vertical profile down to 1.5 m sediment depth in the Izu-Bonin Trench (at ~10,000 m water depth). The protease and glucosidase enzymatic activity rates were also determined, as a proxy of organic matter degradation potential in the different sediment layers. Molecular fingerprinting based on automated ribosomal intergenic spacer analysis (ARISA) indicated that the α-diversity of bacterial assemblages remained high throughout the vertical profile and that the turnover (β-) diversity among sediment horizons reached values up to 90% of dissimilarity. Multivariate distance-based linear modeling (DISTLM) pointed out that the diversity and functioning of the hadal bacterial assemblages were influenced by the variability of environmental conditions (including the availability of organic resources and electron donors/acceptors) and of viral production rates along the sediment vertical profile. Based on our results, we can argue that the heterogeneity of physical-chemical features of the hadal sediments of the Izu-Bonin Trench contribute to increase the niches availability for different bacterial taxa, while viruses contribute to maintain high levels of bacterial turnover diversity and to enhance organic matter cycling in these extremely remote and isolated ecosystems.
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Affiliation(s)
- Eugenio Rastelli
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Cinzia Corinaldesi
- Department of Materials, Environmental Sciences and Urban Planning, Polytechnic University of Marche, Ancona, Italy
| | - Antonio Dell'Anno
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Michael Tangherlini
- Department of Research Infrastructures for Marine Biological Resources, Stazione Zoologica Anton Dohrn, Naples, Italy
| | - Marco Lo Martire
- Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
| | - Manabu Nishizawa
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Hidetaka Nomaki
- Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Takuro Nunoura
- Research Center for Bioscience and Nanoscience (CeBN), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
| | - Roberto Danovaro
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, Naples, Italy.,Department of Life and Environmental Sciences, Polytechnic University of Marche, Ancona, Italy
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190
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Cui L, Zhang D, Yang K, Zhang X, Zhu YG. Perspective on Surface-Enhanced Raman Spectroscopic Investigation of Microbial World. Anal Chem 2019; 91:15345-15354. [DOI: 10.1021/acs.analchem.9b03996] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Li Cui
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - DanDan Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Kai Yang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xian Zhang
- Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yong-Guan Zhu
- State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
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191
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Liu Y, Yao Q, Zhu H. Meta-16S rRNA Gene Phylogenetic Reconstruction Reveals the Astonishing Diversity of Cosmopolitan Myxobacteria. Microorganisms 2019; 7:microorganisms7110551. [PMID: 31717918 PMCID: PMC6920832 DOI: 10.3390/microorganisms7110551] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 11/06/2019] [Accepted: 11/06/2019] [Indexed: 11/29/2022] Open
Abstract
Numerous ecological studies on myxobacteria have been conducted, but their true diversity remains largely unknown. To bridge this gap, we implemented a comprehensive survey of diversity and distribution of myxobacteria by using 4997 publicly available 16S rRNA gene sequences (≥1200 bp) collected from several hundred sites across multiple countries and regions. In this study, the meta-16S rRNA gene phylogenetic reconstruction clearly revealed that these sequences could be classified into 998 species, 445 genera, 58 families, and 20 suborders, the great majority of which belonged to new taxa. Most cultured myxobacteria were strongly inclined to locate on the shallow branches of the phylogenetic tree; on the contrary, the majority of uncultured myxobacteria located on the deep branches. The geographical analysis of sequences based on their environmental categories clearly demonstrated that myxobacteria show a nearly cosmopolitan distribution, despite the presence of some habitat-specific taxa, especially at the genus and species levels. Among the abundant suborders, Suborder_4, Suborder_15, and Suborder_17 were more widely distributed in marine environments, while the remaining suborders preferred to reside in terrestrial ecosystems. In conclusion, this study profiles a clear framework of diversity and distribution of cosmopolitan myxobacteria and sheds light on the isolation of uncultured myxobacteria.
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Affiliation(s)
- Yang Liu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China;
| | - Qing Yao
- College of Horticulture, South China Agricultural University, Guangdong Province Key Laboratory of Microbial Signals and Disease Control, Guangdong Engineering Research Center for Grass Science, Guangdong Engineering Center for Litchi, Guangzhou 510642, China;
| | - Honghui Zhu
- State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangdong Open Laboratory of Applied Microbiology, Guangdong Microbial Culture Collection Center (GDMCC), Guangdong Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou 510070, China;
- Correspondence: ; Tel.: +86-020-8713-7669
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192
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López-Mondéjar R, Algora C, Baldrian P. Lignocellulolytic systems of soil bacteria: A vast and diverse toolbox for biotechnological conversion processes. Biotechnol Adv 2019; 37:107374. [DOI: 10.1016/j.biotechadv.2019.03.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/06/2019] [Accepted: 03/21/2019] [Indexed: 12/12/2022]
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193
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Santoro AE, Kellom M, Laperriere SM. Contributions of single-cell genomics to our understanding of planktonic marine archaea. Philos Trans R Soc Lond B Biol Sci 2019; 374:20190096. [PMID: 31587640 DOI: 10.1098/rstb.2019.0096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Single-cell genomics has transformed many fields of biology, marine microbiology included. Here, we consider the impact of single-cell genomics on a specific group of marine microbes-the planktonic marine archaea. Despite single-cell enabled discoveries of novel metabolic function in the marine thaumarchaea, population-level investigations are hindered by an overall lower than expected recovery of thaumarchaea in single-cell studies. Metagenome-assembled genomes have so far been a more useful method for accessing genome-resolved insights into the Marine Group II euryarchaea. Future progress in the application of single-cell genomics to archaeal biology in the ocean would benefit from more targeted sorting approaches, and a more systematic investigation of potential biases against archaea in single-cell workflows including cell lysis, genome amplification and genome screening. This article is part of a discussion meeting issue 'Single cell ecology'.
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Affiliation(s)
- A E Santoro
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106-9620, USA
| | - M Kellom
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106-9620, USA
| | - S M Laperriere
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA 93106-9620, USA
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195
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Salmaso N. Effects of Habitat Partitioning on the Distribution of Bacterioplankton in Deep Lakes. Front Microbiol 2019; 10:2257. [PMID: 31636614 PMCID: PMC6788347 DOI: 10.3389/fmicb.2019.02257] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 09/17/2019] [Indexed: 12/04/2022] Open
Abstract
In deep lakes, many investigations highlighted the existence of exclusive groups of bacteria adapted to deep oxygenated and hypoxic and anoxic hypolimnia. Nevertheless, the extent of bacterial strain diversity has been much less scrutinized. This aspect is essential for an unbiased estimation of genetic variation, biodiversity, and population structure, which are essential for studying important research questions such as biogeographical patterns, temporal and spatial variability and the environmental factors affecting this variability. This study investigated the bacterioplankton community in the epilimnetic layers and in the oxygenated and hypoxic/anoxic hypolimnia of five large and deep lakes located at the southern border of the Alps using high throughput sequencing (HTS) analyses (16S rDNA) and identification of amplicon sequence variants (ASVs) resolving reads differing by as little as one nucleotide. The study sites, which included two oligomictic (Garda and Como) and three meromictic lakes (Iseo, Lugano, and Idro) with maximum depths spanning from 124 to 410 m, were chosen among large lakes to represent an oxic-hypoxic gradient. The analyses showed the existence of several unique ASVs in the three layers of the five lakes. In the case of cyanobacteria, this confirmed previous analyses made at the level of strains or based on oligotyping methods. As expected, the communities in the hypoxic/anoxic monimolimnia showed a strong differentiation from the oxygenated layer, with the exclusive presence in single lakes of several unique ASVs. In the meromictic lakes, results supported the hypothesis that the formation of isolated monimolimnia sustained the development of highly diversified bacterial communities through ecological selection, leading to the establishment of distinctive biodiversity zones. The genera identified in these layers are well-known to activate a wide range of redox reactions at low O2 conditions. As inferred from 16S rDNA data, the highly diversified and coupled processes sustained by the monimolimnetic microbiota are essential ecosystem services that enhance mineralization of organic matter and formation of reduced compounds, and also abatement of undesirable greenhouse gasses.
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Affiliation(s)
- Nico Salmaso
- Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Italy
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196
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Abstract
While most bacterial and archaeal taxa living in surface soils remain undescribed, this problem is exacerbated in deeper soils, owing to the unique oligotrophic conditions found in the subsurface. Additionally, previous studies of soil microbiomes have focused almost exclusively on surface soils, even though the microbes living in deeper soils also play critical roles in a wide range of biogeochemical processes. We examined soils collected from 20 distinct profiles across the United States to characterize the bacterial and archaeal communities that live in subsurface soils and to determine whether there are consistent changes in soil microbial communities with depth across a wide range of soil and environmental conditions. We found that bacterial and archaeal diversity generally decreased with depth, as did the degree of similarity of microbial communities to those found in surface horizons. We observed five phyla that consistently increased in relative abundance with depth across our soil profiles: Chloroflexi, Nitrospirae, Euryarchaeota, and candidate phyla GAL15 and Dormibacteraeota (formerly AD3). Leveraging the unusually high abundance of Dormibacteraeota at depth, we assembled genomes representative of this candidate phylum and identified traits that are likely to be beneficial in low-nutrient environments, including the synthesis and storage of carbohydrates, the potential to use carbon monoxide (CO) as a supplemental energy source, and the ability to form spores. Together these attributes likely allow members of the candidate phylum Dormibacteraeota to flourish in deeper soils and provide insight into the survival and growth strategies employed by the microbes that thrive in oligotrophic soil environments.IMPORTANCE Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons are still important components of terrestrial ecosystems. By studying 20 soil profiles across the United States, we documented consistent changes in soil bacterial and archaeal communities with depth. Deeper soils harbored communities distinct from those of the more commonly studied surface horizons. Most notably, we found that the candidate phylum Dormibacteraeota (formerly AD3) was often dominant in subsurface soils, and we used genomes from uncultivated members of this group to identify why these taxa are able to thrive in such resource-limited environments. Simply digging deeper into soil can reveal a surprising number of novel microbes with unique adaptations to oligotrophic subsurface conditions.
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197
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Amend JP, LaRowe DE. Minireview: demystifying microbial reaction energetics. Environ Microbiol 2019; 21:3539-3547. [PMID: 31403238 PMCID: PMC6852080 DOI: 10.1111/1462-2920.14778] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/07/2019] [Accepted: 08/08/2019] [Indexed: 12/04/2022]
Abstract
The biology literature is rife with misleading information on how to quantify catabolic reaction energetics. The principal misconception is that the sign and value of the standard Gibbs energy ( Δ G r 0 ) define the direction and energy yield of a reaction; they do not. Δ G r 0 is one part of the actual Gibbs energy of a reaction (ΔGr ), with a second part accounting for deviations from the standard composition. It is also frequently assumed that Δ G r 0 applies only to 25 °C and 1 bar; it does not. Δ G r 0 is a function of temperature and pressure. Here, we review how to determine ΔGr as a function of temperature, pressure and chemical composition for microbial catabolic reactions, including a discussion of the effects of ionic strength on ΔGr and highlighting the large effects when multi-valent ions are part of the reaction. We also calculate ΔGr for five example catabolisms at specific environmental conditions: aerobic respiration of glucose in freshwater, anaerobic respiration of acetate in marine sediment, hydrogenotrophic methanogenesis in a laboratory batch reactor, anaerobic ammonia oxidation in a wastewater reactor and aerobic pyrite oxidation in acid mine drainage. These examples serve as templates to determine the energy yields of other catabolic reactions at environmentally relevant conditions.
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Affiliation(s)
- Jan P. Amend
- Department of Biological SciencesUniversity of Southern CaliforniaLos AngelesCA90089USA
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCA90089USA
| | - Douglas E. LaRowe
- Department of Earth SciencesUniversity of Southern CaliforniaLos AngelesCA90089USA
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198
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Kinetics and Identities of Extracellular Peptidases in Subsurface Sediments of the White Oak River Estuary, North Carolina. Appl Environ Microbiol 2019; 85:AEM.00102-19. [PMID: 31324636 PMCID: PMC6752024 DOI: 10.1128/aem.00102-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 07/14/2019] [Indexed: 11/20/2022] Open
Abstract
Anoxic subsurface sediments contain communities of heterotrophic microorganisms that metabolize organic carbon at extraordinarily low rates. In order to assess the mechanisms by which subsurface microorganisms access detrital sedimentary organic matter, we measured kinetics of a range of extracellular peptidases in anoxic sediments of the White Oak River Estuary, NC. Nine distinct peptidase substrates were enzymatically hydrolyzed at all depths. Potential peptidase activities (V max) decreased with increasing sediment depth, although V max expressed on a per-cell basis was approximately the same at all depths. Half-saturation constants (Km ) decreased with depth, indicating peptidases that functioned more efficiently at low substrate concentrations. Potential activities of extracellular peptidases acting on molecules that are enriched in degraded organic matter (d-phenylalanine and l-ornithine) increased relative to enzymes that act on l-phenylalanine, further suggesting microbial community adaptation to access degraded organic matter. Nineteen classes of predicted, exported peptidases were identified in genomic data from the same site, of which genes for class C25 (gingipain-like) peptidases represented more than 40% at each depth. Methionine aminopeptidases, zinc carboxypeptidases, and class S24-like peptidases, which are involved in single-stranded-DNA repair, were also abundant. These results suggest a subsurface heterotrophic microbial community that primarily accesses low-quality detrital organic matter via a diverse suite of well-adapted extracellular enzymes.IMPORTANCE Burial of organic carbon in marine and estuarine sediments represents a long-term sink for atmospheric carbon dioxide. Globally, ∼40% of organic carbon burial occurs in anoxic estuaries and deltaic systems. However, the ultimate controls on the amount of organic matter that is buried in sediments, versus oxidized into CO2, are poorly constrained. In this study, we used a combination of enzyme assays and metagenomic analysis to identify how subsurface microbial communities catalyze the first step of proteinaceous organic carbon degradation. Our results show that microbial communities in deeper sediments are adapted to access molecules characteristic of degraded organic matter, suggesting that those heterotrophs are adapted to life in the subsurface.
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199
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Quantitatively Partitioning Microbial Genomic Traits among Taxonomic Ranks across the Microbial Tree of Life. mSphere 2019; 4:4/4/e00446-19. [PMID: 31462411 PMCID: PMC6714891 DOI: 10.1128/msphere.00446-19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recently, there has been great progress in defining a complete taxonomy of bacteria and archaea, which has been enabled by improvements in DNA sequencing technology and new bioinformatic techniques. A new, algorithmically defined microbial tree of life describes those linkages, relying solely on genetic data, which raises the issue of how microbial traits relate to taxonomy. Here, we adopted cluster of orthologous group functional categories as a scheme to describe the genomic contents of microbes, a method that can be applied to any microbial lineage for which genomes are available. This simple approach allows quantitative comparisons between microbial genomes with different gene compositions from across the microbial tree of life. Our observations demonstrate statistically significant patterns in cluster of orthologous group functional categories at taxonomic levels that span the range from domain to genus. Widely used microbial taxonomies, such as the NCBI taxonomy, are based on a combination of sequence homology among conserved genes and historically accepted taxonomies, which were developed based on observable traits such as morphology and physiology. A recently proposed alternative taxonomy database, the Genome Taxonomy Database (GTDB), incorporates only sequence homology of conserved genes and attempts to partition taxonomic ranks such that each rank implies the same amount of evolutionary distance, regardless of its position on the phylogenetic tree. This provides the first opportunity to completely separate taxonomy from traits and therefore to quantify how taxonomic rank corresponds to traits across the microbial tree of life. We quantified the relative abundances of clusters of orthologous group functional categories (COG-FCs) as a proxy for traits within the lineages of 13,735 cultured and uncultured microbial lineages from a custom-curated genome database. On average, 41.4% of the variation in COG-FC relative abundance is explained by taxonomic rank, with domain, phylum, class, order, family, and genus explaining, on average, 3.2%, 14.6%, 4.1%, 9.2%, 4.8%, and 5.5% of the variance, respectively (P < 0.001 for all). To our knowledge, this is the first work to quantify the variance in metabolic potential contributed by individual taxonomic ranks. A qualitative comparison between the COG-FC relative abundances and genus-level phylogenies, generated from published concatenated protein sequence alignments, further supports the idea that metabolic potential is taxonomically coherent at higher taxonomic ranks. The quantitative analyses presented here characterize the integral relationship between diversification of microbial lineages and the metabolisms which they host. IMPORTANCE Recently, there has been great progress in defining a complete taxonomy of bacteria and archaea, which has been enabled by improvements in DNA sequencing technology and new bioinformatic techniques. A new, algorithmically defined microbial tree of life describes those linkages, relying solely on genetic data, which raises the issue of how microbial traits relate to taxonomy. Here, we adopted cluster of orthologous group functional categories as a scheme to describe the genomic contents of microbes, a method that can be applied to any microbial lineage for which genomes are available. This simple approach allows quantitative comparisons between microbial genomes with different gene compositions from across the microbial tree of life. Our observations demonstrate statistically significant patterns in cluster of orthologous group functional categories at taxonomic levels that span the range from domain to genus.
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200
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High proportions of bacteria and archaea across most biomes remain uncultured. ISME JOURNAL 2019; 13:3126-3130. [PMID: 31388130 PMCID: PMC6863901 DOI: 10.1038/s41396-019-0484-y] [Citation(s) in RCA: 186] [Impact Index Per Article: 37.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/20/2019] [Accepted: 07/11/2019] [Indexed: 01/08/2023]
Abstract
A recent paper by Martiny argues that "high proportions" of bacteria in diverse Earth environments have been cultured. Here we reanalyze a portion of the data in that paper, and argue that the conclusion is based on several technical errors, most notably a calculation of sequence similarity that does not account for sequence gaps, and the reliance on 16S rRNA gene amplicons that are known to be biased towards cultured organisms. We further argue that the paper is also based on a conceptual error: namely, that sequence similarity cannot be used to infer "culturability" because one cannot infer physiology from 16S rRNA gene sequences. Combined with other recent, more reliable studies, the evidence supports the conclusion that most bacterial and archaeal taxa remain uncultured.
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