1
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Schloss PD. Rarefaction is currently the best approach to control for uneven sequencing effort in amplicon sequence analyses. mSphere 2024; 9:e0035423. [PMID: 38251877 PMCID: PMC10900887 DOI: 10.1128/msphere.00354-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 12/18/2023] [Indexed: 01/23/2024] Open
Abstract
Considering it is common to find as much as 100-fold variation in the number of 16S rRNA gene sequences across samples in a study, researchers need to control for the effect of uneven sequencing effort. How to do this has become a contentious question. Some have argued that rarefying or rarefaction is "inadmissible" because it omits valid data. A number of alternative approaches have been developed to normalize and rescale the data that purport to be invariant to the number of observations. I generated community distributions based on 12 published data sets where I was able to assess the ability of multiple methods to control for uneven sequencing effort. Rarefaction was the only method that could control for variation in uneven sequencing effort when measuring commonly used alpha and beta diversity metrics. Next, I compared the false detection rate and power to detect true differences between simulated communities with a known effect size using various alpha and beta diversity metrics. Although all methods of controlling for uneven sequencing effort had an acceptable false detection rate when samples were randomly assigned to two treatment groups, rarefaction was consistently able to control for differences in sequencing effort when sequencing depth was confounded with treatment group. Finally, the statistical power to detect differences in alpha and beta diversity metrics was consistently the highest when using rarefaction. These simulations underscore the importance of using rarefaction to normalize the number of sequences across samples in amplicon sequencing analyses. IMPORTANCE Sequencing 16S rRNA gene fragments has become a fundamental tool for understanding the diversity of microbial communities and the factors that affect their diversity. Due to technical challenges, it is common to observe wide variation in the number of sequences that are collected from different samples within the same study. However, the diversity metrics used by microbial ecologists are sensitive to differences in sequencing effort. Therefore, tools are needed to control for the uneven levels of sequencing. This simulation-based analysis shows that despite a longstanding controversy, rarefaction is the most robust approach to control for uneven sequencing effort. The controversy started because of confusion over the definition of rarefaction and violation of assumptions that are made by methods that have been borrowed from other fields. Microbial ecologists should use rarefaction.
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Affiliation(s)
- Patrick D. Schloss
- Department of Microbiology & Immunology, University of Michigan, Ann Arbor, Michigan, USA
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2
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Mo S, Li J, Li B, Kashif M, Nie S, Liao J, Su G, Jiang Q, Yan B, Jiang C. L-Cysteine Synthase Enhanced Sulfide Biotransformation in Subtropical Marine Mangrove Sediments as Revealed by Metagenomics Analysis. WATER 2021; 13:3053. [DOI: 10.3390/w13213053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
High sulfides concentrations can be poisonous to environment because of anthropogenic waste production or natural occurrences. How to elucidate the biological transformation mechanisms of sulfide pollutants in the subtropical marine mangrove ecosystem has gained increased interest. Thus, in the present study, the sulfide biotransformation in subtropical mangroves ecosystem was accurately evaluated using metagenomic sequencing and quantitative polymerase chain reaction analysis. Most abundant genes were related to the organic sulfur transformation. Furthermore, an ecological model of sulfide conversion was constructed. Total phosphorus was the dominant environmental factor that drove the sulfur cycle and microbial communities. We compared mangrove and non-mangrove soils and found that the former enhanced metabolism that was related to sulfate reduction when compared to the latter. Total organic carbon, total organic nitrogen, iron, and available sulfur were the key environmental factors that effectively influenced the dissimilatory sulfate reduction. The taxonomic assignment of dissimilatory sulfate-reducing genes revealed that Desulfobacterales and Chromatiales were mainly responsible for sulfate reduction. Chromatiales were most sensitive to environmental factors. The high abundance of cysE and cysK could contribute to the coping of the microbial community with the toxic sulfide produced by Desulfobacterales. Collectively, these findings provided a theoretical basis for the mechanism of the sulfur cycle in subtropical mangrove ecosystems.
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3
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Mo S, Li J, Li B, Kashif M, Nie S, Liao J, Su G, Jiang Q, Yan B, Jiang C. L-Cysteine Synthase Enhanced Sulfide Biotransformation in Subtropical Marine Mangrove Sediments as Revealed by Metagenomics Analysis. WATER 2021; 13:3053. [DOI: https:/doi.org/10.3390/w13213053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
High sulfides concentrations can be poisonous to environment because of anthropogenic waste production or natural occurrences. How to elucidate the biological transformation mechanisms of sulfide pollutants in the subtropical marine mangrove ecosystem has gained increased interest. Thus, in the present study, the sulfide biotransformation in subtropical mangroves ecosystem was accurately evaluated using metagenomic sequencing and quantitative polymerase chain reaction analysis. Most abundant genes were related to the organic sulfur transformation. Furthermore, an ecological model of sulfide conversion was constructed. Total phosphorus was the dominant environmental factor that drove the sulfur cycle and microbial communities. We compared mangrove and non-mangrove soils and found that the former enhanced metabolism that was related to sulfate reduction when compared to the latter. Total organic carbon, total organic nitrogen, iron, and available sulfur were the key environmental factors that effectively influenced the dissimilatory sulfate reduction. The taxonomic assignment of dissimilatory sulfate-reducing genes revealed that Desulfobacterales and Chromatiales were mainly responsible for sulfate reduction. Chromatiales were most sensitive to environmental factors. The high abundance of cysE and cysK could contribute to the coping of the microbial community with the toxic sulfide produced by Desulfobacterales. Collectively, these findings provided a theoretical basis for the mechanism of the sulfur cycle in subtropical mangrove ecosystems.
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4
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Ahmad M, Ling J, Yang Q, Sajjad W, Zhou W, Yin J, Dong J. Insight into Bacterial Community Responses to Polycyclic Aromatic Hydrocarbons and the Degradation Potentials of Three Bacterial Isolates in Seagrass Halophila ovalis Sediments. Curr Microbiol 2021; 78:4084-4097. [PMID: 34687349 DOI: 10.1007/s00284-021-02670-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 09/26/2021] [Indexed: 11/28/2022]
Abstract
Seagrass meadows constitute a prestigious ecosystem in the marine environment, providing valuable ecological and commercial services. Among the various causes, pollutions are considered one of the significant reasons for seagrass decline globally. This study investigates the impacts of polycyclic aromatic hydrocarbons mixture (pyrene, phenanthrene, and fluorene) on bacterial communities in Halophila ovalis sediments. The seagrass sediment bacterial microbiome was evaluated in a batch culture experiment by Illumina MiSeq sequencing. Culture-able bacterial strains were isolated and characterized by 16S rRNA gene sequencing. The results demonstrated an excellent alpha diversity in the original sediments with a Shannon index of (8.078) compared to the subsequent control group (5.908) and PAH-treated group (PAH-T) (4.916). Three phyla, Proteobacteria, Firmicutes, and Bacteroidetes, were detected in high abundance in the control and PAH-T groups. However, a significant difference (P < 0.05) was observed at the genus level between control and PAH-T group bacterial consortia. Pseudomonas, Mycobacterium, Idiomarina, Hydrogenophaga, Alteromonas, Sphingobacterium, and several others were highly abundant in PAH-T groups. Most of the culture-able isolates recovered in this study showed the closest resemblance to previously identified hydrocarbon-degrading bacteria. Among the three strains, Mix-16 (Citricoccus yambaruensis) and Mix-20 (Gordonia rubripertincta) showed a higher degradation of PAHs than Mix-19 (Isoptericola halotolerans) in the monoculture experiment. The most increased degradation of PAHs was recorded in the co-culture experiment. The present work revealed that PAHs could act as environmental stress and can influence bacterial community succession. Moreover, the co-culture strategy significantly enhanced the biodegradation of PAHs.
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Affiliation(s)
- Manzoor Ahmad
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.,Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China.,Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Juan Ling
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China. .,Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China. .,Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China. .,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China.
| | - Qingsong Yang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.,Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China.,Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China
| | - Wasim Sajjad
- Department of Biological Sciences, National University of Medical Sciences, Rawalpindi, 46000, Pakistan
| | - Weiguo Zhou
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.,Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China.,Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China
| | - Jianping Yin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China.,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China
| | - Junde Dong
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, China. .,Key Laboratory of Tropical Marine Biotechnology of Hainan Province, Sanya Institute of Oceanology, SCSIO, Sanya, 572000, China. .,Sanya National Marine Ecosystem Research Station, Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China. .,Innovation Academy of South China Sea Ecology and Environmental Engineering, Chinese Academy of Sciences, Guangzhou, 511458, China.
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5
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Ma X, Olsen JL, Reusch TBH, Procaccini G, Kudrna D, Williams M, Grimwood J, Rajasekar S, Jenkins J, Schmutz J, Van de Peer Y. Improved chromosome-level genome assembly and annotation of the seagrass, Zostera marina (eelgrass). F1000Res 2021; 10:289. [PMID: 34621505 PMCID: PMC8482049 DOI: 10.12688/f1000research.38156.1] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2021] [Indexed: 12/12/2022] Open
Abstract
Background: Seagrasses (Alismatales) are the only fully marine angiosperms.
Zostera marina (eelgrass) plays a crucial role in the functioning of coastal marine ecosystems and global carbon sequestration. It is the most widely studied seagrass and has become a marine model system for exploring adaptation under rapid climate change. The original draft genome (v.1.0) of the seagrass
Z.
marina (L.) was based on a combination of Illumina mate-pair libraries and fosmid-ends. A total of 25.55 Gb of Illumina and 0.14 Gb of Sanger sequence was obtained representing 47.7× genomic coverage. The assembly resulted in ~2000 unordered scaffolds (L50 of 486 Kb), a final genome assembly size of 203MB, 20,450 protein coding genes and 63% TE content. Here, we present an upgraded chromosome-scale genome assembly and compare v.1.0 and the new v.3.1, reconfirming previous results from Olsen et al. (2016), as well as pointing out new findings. Methods: The same high molecular weight DNA used in the original sequencing of the Finnish clone was used. A high-quality reference genome was assembled with the MECAT assembly pipeline combining PacBio long-read sequencing and Hi-C scaffolding. Results: In total, 75.97 Gb PacBio data was produced. The final assembly comprises six pseudo-chromosomes and 304 unanchored scaffolds with a total length of 260.5Mb and an N50 of 34.6 MB, showing high contiguity and few gaps (~0.5%). 21,483 protein-encoding genes are annotated in this assembly, of which 20,665 (96.2%) obtained at least one functional assignment based on similarity to known proteins. Conclusions: As an important marine angiosperm, the improved
Z. marina genome assembly will further assist evolutionary, ecological, and comparative genomics at the chromosome level. The new genome assembly will further our understanding into the structural and physiological adaptations from land to marine life.
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Affiliation(s)
- Xiao Ma
- Department of Plant Biotechnology and Bioinformatics, Ghent University - Center for Plant Systems Biology, VIB, Ghent, 9052, Belgium
| | - Jeanine L Olsen
- Groningen Institute of Evolutionary Life Sciences, Groningen, 9747 AG, The Netherlands
| | - Thorsten B H Reusch
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Marine Evolutionary Ecology, Kiel, 24105, Germany
| | - Gabriele Procaccini
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Napoli, 80123, Italy
| | - Dave Kudrna
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Lab, Berkeley, CA, USA
| | | | - Jane Grimwood
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Shanmugam Rajasekar
- Arizona Genomics Institute, School of Plant Sciences, University of Arizona Tucson, Tucson, AZ, 85721, USA
| | - Jerry Jenkins
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Jeremy Schmutz
- Department of Energy Joint Genome Institute, Lawrence Berkeley National Lab, Berkeley, CA, USA.,HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University - Center for Plant Systems Biology, VIB, Ghent, 9052, Belgium.,Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa.,College of Horticulture, Nanjing Agricultural University, Nanjing, 210014, China
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6
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Wu J, Hong Y, Liu X, Hu Y. Variations in nitrogen removal rates and microbial communities over sediment depth in Daya Bay, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 286:117267. [PMID: 33965803 DOI: 10.1016/j.envpol.2021.117267] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Revised: 04/08/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
Depth-related variations in the activities, abundances, and community composition of denitrification and anaerobic ammonia oxidation (anammox) bacteria in coastal sediment cores remain poorly understood. In this study, we used 15N-labelled incubation, quantitative polymerase chain reaction (qPCR), and high-throughput sequencing techniques to reveal the structure and function of denitrifiers and anammox bacteria in sediment cores (almost 100 cm depth) collected in winter and summer from four locations in Daya Bay. The results indicated that the activities and abundances of both denitrifiers and anammox bacteria were detected even in deeper sediments with low concentrations of dissolved inorganic nitrogen (DIN). The potential rates, abundances, and community compositions of denitrifiers and anammox bacteria only varied spatially. In the surface sediment (top 2 cm), denitrifiers had significantly higher activities and abundances than anammox bacteria, but the relative contribution of anammox bacteria to nitrogen loss increased to >60% in the subsurface sediments. Phylogenetic analysis revealed that nirS-type denitrifiers were affiliated to 10 different clusters and Candidatus Scalindua dominated the anammox community in the whole sediments. Furthermore, both denitrification and anammox bacterial communities in the subsurface sediments were distinct from those in the surface sediments. Coupled nitrification and denitrification or anammox may play significant roles in removing fixed N, and the availability of electronic acceptors (e.g. nitrite and nitrate) strongly influenced the N loss activities in the subsurface sediment, emphasising its role as a sink for buried N.
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Affiliation(s)
- Jiapeng Wu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Yiguo Hong
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China; School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China.
| | - Xiaohan Liu
- Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou, 510006, China
| | - Yaohao Hu
- State Key Laboratory of Tropical Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
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7
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Abstract
Seagrasses are marine flowering plants that provide critical ecosystem services in coastal environments worldwide. Marine fungi are often overlooked in microbiome and seagrass studies, despite terrestrial fungi having critical functional roles as decomposers, pathogens, or endophytes in global ecosystems. Here, we characterize the distribution of fungi associated with the seagrass Zostera marina, using leaves, roots, and rhizosphere sediment from 16 locations across its full biogeographic range. Using high-throughput sequencing of the ribosomal internal transcribed spacer (ITS) region and 18S rRNA gene, we first measured fungal community composition and diversity. We then tested hypotheses of neutral community assembly theory and the degree to which deviations suggested that amplicon sequence variants (ASVs) were plant selected or dispersal limited. Finally, we identified a core mycobiome and investigated the global distribution of differentially abundant ASVs. We found that the fungal community is significantly different between sites and that the leaf mycobiome follows a weak but significant pattern of distance decay in the Pacific Ocean. Generally, there was evidence for both deterministic and stochastic factors contributing to community assembly of the mycobiome, with most taxa assembling through stochastic processes. The Z. marina core leaf and root mycobiomes were dominated by unclassified Sordariomycetes spp., unclassified Chytridiomycota lineages (including Lobulomycetaceae spp.), unclassified Capnodiales spp., and Saccharomyces sp. It is clear from the many unclassified fungal ASVs and fungal functional guilds that knowledge of marine fungi is still rudimentary. Further studies characterizing seagrass-associated fungi are needed to understand the roles of these microorganisms generally and when associated with seagrasses. IMPORTANCE Fungi have important functional roles when associated with land plants, yet very little is known about the roles of fungi associated with marine plants, like seagrasses. In this study, we report the results of a global effort to characterize the fungi associated with the seagrass Zostera marina across its full biogeographic range. Although we defined a putative global core fungal community, it is apparent from the many fungal sequences and predicted functional guilds that had no matches to existing databases that general knowledge of seagrass-associated fungi and marine fungi is lacking. This work serves as an important foundational step toward future work investigating the functional ramifications of fungi in the marine ecosystem.
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8
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The Seagrass Holobiont: What We Know and What We Still Need to Disclose for Its Possible Use as an Ecological Indicator. WATER 2021. [DOI: 10.3390/w13040406] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Microbes and seagrass establish symbiotic relationships constituting a functional unit called the holobiont that reacts as a whole to environmental changes. Recent studies have shown that the seagrass microbial associated community varies according to host species, environmental conditions and the host’s health status, suggesting that the microbial communities respond rapidly to environmental disturbances and changes. These changes, dynamics of which are still far from being clear, could represent a sensitive monitoring tool and ecological indicator to detect early stages of seagrass stress. In this review, the state of art on seagrass holobiont is discussed in this perspective, with the aim of disentangling the influence of different factors in shaping it. As an example, we expand on the widely studied Halophila stipulacea’s associated microbial community, highlighting the changing and the constant components of the associated microbes, in different environmental conditions. These studies represent a pivotal contribution to understanding the holobiont’s dynamics and variability pattern, and to the potential development of ecological/ecotoxicological indices. The influences of the host’s physiological and environmental status in changing the seagrass holobiont, alongside the bioinformatic tools for data analysis, are key topics that need to be deepened, in order to use the seagrass-microbial interactions as a source of ecological information.
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9
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Li C, Zhong Z, Wang W, Wang H, Yan G, Dong W, Chu Z, Wang H, Chang Y. Distribution characteristics of nitrogen and the related microbial community in the surface sediments of the Songhua River. RSC Adv 2021; 11:26721-26731. [PMID: 35480017 PMCID: PMC9037357 DOI: 10.1039/d1ra04903h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/26/2021] [Indexed: 11/21/2022] Open
Abstract
In this study, temporal and spatial distribution of nitrogen in the Songhua River sediments and distribution characteristics of related microbes as well as the relationship between them were investigated.
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Affiliation(s)
- Congyu Li
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
| | - Zhen Zhong
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
- ChangZhou JiangRun Environmental Protection Technology Co., Ltd
| | - Wenfu Wang
- Shangcai County Environmental Monitoring Station
- China
| | - Haiyan Wang
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
| | - Guokai Yan
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
| | - Weiyang Dong
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
| | - Zhaosheng Chu
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration
- Chinese Research Academy of Environmental Sciences
- Beijing 100012
- PR China
| | - Huan Wang
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
| | - Yang Chang
- Research Center of Environmental Pollution Control Technology
- Chinese Research Academy of Environmental Science
- Beijing 100012
- PR China
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10
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Ettinger CL, Eisen JA. Fungi, bacteria and oomycota opportunistically isolated from the seagrass, Zostera marina. PLoS One 2020; 15:e0236135. [PMID: 32697800 PMCID: PMC7375540 DOI: 10.1371/journal.pone.0236135] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 06/29/2020] [Indexed: 01/18/2023] Open
Abstract
Fungi in the marine environment are often neglected as a research topic, despite that fungi having critical roles on land as decomposers, pathogens or endophytes. Here we used culture-dependent methods to survey the fungi associated with the seagrass, Zostera marina, also obtaining bacteria and oomycete isolates in the process. A total of 108 fungi, 40 bacteria and 2 oomycetes were isolated. These isolates were then taxonomically identified using a combination of molecular and phylogenetic methods. The majority of the fungal isolates were classified as belonging to the classes Eurotiomycetes, Dothideomycetes, and Sordariomycetes. Most fungal isolates were habitat generalists like Penicillium sp. and Cladosporium sp., but we also cultured a diverse set of rare taxa including possible habitat specialists like Colletotrichum sp. which may preferentially associate with Z. marina leaf tissue. Although the bulk of bacterial isolates were identified as being from known ubiquitous marine lineages, we also obtained several Actinomycetes isolates and a Phyllobacterium sp. We identified two oomycetes, another understudied group of marine microbial eukaryotes, as Halophytophthora sp. which may be opportunistic pathogens or saprophytes of Z. marina. Overall, this study generates a culture collection of fungi which adds to knowledge of Z. marina associated fungi and highlights a need for more investigation into the functional and evolutionary roles of microbial eukaryotes associated with seagrasses.
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Affiliation(s)
- Cassandra L. Ettinger
- Genome Center, University of California, Davis, CA, United States of America
- Department of Evolution and Ecology, University of California, Davis, CA, United States of America
| | - Jonathan A. Eisen
- Genome Center, University of California, Davis, CA, United States of America
- Department of Evolution and Ecology, University of California, Davis, CA, United States of America
- Department of Medical Microbiology and Immunology, University of California, Davis, CA, United States of America
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11
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Rapid Metabolome and Bioactivity Profiling of Fungi Associated with the Leaf and Rhizosphere of the Baltic Seagrass Zostera marina. Mar Drugs 2019; 17:md17070419. [PMID: 31330983 PMCID: PMC6669648 DOI: 10.3390/md17070419] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 07/15/2019] [Accepted: 07/16/2019] [Indexed: 01/30/2023] Open
Abstract
Zostera marina (eelgrass) is a marine foundation species with key ecological roles in coastal habitats. Its bacterial microbiota has been well studied, but very little is known about its mycobiome. In this study, we have isolated and identified 13 fungal strains, dominated by Penicillium species (10 strains), from the leaf and the root rhizosphere of Baltic Z. marina. The organic extracts of the fungi that were cultured by an OSMAC (One-Strain–Many-Compounds) regime using five liquid culture media under both static and shaking conditions were investigated for their chemical and bioactivity profiles. All extracts showed strong anti-quorum sensing activity, and the majority of the Penicillium extracts displayed antimicrobial or anti-biofilm activity against Gram-negative environmental marine and human pathogens. HPLC-DAD-MS-based rapid metabolome analyses of the extracts indicated the high influence of culture conditions on the secondary metabolite (SM) profiles. Among 69 compounds detected in all Penicillium sp. extracts, 46 were successfully dereplicated. Analysis of SM relatedness in culture conditions by Hierarchical Cluster Analysis (HCA) revealed generally low similarity and showed a strong effect of medium selection on chemical profiles of Penicillium sp. This is the first study assessing both the metabolite and bioactivity profile of the fungi associated with Baltic eelgrass Z. marina.
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12
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Hong Y, Wu J, Guan F, Yue W, Long A. Nitrogen removal in the sediments of the Pearl River Estuary, China: Evidence from the distribution and forms of nitrogen in the sediment cores. MARINE POLLUTION BULLETIN 2019; 138:115-124. [PMID: 30660252 DOI: 10.1016/j.marpolbul.2018.11.040] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 11/07/2018] [Accepted: 11/16/2018] [Indexed: 06/09/2023]
Abstract
In this study, the spatial distribution and forms of nitrogen in sediment cores collected from the Pearl River Estuary were analyzed. Exchangeable nitrogen (Nex) comprised only a small proportion of total nitrogen (Ntot), with a mean of 3.54% in the sediment cores. NH4+ was the main form of Nex. No obvious change was observed in the vertical content of fixed ammonia (Nfix) in the sediments, and the mean Nfix in all five sediment cores was 141.23 mg·kg-1. The organic nitrogen (Norg), strongly related to organic carbon (Corg), was the main form in Ntot. The dissolved inorganic nitrogen in sediment pore water was much lower than that in estuarine water and no significant variation was observed from upstream to downstream. Our results indicated that most nitrogen deposited on surface sediments from overlying water was rapidly removed by a series of microbial processes, reducing the extent of nitrogen returning to overlying waters.
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Affiliation(s)
- Yiguo Hong
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China.
| | - Jiapeng Wu
- State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Fengjie Guan
- School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, PR China
| | - Weizhong Yue
- State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Aimin Long
- State Key Laboratory of Tropical Oceanography (LTO), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
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Fraser MW, Gleeson DB, Grierson PF, Laverock B, Kendrick GA. Metagenomic Evidence of Microbial Community Responsiveness to Phosphorus and Salinity Gradients in Seagrass Sediments. Front Microbiol 2018; 9:1703. [PMID: 30105009 PMCID: PMC6077243 DOI: 10.3389/fmicb.2018.01703] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/09/2018] [Indexed: 12/17/2022] Open
Abstract
Sediment microorganisms can have profound influence on productivity and functioning of marine ecosystems through their critical roles in regulating biogeochemical processes. However, the identity of sediment microorganisms that mediate organic matter turnover and nutrient cycling in seagrass sediments is only poorly understood. Here, we used metagenomic sequencing to investigate shifts in the structure and functioning of the microbial community of seagrass sediments across a salinity and phosphorus (P) availability gradient in Shark Bay, WA, Australia. This iconic ecosystem is oligotrophic and hypersaline with abundant seagrass meadows that directly contribute Shark Bay's status as a World Heritage Site. We show that sediment phosphonate metabolism genes as well as enzyme activities increase in hypersaline conditions with lower soluble reactive phosphate in the water column. Given that sediment organic P content is also highest where P concentrations in the water column are low, we suggest that microbial processing of organic P can contribute to the P requirements of seagrasses at particularly oligotrophic sites. Seagrass meadows are often highly productive in oligotrophic waters, and our findings suggest that an increase in the functional capacity of microbial communities in seagrass sediments to break down organic P may contribute to the high productivity of seagrass meadows under oligotrophic conditions. When compared to soil and sediment metagenomes from other aquatic and terrestrial ecosystems, we also show microbial communities in seagrass sediments have a disproportionately high abundance of putative phosphorus and sulfur metabolism genes, which may have played an important evolutionary role in allowing these angiosperms to recolonize the marine environment and prosper under oligotrophic conditions.
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Affiliation(s)
- Matthew W. Fraser
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- Oceans Institute, The University of Western Australia, Crawley, WA, Australia
| | - Deirdre B. Gleeson
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, Australia
| | - Pauline F. Grierson
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
| | - Bonnie Laverock
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- Oceans Institute, The University of Western Australia, Crawley, WA, Australia
- School of Science, Auckland University of Technology, Auckland, New Zealand
| | - Gary A. Kendrick
- School of Biological Sciences, The University of Western Australia, Crawley, WA, Australia
- Oceans Institute, The University of Western Australia, Crawley, WA, Australia
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