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Qin Y, Wu L, Zhang Q, Wen C, Van Nostrand JD, Ning D, Raskin L, Pinto A, Zhou J. Effects of error, chimera, bias, and GC content on the accuracy of amplicon sequencing. mSystems 2023; 8:e0102523. [PMID: 38038441 PMCID: PMC10734440 DOI: 10.1128/msystems.01025-23] [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: 10/11/2023] [Accepted: 10/17/2023] [Indexed: 12/02/2023] Open
Abstract
IMPORTANCE Amplicon sequencing of targeted genes is the predominant approach to estimate the membership and structure of microbial communities. However, accurate reconstruction of community composition is difficult due to sequencing errors, and other methodological biases and effective approaches to overcome these challenges are essential. Using a mock community of 33 phylogenetically diverse strains, this study evaluated the effect of GC content on sequencing results and tested different approaches to improve overall sequencing accuracy while characterizing the pros and cons of popular amplicon sequence data processing approaches. The sequencing results from this study can serve as a benchmarking data set for future algorithmic improvements. Furthermore, the new insights on sequencing error, chimera formation, and GC bias from this study will help enhance the quality of amplicon sequencing studies and support the development of new data analysis approaches.
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Affiliation(s)
- Yujia Qin
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Liyou Wu
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Qiuting Zhang
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Chongqin Wen
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
- Fisheries College, Guangdong Ocean University, Zhanjiang, Guangdong, China
| | - Joy D. Van Nostrand
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Daliang Ning
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Lutgarde Raskin
- Department of Civil and Environmental Engineering, University of Michigan, Ann Arbor, Michigan, USA
| | - Ameet Pinto
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Jizhong Zhou
- Department of Microbiology and Plant Biology, Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
- State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing, China
- Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
- School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, Oklahoma, USA
- School of Computer Science, University of Oklahoma, Norman, Oklahoma, USA
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Araujo ASF, Jia X, Miranda ARL, Pereira APDA, Melo VMM, Rocha SMB, Costa RM, Saraiva TCDS, Mendes LW, Salles JF. Changes in the bacterial rare biosphere after permanent application of composted tannery sludge in a tropical soil. CHEMOSPHERE 2023; 313:137487. [PMID: 36521745 DOI: 10.1016/j.chemosphere.2022.137487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 11/21/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
Composted tannery sludge (CTS) promotes shifts in soil chemical properties, affecting microbial communities. Although the effect of CTS application on the bacterial community has been studied, it is unclear whether this impact discriminates between the dominant and rare species. This present study investigated how the dominant and rare bacterial communities respond over time to different concentrations of CTS application (0, 2.5, 5, 10, and 20 tons/ha) for 180 days. The richness of operational taxonomic units (OTU) was 30-fold higher in the rare than in the dominant biosphere. While some phyla shifted their relative abundance differently in the dominant and rare biosphere, some genera increased their relative abundance under higher CTS concentrations, such as Nocardioides (∼100%), Rubrobacter (∼300%), and Nordella (∼400%). Undominated processes largely governed the dominant biosphere (76.97%), followed by homogeneous (12.51%) and variable (8.03%) selection, and to a lesser extent, the dispersal limitation (2.48%). The rare biosphere was driven by the CTS application as evidenced by the exclusively homogeneous selection (100%). This study showed that the rare biosphere was more sensitive to changes in soil chemical parameters due to CTS application, which evidences the importance explore this portion of the bacterial community for its biotechnological use in contaminated soils.
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Affiliation(s)
| | - Xiu Jia
- Microbial Ecology Cluster, Genomics Research in Ecology and Evolution in Nature (GREEN), Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen 9747AG, the Netherlands
| | | | | | | | | | | | | | - Lucas William Mendes
- Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba, SP Brazil
| | - Joana Falcão Salles
- Microbial Ecology Cluster, Genomics Research in Ecology and Evolution in Nature (GREEN), Groningen Institute for Evolutionary Life Sciences (GELIFES), University of Groningen, Groningen 9747AG, the Netherlands
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Yu Z, Pei Y, Zhao S, Kakade A, Khan A, Sharma M, Zain H, Feng P, Ji J, Zhou T, Wang H, Wu J, Li X. Metatranscriptomic analysis reveals active microbes and genes responded to short-term Cr(VI) stress. ECOTOXICOLOGY (LONDON, ENGLAND) 2021; 30:1527-1537. [PMID: 33123966 DOI: 10.1007/s10646-020-02290-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/10/2020] [Indexed: 06/11/2023]
Abstract
Heavy metals have been severely polluting the environment. However, the response mechanism of microbial communities to short-term heavy metals stress remains unclear. In this study, metagenomics (MG) and metatranscriptomics (MT) was performed to observe the microbial response to short-term Cr(VI) stress. MG data showed that 99.1% of species were similar in the control and Cr(VI) treated groups. However, MT data demonstrated that 83% of the microbes were active in which 58.7% increased, while the relative abundance of 41.3% decreased after short-term Cr(VI) incubation. The MT results also revealed 9% of microbes were dormant in samples. Genes associated with oxidative stress, Cr(VI) transport, resistance, and reduction, as well as genes with unknown functions were 2-10 times upregulated after Cr(VI) treatment. To further confirm the function of unknown genes, two genes (314 and 494) were selected to detect the Cr(VI) resistance and reduction ability. The results showed that these genes significantly increased the Cr(VI) remediation ability of Escherichia coli. MT results also revealed an increase in the expression of some rare genera (at least two times) after Cr(VI) treatment, indicating these rare species played a crucial role in microbial response to short-term Cr(VI) stress. In summary, MT is an efficient way to understand the role of active and dormant microbes in specific environmental conditions.
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Affiliation(s)
- Zhengsheng Yu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Yaxin Pei
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Shuai Zhao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Apurva Kakade
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Aman Khan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Monika Sharma
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Hajira Zain
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Pengya Feng
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Jing Ji
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Tuoyu Zhou
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Haoyang Wang
- McMaster University, 1280 Main Street West, Hamilton, ON, Canada
| | - Jingyuan Wu
- The First Clinical Medical College, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China.
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environment Pollution, School of Life Science, Lanzhou University, Tianshuinanlu #222, Lanzhou, 730000, Gansu, PR China.
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Mena C, Balbín R, Reglero P, Martín M, Santiago R, Sintes E. Dynamic prokaryotic communities in the dark western Mediterranean Sea. Sci Rep 2021; 11:17859. [PMID: 34504142 PMCID: PMC8429679 DOI: 10.1038/s41598-021-96992-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/17/2021] [Indexed: 02/07/2023] Open
Abstract
Dark ocean microbial dynamics are fundamental to understand ecosystem metabolism and ocean biogeochemical processes. Yet, the ecological response of deep ocean communities to environmental perturbations remains largely unknown. Temporal and spatial dynamics of the meso- and bathypelagic prokaryotic communities were assessed throughout a 2-year seasonal sampling across the western Mediterranean Sea. A common pattern of prokaryotic communities' depth stratification was observed across the different regions and throughout the seasons. However, sporadic and drastic alterations of the community composition and diversity occurred either at specific water masses or throughout the aphotic zone and at a basin scale. Environmental changes resulted in a major increase in the abundance of rare or low abundant phylotypes and a profound change of the community composition. Our study evidences the temporal dynamism of dark ocean prokaryotic communities, exhibiting long periods of stability but also drastic changes, with implications in community metabolism and carbon fluxes. Taken together, the results highlight the importance of monitoring the temporal patterns of dark ocean prokaryotic communities.
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Affiliation(s)
- Catalina Mena
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain.
- IFREMER - Centre Bretagne Z.I., Technopôle Brest-Iroise Pointe du Diable BP70, 29280Plouzané, France.
| | - Rosa Balbín
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain
| | - Patricia Reglero
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain
| | - Melissa Martín
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain
| | - Rocío Santiago
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain
| | - Eva Sintes
- Instituto Español de Oceanografía, Centre Oceanogràfic de Les Balears, Ecosystem Oceanography Group (GRECO), Moll de Ponent s/n 07015, Palma, Spain
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5
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Cai X, Mao Y, Xu J, Tian L, Wang Y, Iqbal W, Yang B, Liu C, Zhao X, Wang Y. Characterizing community dynamics and exploring bacterial assemblages in two activated sludge systems. Appl Microbiol Biotechnol 2020; 104:1795-1808. [PMID: 31900552 DOI: 10.1007/s00253-019-10279-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 11/19/2019] [Accepted: 11/26/2019] [Indexed: 01/12/2023]
Abstract
Bacterial communities in the activated sludge (AS) determine the wastewater treatment performance in the municipal wastewater treatment plants (WWTPs). Aiming at identifying the affecting factors and the variation patterns of the bacterial assemblages in AS, a 2-year time-series AS samples were collected from two separated WWTPs and metagenomic sequencing was conducted. Obvious seasonal shift and succession of the bacterial community were observed in both WWTPs on the genus and species levels, especially for the persistent taxa, implying that temperature was a decisive factor for maintaining bacterial assemblage patterns in long-term period. Taxa abundance distribution (TAD) concerning occurrence frequency and average abundance were found fitting for exponential formulations, and the approximately equal total abundance of persistent taxa suggested that stable and high abundance (~ 90%) of core functional bacterial groups would help to maintain wastewater treatment performance. Drastic changes of environmental factors were found causing temporally significant bacterial structure variation, while the innate correlations between bacterial species could recover the community gradually and maintain relative stability of the AS system. Delayed correlations between environmental factors and abundant (persistent or intermittent) bacterial species were observed widely, while synchronous biotic interactions were identified more frequently. Besides, bacterial species with similar functions were prone to cluster together and shared the same seasonal variation pattern, implicating that the cooperation of functional correlated taxa played the most dominant role in shaping the bacterial assemblages. Furthermore, rare bacterial groups were to be explored for removing emerging pollutants with lower concentrations. The results of this study would assist dealing with operational defect and optimize the treatment system in WWTPs.
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Affiliation(s)
- Xunchao Cai
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Yanping Mao
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China.
| | - Jianyu Xu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Li Tian
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Yicheng Wang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Waheed Iqbal
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Bo Yang
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Changkun Liu
- College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, Guangdong, China
| | - Xu Zhao
- Key Laboratory of Drinking Water Science and Technology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Yuexing Wang
- Shenzhen Shenshui Ecological & Environmental Technology Co., Ltd, Shenzhen, 518000, Guangdong, China
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6
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Yamamoto K, Hackley KC, Kelly WR, Panno SV, Sekiguchi Y, Sanford RA, Liu WT, Kamagata Y, Tamaki H. Diversity and geochemical community assembly processes of the living rare biosphere in a sand-and-gravel aquifer ecosystem in the Midwestern United States. Sci Rep 2019; 9:13484. [PMID: 31530884 PMCID: PMC6748922 DOI: 10.1038/s41598-019-49996-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 09/04/2019] [Indexed: 01/24/2023] Open
Abstract
Natural microbial communities consist of a limited number of abundant species and an extraordinarily diverse population of rare species referred to as the rare biosphere. Recent studies have revealed that the rare biosphere is not merely an inactive dormant population but may play substantial functional roles in the ecosystem. However, structure, activity and community assembly processes of the rare biosphere are poorly understood. In this study, we evaluated the present and living microbial community structures including rare populations in an aquifer ecosystem, the Mahomet Aquifer, USA, by both 16S rDNA and rRNA amplicon deep sequencing. The 13 groundwater samples formed three distinct groups based on the “entire” community structure, and the same grouping was obtained when focusing on the “rare” subcommunities (<0.1% of total abundance), while the “abundant” subcommunities (>1.0%) gave a different grouping. In the correlation analyses, the observed grouping pattern is associated with several geochemical factors, and structures of not only the entire community but also the rare subcommunity are correlated with geochemical profiles in the aquifer ecosystem. Our findings first indicate that the living rare biosphere in the aquifer system has the metabolic potential to adapt to local geochemical factors which dictate the community assembly processes.
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Affiliation(s)
- Kyosuke Yamamoto
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan.,Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | | | - Walton R Kelly
- Groundwater Science Section, Illinois State Water Survey, Prairie Research Institute, University of Illinois at Urbana-Champaign (UIUC), Champaign, IL, USA
| | - Samuel V Panno
- Illinois State Geological Survey, Prairie Research Institute, UIUC, Champaign, IL, USA
| | - Yuji Sekiguchi
- Biomedical Research Institute, AIST, Tsukuba, Ibaraki, Japan
| | | | - Wen-Tso Liu
- Department of Civil and Environmental Engineering, UIUC, Urbana, IL, USA
| | - Yoichi Kamagata
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Hideyuki Tamaki
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan. .,Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan. .,Department of Civil and Environmental Engineering, UIUC, Urbana, IL, USA. .,Biotechnology Research Center, The University of Tokyo, Tokyo, Japan.
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7
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Jiang XT, Ye L, Ju F, Wang YL, Zhang T. Toward an Intensive Longitudinal Understanding of Activated Sludge Bacterial Assembly and Dynamics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:8224-8232. [PMID: 29943968 DOI: 10.1021/acs.est.7b05579] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Temporal microbial community studies have broadened our knowledge of the dynamics and correlations among microbes in both natural and artificial engineering systems. Using activated sludge as a model system, we utilized the intensive longitudinal sampling method to identify overlooked diversity and the hidden dynamics of microbes, detect cross-associations among microbes after detrending, and reveal the central microbial dynamics during sludge bulking and foaming. We discovered that the accumulative alpha diversity in activated sludge sampled daily over 392 days could be as high as 14 000 OTUs, and that the bacterial community dynamics followed a gradual succession, drifting away from the initial observed day and displaying a significant time-dependent trend. Cross-associations among bacteria were modulated after removing potential spurious correlations based on autocorrelation in microbial time series. Moreover, clusters of bacteria displaying rapid turnover were discovered during the beginning, ongoing, and fading of sludge bulking and foaming, and their physicochemical parameters are resolved. These identified groups of bacteria and their related environmental factors could potentially supply clues to form hypotheses for treating operational problems, such as sludge bulking and foaming.
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Affiliation(s)
- Xiao-Tao Jiang
- Environmental Biotechnology Lab , The University of Hong Kong , Pokfulam , Hong Kong , SAR China
| | - Lin Ye
- Environmental Biotechnology Lab , The University of Hong Kong , Pokfulam , Hong Kong , SAR China
| | - Feng Ju
- Environmental Biotechnology Lab , The University of Hong Kong , Pokfulam , Hong Kong , SAR China
| | - Yu-Lin Wang
- Environmental Biotechnology Lab , The University of Hong Kong , Pokfulam , Hong Kong , SAR China
| | - Tong Zhang
- Environmental Biotechnology Lab , The University of Hong Kong , Pokfulam , Hong Kong , SAR China
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8
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Guillemette R, Kaneko R, Blanton J, Tan J, Witt M, Hamilton S, Allen EE, Medina M, Hamasaki K, Koch BP, Azam F. Bacterioplankton drawdown of coral mass-spawned organic matter. ISME JOURNAL 2018; 12:2238-2251. [PMID: 29884827 PMCID: PMC6092384 DOI: 10.1038/s41396-018-0197-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 03/23/2018] [Accepted: 04/12/2018] [Indexed: 11/09/2022]
Abstract
Coral reef ecosystems are highly sensitive to microbial activities that result from dissolved organic matter (DOM) enrichment of their surrounding seawater. However, the response to particulate organic matter (POM) enrichment is less studied. In a microcosm experiment, we tested the response of bacterioplankton to a pulse of POM from the mass-spawning of Orbicella franksi coral off the Caribbean coast of Panama. Particulate organic carbon (POC), a proxy measurement for POM, increased by 40-fold in seawater samples collected during spawning; 68% degraded within 66 h. The elevation of multiple hydrolases presumably solubilized the spawn-derived POM into DOM. A carbon budget constructed for the 275 µM of degraded POC showed negligible change to the concentration of dissolved organic carbon (DOC), indicating that the DOM was readily utilized. Fourier transform ion cyclotron resonance mass spectrometry shows that the DOM pool became enriched with heteroatom-containing molecules, a trend that suggests microbial alteration of organic matter. Our sensitivity analysis demonstrates that bacterial carbon demand could have accounted for a large proportion of the POC degradation. Further, using bromodeoxyuridine immunocapture in combination with 454 pyrosequencing of the 16S ribosomal RNA gene, we surmise that actively growing bacterial groups were the primary degraders. We conclude that coral gametes are highly labile to bacteria and that such large capacity for bacterial degradation and alteration of organic matter has implications for coral reef health and coastal marine biogeochemistry.
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Affiliation(s)
- Ryan Guillemette
- Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA.
| | - Ryo Kaneko
- National Institute of Polar Research (NIPR), Tokyo, Japan
| | - Jessica Blanton
- Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA
| | - Jasmine Tan
- Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA
| | | | | | - Eric E Allen
- Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA
| | - Mónica Medina
- Pennsylvania State University, University Park, PA, USA
| | - Koji Hamasaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Tokyo, Japan
| | - Boris P Koch
- Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
| | - Farooq Azam
- Scripps Institution of Oceanography, UC San Diego, San Diego, CA, USA
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9
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Mixing it up in the ocean carbon cycle and the removal of refractory dissolved organic carbon. Sci Rep 2018; 8:2542. [PMID: 29416076 PMCID: PMC5803198 DOI: 10.1038/s41598-018-20857-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Accepted: 01/25/2018] [Indexed: 11/08/2022] Open
Abstract
A large quantity of reduced carbon is sequestered in the ocean as refractory dissolved molecules that persist through several circuits of global overturning circulation. Key aspects of the cycling of refractory dissolved organic carbon (DOC) remain unknown, making it challenging to predict how this large carbon reservoir will respond to climate change. Herein we investigate mechanisms that remove refractory DOC using bioassay experiments with DOC isolated from surface, mesopelagic and deep waters of the Atlantic Ocean. The isolated DOC was refractory to degradation by native microbial communities, even at elevated concentrations. However, when the refractory DOC was introduced to a series of novel environmental conditions, including addition of a labile substrate, a microbial community from coastal waters and exposure to solar radiation, a substantial fraction (7–13%) was removed within 1.5 years. Our results suggest that while refractory molecules can persist in the ocean for millennia, removal is rapid when they encounter their fate. The observed and projected climate-induced slowdown of global overturning circulation could reduce the exposure of refractory molecules to disparate removal processes. Assuming a constant rate of production, the reservoir size of refractory DOC could increase as overturning circulation slows, providing a negative feedback to rising atmospheric CO2.
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10
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Singer E, Wagner M, Woyke T. Capturing the genetic makeup of the active microbiome in situ. THE ISME JOURNAL 2017; 11:1949-1963. [PMID: 28574490 PMCID: PMC5563950 DOI: 10.1038/ismej.2017.59] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/02/2017] [Accepted: 03/10/2017] [Indexed: 12/21/2022]
Abstract
More than any other technology, nucleic acid sequencing has enabled microbial ecology studies to be complemented with the data volumes necessary to capture the extent of microbial diversity and dynamics in a wide range of environments. In order to truly understand and predict environmental processes, however, the distinction between active, inactive and dead microbial cells is critical. Also, experimental designs need to be sensitive toward varying population complexity and activity, and temporal as well as spatial scales of process rates. There are a number of approaches, including single-cell techniques, which were designed to study in situ microbial activity and that have been successively coupled to nucleic acid sequencing. The exciting new discoveries regarding in situ microbial activity provide evidence that future microbial ecology studies will indispensably rely on techniques that specifically capture members of the microbiome active in the environment. Herein, we review those currently used activity-based approaches that can be directly linked to shotgun nucleic acid sequencing, evaluate their relevance to ecology studies, and discuss future directions.
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Affiliation(s)
- Esther Singer
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
| | - Michael Wagner
- University of Vienna, Department of Microbial Ecology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria
| | - Tanja Woyke
- US Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
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