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Liébana R, Modin O, Persson F, Hermansson M, Wilén BM. Resistance of aerobic granular sludge microbiomes to periodic loss of biomass. Biofilm 2023; 6:100145. [PMID: 37575957 PMCID: PMC10415711 DOI: 10.1016/j.bioflm.2023.100145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/07/2023] [Accepted: 07/26/2023] [Indexed: 08/15/2023] Open
Abstract
Granular sludge is a biofilm process used for wastewater treatment which is currently being implemented worldwide. It is important to understand how disturbances affect the microbial community and performance of reactors. Here, two acetate-fed replicate reactors were inoculated with acclimatized sludge and the reactor performance, and the granular sludge microbial community succession were studied for 149 days. During this time, the microbial community was challenged by periodically removing half of the reactor biomass, subsequently increasing the food-to-microorganism (F/M) ratio. Diversity analysis together with null models show that overall, the microbial communities were resistant to the disturbances, observing some minor effects on polyphosphate-accumulating and denitrifying microbial communities and their associated reactor functions. Community turnover was driven by drift and random granule loss, and stochasticity was the governing ecological process for community assembly. These results evidence the aerobic granular sludge process as a robust system for wastewater treatment.
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Affiliation(s)
- Raquel Liébana
- Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
- AZTI, Marine Research Division, Basque Research Technology Alliance (BRTA), Txatxarramendi Ugartea z/g, 48395, Sukarrieta, Bizkaia, Spain
| | - Oskar Modin
- Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
| | - Frank Persson
- Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
| | - Malte Hermansson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9E, SE-413 90, Gothenburg, Sweden
| | - Britt-Marie Wilén
- Division of Water Environment Technology, Department of Architecture and Civil Engineering, Chalmers University of Technology, Sven Hultins gata 6, SE 412 96, Gothenburg, Sweden
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2
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Hou X, Zhu Y, Wu L, Wang J, Yan W, Gao S, Wang Y, Ma Y, Wang Y, Peng Z, Tao Y, Tang Q, Yang J, Xiao L. The investigation of the physiochemical factors and bacterial communities indicates a low-toxic infectious risk of the Qiujiang River in Shanghai, China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:69135-69149. [PMID: 37131005 DOI: 10.1007/s11356-023-27144-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 04/17/2023] [Indexed: 05/04/2023]
Abstract
The overall water quality of urban rivers is closely related to the community structure and the physiochemical factors in them. In this study, the bacterial communities and physiochemical factors of the Qiujiang River, an important urban river in Shanghai, were explored. Water samples were collected from nine sites of the Qiujiang River on November 16, 2020. The water quality and bacterial diversity were studied through physicochemical detection, microbial culture and identification, luminescence bacteria method, and 16S rRNA Illumina MiSeq high-throughput sequencing technology. The water pollution of the Qiujiang River was quite serious with three water quality evaluation indexes, including Cd2+, Pb2+, and NH4+-N, exceeding the Class V standard set by the Environmental Quality Standards for Surface Water (China, GB3838-2002), while the luminescent bacteria test indicated low toxicity of nine sampling sites. Through 16S rRNA sequencing, a total of 45 phyla, 124 classes, and 963 genera were identified, in which Proteobacteria, Gammaproteobacteria, and Limnohabitans were the most abundant phylum, class, and genus, respectively. The Spearman correlation heatmap and redundancy analysis showed that the bacterial communities in the Qiujiang River were correlated with pH; the concentrations of K+, and NH4+-N, and the Limnohabitans were significantly correlated with the concentrations of K+, and NH4+-N in the Zhongyuan Road bridge segment. In addition, opportunistic pathogens Enterobacter cloacae complex and Klebsiella pneumoniae in the samples collected in the Zhongyuan Road bridge segment and Huangpu River segment, respectively, were successfully cultured. The Qiujiang River was a heavily polluted urban river. The bacterial community structure and diversity were greatly affected by the physiochemical factors of the Qiujiang River, and it displayed low toxicity while a relatively high infectious risk of intestinal and lung infectious diseases.
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Affiliation(s)
- Xiaochuan Hou
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China
| | - Yina Zhu
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China
| | - Ling Wu
- Medical College of Yangzhou University, Yangzhou, 225001, China
| | - Jie Wang
- Administration Office for Undergraduates, Naval Medical University, Shanghai, 200433, China
| | - Wei Yan
- Naval Medical Center of PLA, Naval Medical University, Shanghai, 200052, China
| | - Songyu Gao
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China
| | - Yi Wang
- College of Traditional Chinese Medicine, Jilin Agricultural University, Changchun, 130118, China
| | - Yushi Ma
- Administration Office for Undergraduates, Naval Medical University, Shanghai, 200433, China
| | - Yongfang Wang
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China
| | - Zhaoyun Peng
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China
| | - Ye Tao
- Administration Office for Undergraduates, Naval Medical University, Shanghai, 200433, China
| | - Qinglong Tang
- Central Medical District of Chinese, PLA General Hospital, Beijing, 100120, China
| | - Jishun Yang
- Naval Medical Center of PLA, Naval Medical University, Shanghai, 200052, China
| | - Liang Xiao
- Faculty of Naval Medicine, Naval Medical University, Shanghai, 200433, China.
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3
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Liang QY, Zhang JY, Ning D, Yu WX, Chen GJ, Tao X, Zhou J, Du ZJ, Mu DS. Niche Modification by Sulfate-Reducing Bacteria Drives Microbial Community Assembly in Anoxic Marine Sediments. mBio 2023; 14:e0353522. [PMID: 36988509 PMCID: PMC10128000 DOI: 10.1128/mbio.03535-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/27/2023] [Indexed: 03/30/2023] Open
Abstract
Sulfate-reducing bacteria (SRB) are essential functional microbial taxa for degrading organic matter (OM) in anoxic marine environments. However, there are little experimental data regarding how SRB regulates microbial communities. Here, we applied a top-down microbial community management approach by inhibiting SRB to elucidate their contributions to the microbial community during OM degradation. Based on the highly replicated microcosms (n = 20) of five different incubation stages, we found that many microbial community properties were influenced after inhibiting SRB, including the composition, structure, network, and community assembly processes. We also found a strong coexistence pattern between SRB and other abundant phylogenetic lineages via positive frequency-dependent selection. The relative abundances of the families Synergistaceae, Peptostreptococcaceae, Dethiosulfatibacteraceae, Prolixibacteraceae, Marinilabiliaceae, and Marinifilaceae were simultaneously suppressed after inhibiting SRB during OM degradation. A close association between SRB and the order Marinilabiliales among coexisting taxa was most prominent. They contributed to preserved modules during network successions, were keystone nodes mediating the networked community, and contributed to homogeneous ecological selection. The molybdate tolerance test of the isolated strains of Marinilabiliales showed that inhibited SRB (not the inhibitor of SRB itself) triggered a decrease in the relative abundance of Marinilabiliales. We also found that inhibiting SRB resulted in reduced pH, which is unsuitable for the growth of most Marinilabiliales strains, while the addition of pH buffer (HEPES) in SRB-inhibited treatment microcosms restored the pH and the relative abundances of these bacteria. These data supported that SRB could modify niches to affect species coexistence. IMPORTANCE Our model offers insight into the ecological properties of SRB and identifies a previously undocumented dimension of OM degradation. This targeted inhibition approach could provide a novel framework for illustrating how functional microbial taxa associate the composition and structure of the microbial community, molecular ecological network, and community assembly processes. These findings emphasize the importance of SRB during OM degradation. Our results proved the feasibility of the proposed study framework, inhibiting functional taxa at the community level, for illustrating when and to what extent functional taxa can contribute to ecosystem services.
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Affiliation(s)
- Qi-Yun Liang
- Marine College, Shandong University, Weihai, People’s Republic of China
| | - Jin-Yu Zhang
- Marine College, Shandong University, Weihai, People’s Republic of China
| | - Daliang Ning
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Wen-Xing Yu
- Marine College, Shandong University, Weihai, People’s Republic of China
| | - Guan-Jun Chen
- Marine College, Shandong University, Weihai, People’s Republic of China
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Xuanyu Tao
- Institute for Environmental Genomics, University of Oklahoma, Norman, Oklahoma, USA
| | - Jizhong Zhou
- 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
| | - Zong-Jun Du
- Marine College, Shandong University, Weihai, People’s Republic of China
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
| | - Da-Shuai Mu
- Marine College, Shandong University, Weihai, People’s Republic of China
- State Key Laboratory of Microbial Technology, Institute of Microbial Technology, Shandong University, Qingdao, China
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4
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Liu H, Li FY, Liu J, Shi C, Tang K, Yang Q, Liu Y, Fu Q, Gao X, Wang N, Guo W. The reciprocal changes in dominant species with complete metabolic functions explain the decoupling phenomenon of microbial taxonomic and functional composition in a grassland. Front Microbiol 2023; 14:1113157. [PMID: 37007478 PMCID: PMC10060659 DOI: 10.3389/fmicb.2023.1113157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 02/22/2023] [Indexed: 03/18/2023] Open
Abstract
The decoupling of microbial functional and taxonomic components refers to the phenomenon that a drastic change in microbial taxonomic composition leads to no or only a gentle change in functional composition. Although many studies have identified this phenomenon, the mechanisms underlying it are still unclear. Here we demonstrate, using metagenomics data from a steppe grassland soil under different grazing and phosphorus addition treatments, that there is no “decoupling” in the variation of taxonomic and metabolic functional composition of the microbial community within functional groups at species level. In contrast, the high consistency and complementarity between the abundance and functional gene diversity of two dominant species made metabolic functions unaffected by grazing and phosphorus addition. This complementarity between the two dominant species shapes a bistability pattern that differs from functional redundancy in that only two species cannot form observable redundancy in a large microbial community. In other words, the “monopoly” of metabolic functions by the two most abundant species leads to the disappearance of functional redundancy. Our findings imply that for soil microbial communities, the impact of species identity on metabolic functions is much greater than that of species diversity, and it is more important to monitor the dynamics of key dominant microorganisms for accurately predicting the changes in the metabolic functions of the ecosystems.
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Affiliation(s)
- Huaiqiang Liu
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Frank Yonghong Li
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
- Collaborative Innovation Center for Grassland Ecological Security, Ministry of Education of China, Hohhot, China
- *Correspondence: Frank Yonghong Li,
| | - Jiayue Liu
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Chunjun Shi
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Kuanyan Tang
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Qianhui Yang
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Yu Liu
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Qiang Fu
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Xiaotian Gao
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Ning Wang
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
| | - Wei Guo
- Ministry of Education Key Laboratory of Ecology and Resource Use on the Mongolian Plateau and Inner Mongolia Key Laboratory of Grassland Ecology, School of Ecology and Environment, Inner Mongolia University, Hohhot, China
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5
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Bacteriomes in lesions of pulmonary tuberculosis and its association with status of Mycobacterium tuberculosis excretion. BMC Microbiol 2022; 22:280. [PMID: 36418957 PMCID: PMC9686068 DOI: 10.1186/s12866-022-02698-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 11/09/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Bacteria in lung play an important role in sustaining lung health. Understanding the characteristics of bacteriomes in lesions of pulmonary tuberculosis (TB) patients, who excrete Mycobacterium tuberculosis (MTB), is important for TB prevention and effective treatment. METHODS: In this study, bacteriomes in lesions from TB patients excreting bacteria (TB-E) and those from TB patients not excreting bacteria (TB-NE) with matched normal lung tissues (NT) were compared by 16S rRNA sequencing. Bacterial MetaCyc functions in TB lesions were also predicted by PICRUSt2 tool. RESULTS Alpha diversity of bacteria, including Chao 1 and Shannon indexes, for TB-E was significantly higher than those in TB-NE and NT; while for TB-NE group, Chao 1 index was higher than that in NT group. Predominant phyla in TB lesions and NT were Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes, but analysis of similarity (ANOSIM, p < 0.001) revealed significantly different bacterial compositions among TB-E, TB-NE and NT samples. As for bacteriomes in TB lesions, a strong association (ANOSIM, p < 0.001) was observed with the status of MTB excretion. Indicator genera identified in TB-E and TB-NE demonstrated distinctive micro-ecological environments of TB lesions from patients with different clinical manifestations. Co-occurrence analysis revealed a densely-linked bacterial community in TB-NE compared to that in TB-E. MetaCyc functions responsible for menaquinone synthesis and chorismate metabolism that could potentially impact the persistent-state and nutrient metabolism of MTB were enriched in TB-E samples. While in TB-NE samples, enrichment of bacterial MetaCyc function responsible for heme b synthesis might contribute to TB pathology through ferroptosis. CONCLUSION Bacteriomes and their MetaCyc functions in TB lesions are elucidated, and they are associated with status of MTB excretion among pulmonary TB patients. These results serve as a basis for designing novel strategies for preventing and treating pulmonary TB disease.
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6
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Caracciolo M, Rigaut-Jalabert F, Romac S, Mahé F, Forsans S, Gac JP, Arsenieff L, Manno M, Chaffron S, Cariou T, Hoebeke M, Bozec Y, Goberville E, Le Gall F, Guilloux L, Baudoux AC, de Vargas C, Not F, Thiébaut E, Henry N, Simon N. Seasonal dynamics of marine protist communities in tidally mixed coastal waters. Mol Ecol 2022; 31:3761-3783. [PMID: 35593305 PMCID: PMC9543310 DOI: 10.1111/mec.16539] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 12/29/2021] [Accepted: 04/19/2022] [Indexed: 12/01/2022]
Abstract
Major seasonal community reorganizations and associated biomass variations are landmarks of plankton ecology. However, the processes of plankton community turnover rates have not been fully elucidated so far. Here, we analyse patterns of planktonic protist community succession in temperate latitudes, based on quantitative taxonomic data from both microscopy counts (cells >10 μm) and ribosomal DNA metabarcoding (size fraction >3 μm, 18S rRNA gene) from plankton samples collected bimonthly over 8 years (2009–2016) at the SOMLIT‐Astan station (Roscoff, Western English Channel). Based on morphology, diatoms were clearly the dominating group all year round and over the study period. Metabarcoding uncovered a wider diversity spectrum and revealed the prevalence of Dinophyceae and diatoms but also of Cryptophyta, Chlorophyta, Cercozoa, Syndiniales and Ciliophora in terms of read counts and or richness. The use of morphological and molecular analyses in combination allowed improving the taxonomic resolution and to identify the sequence of the dominant species and OTUs (18S V4 rDNA‐derived taxa) that drive annual plankton successions. We detected that some of these dominant OTUs were benthic as a result of the intense tidal mixing typical of the French coasts in the English Channel. Our analysis of the temporal structure of community changes point to a strong seasonality and resilience. The temporal structure of environmental variables (especially Photosynthetic Active Radiation, temperature and macronutrients) and temporal structures generated by species life cycles and or species interactions, are key drivers of the observed cyclic annual plankton turnover.
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Affiliation(s)
| | | | | | | | | | | | - Laure Arsenieff
- Faculty of Biology, Technion - Israel Institute of Technology, Haifa 3200003, Israel
| | | | - Samuel Chaffron
- Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, 75016, Paris, France.,Laboratoire des Sciences du Numérique de Nantes (LS2N), CNRS, UMR6004, Université de Nantes, Ecole Centrale de Nantes, 44322, Nantes, France
| | - Thierry Cariou
- Institut de recherche pour le développement (IRD), Délégation Régionale Ouest, IMAGO, Plouzané, France
| | - Mark Hoebeke
- CNRS, Sorbonne Université, FR 2424, ABiMS Platform, Station Biologique de Roscoff, 29680, Roscoff, France
| | | | - Eric Goberville
- Unité biologie des organismes et écosystèmes aquatiques (BOREA), Muséum National D'Histoire Naturelle, Sorbonne Université, Université de Caen Normandie, Université des Antilles, CNRS, IRD, CP53, 61 rue Buffon 75005, Paris, France
| | | | - Loïc Guilloux
- Sorbonne Université, Roscoff, France.,Mediterranean Institute of Oceanography (MIO), Campus de Luminy case 901, 163 Av. de Luminy, 13288 Marseille cedex 9, France
| | | | - Colomban de Vargas
- Sorbonne Université, Roscoff, France.,Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, 75016, Paris, France
| | | | - Eric Thiébaut
- Sorbonne Université, Roscoff, France.,Sorbonne Université, CNRS, OSU STAMAR, UMS2017, 4 Place Jussieu, 75252 Paris cedex 05, France
| | - Nicolas Henry
- Sorbonne Université, Roscoff, France.,Research Federation for the study of Global Ocean Systems Ecology and Evolution, FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, 75016, Paris, France.,CNRS, Sorbonne Université, FR 2424, ABiMS Platform, Station Biologique de Roscoff, 29680, Roscoff, France
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7
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Metagenomic Sequencing Reveals that the Assembly of Functional Genes and Taxa Varied Highly and Lacked Redundancy in the Earthworm Gut Compared with Soil under Vanadium Stress. mSystems 2022; 7:e0125321. [PMID: 35089099 PMCID: PMC8725585 DOI: 10.1128/msystems.01253-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Exploring the ecological mechanism of microbial community assembly in soil and the earthworm gut in a vanadium polluted environment could help us understand the effects of vanadium stress on microbial diversity maintenance and function, as well as the mechanism of microbial mitigation of vanadium stress. Combining metagenomic sequencing and abundance distribution models, we explored the assembly of earthworm intestinal bacteria and native soil bacteria after 21 days of earthworm exposure to a gradient level of vanadate (0 to 300 mg kg−1) in soil. Stochastic processes dominated the assembly of both genes and taxa in earthworm gut and soil. Both the composition of taxa and functional genes in earthworm gut varied highly with the vanadium concentration, while in soil, only the taxa changed significantly, whereas the functional genes were relatively stable. The functional redundancy in soil, but not in the earthworm gut, was confirmed by a Mantel test and analysis of similarities (ANOSIM) test. In addition, vanadium detoxifying gene (VDG)-carrying taxa were more diverse but less abundant in soil than in the worm gut; and VDGs were more abundant in soil than in the worm gut. Their wider niche breadth indicated that VDG-carrying taxa were generalists in soil, in contrast to their role in the worm gut. These results suggested that earthworm intestinal and soil microbes adopted different strategies to counteract vanadium stress. The results provide new insights into the effects of soil vanadium stress on the assembly of earthworm gut and soil microbiota from both bacterial taxa and genetic function perspectives. IMPORTANCE Metagenomic sequencing revealed the variation of functional genes in the microbial community in soil and earthworm gut with increasing vanadium concentrations, which provided a new insight to explore the effect of vanadium stress on microbial community assembly from the perspective of functional genes. Our results reinforced the view that functional genes and taxa do not appear to have a simple corresponding relationship. Taxa are more sensitive compared with functional genes, suggesting the existence of bacterial functional redundancy in soil, but not in the earthworm gut. These observations indicate different assembly patterns of earthworm intestinal and soil bacteria under vanadium stress. Thus, it is important and necessary to include genetic functions to comprehensively understand microbial community assembly.
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8
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Mechanisms Driving Microbial Community Composition in Anaerobic Co-Digestion of Waste-Activated Sewage Sludge. Bioengineering (Basel) 2021; 8:bioengineering8120197. [PMID: 34940350 PMCID: PMC8699016 DOI: 10.3390/bioengineering8120197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
Anaerobic co-digestion (Co-AD) is used to increase the effectiveness of anaerobic digestion (AD) using local “wastes”, adding economic and environmental benefits. Since system stability is of existential importance for the operation of wastewater treatment plants, thorough testing of potential co-substrates and their effects on the respective community and system performance is crucial for understanding and utilizing Co-AD to its best capacity. Food waste (FW) and canola lecithin (CL) were tested in mesophilic, lab-scale, semi-continuous reactors over a duration of 120 days with stepwise increased substrate addition. Key performance indicators (biogas, total/volatile solids, fatty acids) were monitored and combined with 16S-rRNA amplicon sequencing to assess the impact of co-substrate addition on reactor performance and microbial community composition (MCC). Additionally, the latter was then compared with natural shifts occurring in the wastewater treatment plant (WWTP, source) at the same time. An almost linear increase in biogas production with both co-substrates at an approximate 1:1 ratio with the organic loading rate (OLR) was observed. The MCCs in both experiments were mostly stable, but also prone to drift over time. The FW experiment MCC more closely resembled the original WWTP community and the observed shifts indicated high levels of functional redundancy. Exclusive to the CL co-substrate, a clear selection for a few operational taxonomic units (OTUs) was observed. There was little evidence for a persistent invasion and establishment of microorganisms from typical primary substrates into the stable resident community of the reactors, which is in line with earlier findings that suggested that the inoculum and history mostly define the MCC. However, external factors may still tip the scales in favor of a few r-strategists (e.g., Prolixibacter) in an environment that otherwise favors K-strategists, which may in fact also be recruited from the primary substrate (Trichococcus). In our study, specialization and diversity loss were also observed in response to the addition of the highly specialized CL, which in turn, may have adverse effects on the system’s stability and reduced resilience and recovery.
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9
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Cai W, Zhao M, Kong J, Riggio S, Finnigan T, Stuckey D, Guo M. Linkage of community composition and function over short response time in anaerobic digestion systems with food fermentation wastewater. iScience 2021; 24:102958. [PMID: 34466784 PMCID: PMC8384924 DOI: 10.1016/j.isci.2021.102958] [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: 02/11/2021] [Revised: 07/11/2021] [Accepted: 08/03/2021] [Indexed: 01/28/2023] Open
Abstract
We investigated the short-term dynamics of microbial composition and function in bioreactors with inocula collected from full-scale and laboratory-based anaerobic digestion (AD) systems. The Bray-Curtis dissimilarity of both inocula was approximately 10% of the predicted Kyoto Encyclopedia of Genes and Genomes pathway and 40% of the taxonomic composition and yet resulted in a similar performance in methane production, implying that the variation of community composition may be decoupled from performance. However, the significant correlation of volatile fatty acids with taxonomic variation suggested that the pathways of AD could be different because of the varying genus. The predicted function of the significantly varying genus was mostly related to fermentation, which strengthened the conclusion that most microbial variation occurred within the fermentative species and led to alternative routes to result in similar methane production in methanogenic bioreactors. This finding sheds some light on the understanding of AD community regulation, which depends on the aims to recover intermediates or methane.
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Affiliation(s)
- Weiwei Cai
- School of Civil Engineering, Beijing Jiaotong University, Beijing 100044, China.,Department of Engineering, King's College London, London WC2R 2LS, UK
| | - Mingxing Zhao
- Department of Civil and Environmental Engineering, Imperial College London, London SW7 2AZ, UK.,Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK.,School of Environment and Civil Engineering, Jiangnan University, Wuxi, Jiangsu Province, China
| | - Jianyao Kong
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Silvio Riggio
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Tim Finnigan
- Quorn Foods, Station Road, Stokesley, North Yorkshire TS9 7AB, UK
| | - David Stuckey
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Miao Guo
- Department of Engineering, King's College London, London WC2R 2LS, UK.,Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
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10
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Wang C, Liu S, Wang P, Chen J, Wang X, Yuan Q, Ma J. How sediment bacterial community shifts along the urban river located in mining city. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:42300-42312. [PMID: 33811632 DOI: 10.1007/s11356-020-12031-0] [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] [Received: 10/04/2020] [Accepted: 12/08/2020] [Indexed: 06/12/2023]
Abstract
Bacterial communities play critical roles in biogeochemical cycles and serve as sensitive indicators of environmental fluctuation. However, the influence of mineral resource exploitation on shaping the bacterial communities in the urban river is still ambiguous. In this study, high-throughput sequencing was used to determine the spatial distribution of the sediment bacterial communities along an urban river in the famous mining city Panzhihua of China. The results showed that mineral resource exploitation had a significant impact on the urban river bacterial community structure but not on the bacterial ecological functions. Distinct families of bacteria often associated with nutrients (i.e., Comamonadaceae and Sphingomonadaceae) and metal contaminants (i.e., Rhodobacteraceae) were more predominant in the residential and mining area, respectively. Relative to dispersal dynamics, environmentally induced species sorting may primarily influence bacterial community structure. Heavy metals and sediment physicochemical properties had both similar and significant influence on shaping bacterial community structure. Among heavy metals, essential metal elements explained more rates of bacterial variation than toxic metals at moderate contaminant levels. Moreover, the bacteria with multiple metal resistances identified in culture-dependent experiments were probably not suitable for indicating heavy metal contamination in field research. Thus, several sensitive bacterial genera such as Rhodobacter, Hylemonella, and Dechloromonas were identified as potential bioindicators to monitor metals (iron and titanium) and nutrients (phosphorus and organic carbon) in the river ecosystem of the Panzhihua region. Together, these results profiled the coupling effect of urbanization and mineral resource utilization on shaping sediment bacterial communities in urban rivers.
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Affiliation(s)
- Chao Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
| | - Sheng Liu
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
| | - Peifang Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China.
| | - Juan Chen
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
| | - Xun Wang
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
| | - Qiusheng Yuan
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
| | - Jingjie Ma
- Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1 Xikang Road, Nanjing, 210098, China
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11
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Diego D, Hannisdal B, Dahle H. On how the power supply shapes microbial survival. Math Biosci 2021; 338:108615. [PMID: 33857526 DOI: 10.1016/j.mbs.2021.108615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 03/29/2021] [Accepted: 04/04/2021] [Indexed: 10/21/2022]
Abstract
Understanding how environmental factors affect microbial survival is an important open problem in microbial ecology. Patterns of microbial community structure have been characterized across a wide range of different environmental settings, but the mechanisms generating these patterns remain poorly understood. Here, we use mathematical modelling to investigate fundamental connections between chemical power supply to a system and patterns of microbial survival. We reveal a complex set of interdependences between power supply and distributions of survival probability across microbial habitats, in a case without interspecific resource competition. We also find that different properties determining power supply, such as substrate fluxes and Gibbs energies of reactions, affect microbial survival in fundamentally different ways. Moreover, we show how simple connections between power supply and growth can give rise to complex patterns of microbial survival across physicochemical gradients, such as pH gradients. Our findings show the importance of taking energy fluxes into account in order to reveal fundamental connections between microbial survival and environmental conditions, and to obtain a better understanding of microbial population dynamics in natural environments.
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Affiliation(s)
- David Diego
- Department of Earth Science, University of Bergen, Allégaten, NO-5007 Bergen, Norway; K.G. Jebsen Centre for Deep Sea Research, Allégaten, NO-5007 Bergen, Norway.
| | - Bjarte Hannisdal
- Department of Earth Science, University of Bergen, Allégaten, NO-5007 Bergen, Norway; K.G. Jebsen Centre for Deep Sea Research, Allégaten, NO-5007 Bergen, Norway
| | - Håkon Dahle
- K.G. Jebsen Centre for Deep Sea Research, Allégaten, NO-5007 Bergen, Norway; Department of Biological Sciences, University of Bergen, Thormøhlens gate 53A, NO-5006 Bergen, Norway; Computational Biology Unit, Department of Informatics, University of Bergen, N-5020 Bergen, Norway
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12
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Miao Y, Heintz MB, Bell CH, Johnson NW, Polasko AL, Favero D, Mahendra S. Profiling microbial community structures and functions in bioremediation strategies for treating 1,4-dioxane-contaminated groundwater. JOURNAL OF HAZARDOUS MATERIALS 2021; 408:124457. [PMID: 33189472 DOI: 10.1016/j.jhazmat.2020.124457] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/28/2020] [Accepted: 10/30/2020] [Indexed: 06/11/2023]
Abstract
Microbial community compositions and functional profiles were analyzed in microcosms established using aquifer materials from a former automobile factory site, where 1,4-dioxane was identified as the primary contaminant of concern. Propane or oxygen biostimulation resulted in limited 1,4-dioxane degradation, which was markedly enhanced with the addition of nutrients, resulting in abundant Mycobacterium and Methyloversatilis taxa and high expressions of propane monooxygenase gene, prmA. In bioaugmented treatments, Pseudonocardia dioxanivorans CB1190 or Rhodococcus ruber ENV425 strains dominated immediately after augmentation and degraded 1,4-dioxane rapidly which was consistent with increased representation of xenobiotic and lipid metabolism-related functions. Although the bioaugmented microbes decreased due to insufficient growth substrates and microbial competition, they did continue to degrade 1,4-dioxane, presumably by indigenous propanotrophic and heterotrophic bacteria, inducing similar community structures across bioaugmentation conditions. In various treatments, functional redundancy acted as buffer capacity to ensure a stable microbiome, drove the restoration of the structure and microbial functions to original levels, and induced the decoupling between basic metabolic functions and taxonomy. The results of this study provided valuable information for design and decision-making for ex-situ bioreactors and in-situ bioremediation applications. A metagenomics-based understanding of the treatment process will enable efficient and accurate adjustments when encountering unexpected issues in bioremediation.
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Affiliation(s)
- Yu Miao
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States
| | - Monica B Heintz
- Arcadis North America, Highlands Ranch, CO 80129, United States
| | | | - Nicholas W Johnson
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States
| | - Alexandra LaPat Polasko
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States
| | - David Favero
- Revitalizing Auto Communities Environmental Response (RACER) Trust, Detroit, MI 48226, United States
| | - Shaily Mahendra
- Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, United States.
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13
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Nielsen SN, Müller F, Marques JC, Bastianoni S, Jørgensen SE. Thermodynamics in Ecology-An Introductory Review. ENTROPY 2020; 22:e22080820. [PMID: 33286591 PMCID: PMC7517404 DOI: 10.3390/e22080820] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/17/2020] [Accepted: 07/17/2020] [Indexed: 02/07/2023]
Abstract
How to predict the evolution of ecosystems is one of the numerous questions asked of ecologists by managers and politicians. To answer this we will need to give a scientific definition to concepts like sustainability, integrity, resilience and ecosystem health. This is not an easy task, as modern ecosystem theory exemplifies. Ecosystems show a high degree of complexity, based upon a high number of compartments, interactions and regulations. The last two decades have offered proposals for interpretation of ecosystems within a framework of thermodynamics. The entrance point of such an understanding of ecosystems was delivered more than 50 years ago through Schrödinger’s and Prigogine’s interpretations of living systems as “negentropy feeders” and “dissipative structures”, respectively. Combining these views from the far from equilibrium thermodynamics to traditional classical thermodynamics, and ecology is obviously not going to happen without problems. There seems little reason to doubt that far from equilibrium systems, such as organisms or ecosystems, also have to obey fundamental physical principles such as mass conservation, first and second law of thermodynamics. Both have been applied in ecology since the 1950s and lately the concepts of exergy and entropy have been introduced. Exergy has recently been proposed, from several directions, as a useful indicator of the state, structure and function of the ecosystem. The proposals take two main directions, one concerned with the exergy stored in the ecosystem, the other with the exergy degraded and entropy formation. The implementation of exergy in ecology has often been explained as a translation of the Darwinian principle of “survival of the fittest” into thermodynamics. The fittest ecosystem, being the one able to use and store fluxes of energy and materials in the most efficient manner. The major problem in the transfer to ecology is that thermodynamic properties can only be calculated and not measured. Most of the supportive evidence comes from aquatic ecosystems. Results show that natural and culturally induced changes in the ecosystems, are accompanied by a variations in exergy. In brief, ecological succession is followed by an increase of exergy. This paper aims to describe the state-of-the-art in implementation of thermodynamics into ecology. This includes a brief outline of the history and the derivation of the thermodynamic functions used today. Examples of applications and results achieved up to now are given, and the importance to management laid out. Some suggestions for essential future research agendas of issues that needs resolution are given.
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Affiliation(s)
- Søren Nors Nielsen
- Department of Chemistry and Bioscience, Section for Sustainable Biotechnology, Aalborg University, A.C. Meyers Vænge 15, DK-2450 Copenhagen SV, Denmark
- Correspondence:
| | - Felix Müller
- Department of Ecosystem Management, Institute for Natural Resource Conservation, Christian-Albrechts-Universität zu Kiel, Olshausenstrasse 75, D-24118 Kiel, Germany;
| | - Joao Carlos Marques
- MARE—Marine and Environmental Sciences Centre, Department of Life Sciences, University of Coimbra, 3000-456 Coimbra, Portugal;
| | - Simone Bastianoni
- Department of Earth, Environmental and Physical Sciences, University of Siena, Pian dei Mantellini 44, 53100 Siena, Italy;
| | - Sven Erik Jørgensen
- Department of General Chemistry, Environmental Chemistry Section, Pharmaceutical Faculty, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen Ø, Denmark
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14
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Purkamo L, Kietäväinen R, Nuppunen-Puputti M, Bomberg M, Cousins C. Ultradeep Microbial Communities at 4.4 km within Crystalline Bedrock: Implications for Habitability in a Planetary Context. Life (Basel) 2020; 10:E2. [PMID: 31947979 PMCID: PMC7175195 DOI: 10.3390/life10010002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 12/31/2019] [Accepted: 01/01/2020] [Indexed: 01/06/2023] Open
Abstract
The deep bedrock surroundings are an analog for extraterrestrial habitats for life. In this study, we investigated microbial life within anoxic ultradeep boreholes in Precambrian bedrock, including the adaptation to environmental conditions and lifestyle of these organisms. Samples were collected from Pyhäsalmi mine environment in central Finland and from geothermal drilling wells in Otaniemi, Espoo, in southern Finland. Microbial communities inhabiting the up to 4.4 km deep bedrock were characterized with phylogenetic marker gene (16S rRNA genes and fungal ITS region) amplicon and DNA and cDNA metagenomic sequencing. Functional marker genes (dsrB, mcrA, narG) were quantified with qPCR. Results showed that although crystalline bedrock provides very limited substrates for life, the microbial communities are diverse. Gammaproteobacterial phylotypes were most dominant in both studied sites. Alkanindiges -affiliating OTU was dominating in Pyhäsalmi fluids, while different depths of Otaniemi samples were dominated by Pseudomonas. One of the most common OTUs detected from Otaniemi could only be classified to phylum level, highlighting the uncharacterized nature of the deep biosphere in bedrock. Chemoheterotrophy, fermentation and nitrogen cycling are potentially significant metabolisms in these ultradeep environments. To conclude, this study provides information on microbial ecology of low biomass, carbon-depleted and energy-deprived deep subsurface environment. This information is useful in the prospect of finding life in other planetary bodies.
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Affiliation(s)
- Lotta Purkamo
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 9AL, UK
- Geological Survey of Finland, 02151 Espoo, Finland
| | - Riikka Kietäväinen
- Geological Survey of Finland, 02151 Espoo, Finland
- Department of Geosciences and Geography, University of Helsinki, 00014 Helsinki, Finland
| | | | - Malin Bomberg
- VTT Technical Research Centre of Finland, 02044 VTT, Finland
| | - Claire Cousins
- School of Earth and Environmental Sciences, University of St Andrews, St Andrews KY16 9AL, UK
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15
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Braz GHR, Fernandez-Gonzalez N, Lema JM, Carballa M. Organic overloading affects the microbial interactions during anaerobic digestion in sewage sludge reactors. CHEMOSPHERE 2019; 222:323-332. [PMID: 30708166 DOI: 10.1016/j.chemosphere.2019.01.124] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 11/21/2018] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
There is still a lack of information about microbial interactions of anaerobic digestion microbiome during process disturbance which limits our ability to predict the mechanisms that drive community dynamics on these events. This paper aims to determine how an organic overloading affects these interactions and to characterize in detail the microbiome structure and diversity in sewage sludge anaerobic reactors during an acidosis event. Two identical sewage sludge anaerobic reactors were subjected to an organic loading shock by adding glycerol waste. As consequence, volatile fatty acids accumulated after only 24 h (up to 2.5 g/L) while Bacteroidales and Methanomicrobiales became displaced by Firmicutes and Methanosaeta sp, showing that reactor acidosis can occur without an immediate decline of this methanogen. Network analysis revealed 9 clusters of co-occurring microorganisms with different behaviors during overloading. At first, Veillonellaceae family, the main glycerol degrading, associated with Candidatus Cloacimonetes, volatile fatty acids fermenters, increased their relative abundance in detriment of the syntrophic bacteria; although as conditions become more acidic, these groups were displaced by other fermenters like Porphyromonadaceae and Chitinophagaceae. Eventually, the methanogenesis failed 72 h after organic overloading, when pH reached values lower than 6. Overall, our results showed a succession of functionally redundant microorganisms, most likely because of niche specialization during organic overloading. The detailed temporal analysis elucidated the processes governing the dynamics anaerobic digestion microbiome, a knowledge required to develop anaerobic digestion management strategies based on its microbiome during process disturbances.
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Affiliation(s)
- Guilherme H R Braz
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Constantino Candeira s/n, 15782 Santiago de Compostela, Galicia, Spain.
| | - Nuria Fernandez-Gonzalez
- Department of Chemical Engineering and Environmental Technology, School of Industrial Engineerings, Venue Dr. Mergelina, C/ Dr. Mergelina, s/n, Valladolid 47011, Spain; Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Constantino Candeira s/n, 15782 Santiago de Compostela, Galicia, Spain.
| | - Juan M Lema
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Constantino Candeira s/n, 15782 Santiago de Compostela, Galicia, Spain.
| | - Marta Carballa
- Department of Chemical Engineering, Institute of Technology, Universidade de Santiago de Compostela, Constantino Candeira s/n, 15782 Santiago de Compostela, Galicia, Spain.
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16
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Peces M, Astals S, Jensen PD, Clarke WP. Deterministic mechanisms define the long-term anaerobic digestion microbiome and its functionality regardless of the initial microbial community. WATER RESEARCH 2018; 141:366-376. [PMID: 29807319 DOI: 10.1016/j.watres.2018.05.028] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/16/2018] [Accepted: 05/16/2018] [Indexed: 06/08/2023]
Abstract
The impact of the starting inoculum on long-term anaerobic digestion performance, process functionality and microbial community composition remains unclear. To understand the impact of starting inoculum, active microbial communities from four different full-scale anaerobic digesters were each used to inoculate four continuous lab-scale anaerobic digesters, which were operated identically for 295 days. Digesters were operated at 15 days solid retention time, an organic loading rate of 1 g COD Lr-1 d-1 (75:25 - cellulose:casein) and 37 °C. Results showed that long-term process performance, metabolic rates (hydrolytic, acetogenic, and methanogenic) and microbial community are independent of the inoculum source. Digesters process performance converged after 80 days, while metabolic rates and microbial communities converged after 120-145 days. The convergence of the different microbial communities towards a core-community proves that the deterministic factors (process operational conditions) were a stronger driver than the initial microbial community composition. Indeed, the core-community represented 72% of the relative abundance among the four digesters. Moreover, a number of positive correlations were observed between higher metabolic rates and the relative abundance of specific microbial groups. These correlations showed that both substrate consumers and suppliers trigger higher metabolic rates, expanding the knowledge of the nexus between microorganisms and functionality. Overall, these results support that deterministic factors control microbial communities in bioreactors independently of the inoculum source. Hence, it seems plausible that a desired microbial composition and functionality can be achieved by tuning process operational conditions.
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Affiliation(s)
- M Peces
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia Campus, 4072, QLD, Australia.
| | - S Astals
- Advanced Water Management Centre, The University of Queensland, St. Lucia Campus, 4072, QLD, Australia
| | - P D Jensen
- Advanced Water Management Centre, The University of Queensland, St. Lucia Campus, 4072, QLD, Australia
| | - W P Clarke
- Centre for Solid Waste Bioprocessing, Schools of Civil and Chemical Engineering, The University of Queensland, St. Lucia Campus, 4072, QLD, Australia
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17
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Microbial Community Cohesion Mediates Community Turnover in Unperturbed Aquifers. mSystems 2018; 3:mSystems00066-18. [PMID: 29984314 PMCID: PMC6030547 DOI: 10.1128/msystems.00066-18] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 06/12/2018] [Indexed: 01/10/2023] Open
Abstract
Many microbial ecology studies have examined community structuring processes in dynamic or perturbed situations, while stable environments have been investigated to a lesser extent. Researchers have predicted that environmental communities never truly reach a steady state but rather exist in states of constant flux due to internal, rather than external, dynamics. The research presented here utilized a combined null model approach to examine the deterministic and stochastic processes responsible for observed community differences in unperturbed, groundwater ecosystems. Additionally, internal dynamics were investigated by relating a recently published measure of community complexity (cohesion) to ecological structuring processes. The data presented here suggest that communities that are more cohesive, and therefore more complex, are more likely affected by homogenizing selection, while less-complex communities are more susceptible to dispersal. By understanding the relationship between internal dynamics and community structuring processes, insight about microbial population development in natural systems can be obtained. Microbial ecological processes are frequently studied in the presence of perturbations rather than in undisturbed environments, despite the relatively stable conditions dominating many microbial habitats. To examine processes influencing microbial community structuring in the absence of strong external perturbations, three unperturbed aquifers in Ohio (Greene, Licking, and Athens) were sampled over 2 years and analyzed using geochemical measurements, 16S rRNA gene sequencing, and ecological modeling. Redox conditions ranging from highly reducing to more oxidizing distinguished aquifer geochemistry across the three locations. Distinct microbial communities were present in each aquifer, and overall community structure was related to geochemistry, although community composition was more similar between the Athens and Licking locations. The ecological processes acting upon microbial assemblages within aquifers were varied; geochemical changes affected the Athens location, while time or some unknown factor affected Greene County. Stochastic processes, however, dominated the Licking aquifer, suggesting a decoupling between environmental fluctuations and community development. Although physicochemical differences might be expected to drive variable selection, dispersal limitation (inability to mix) explained differences between Athens and Licking. Finally, community complexity as measured by “cohesion” indicated that less-interconnected communities experienced higher turnover and were more likely to be affected by stochastic processes. Conversely, more-interconnected communities experienced lower turnover and susceptibility to homogenizing selection. Based upon these data, we support the hypothesis that unperturbed environments house dynamic microbial communities due to external and internal forces. IMPORTANCE Many microbial ecology studies have examined community structuring processes in dynamic or perturbed situations, while stable environments have been investigated to a lesser extent. Researchers have predicted that environmental communities never truly reach a steady state but rather exist in states of constant flux due to internal, rather than external, dynamics. The research presented here utilized a combined null model approach to examine the deterministic and stochastic processes responsible for observed community differences in unperturbed, groundwater ecosystems. Additionally, internal dynamics were investigated by relating a recently published measure of community complexity (cohesion) to ecological structuring processes. The data presented here suggest that communities that are more cohesive, and therefore more complex, are more likely affected by homogenizing selection, while less-complex communities are more susceptible to dispersal. By understanding the relationship between internal dynamics and community structuring processes, insight about microbial population development in natural systems can be obtained.
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18
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Function and functional redundancy in microbial systems. Nat Ecol Evol 2018; 2:936-943. [PMID: 29662222 DOI: 10.1038/s41559-018-0519-1] [Citation(s) in RCA: 614] [Impact Index Per Article: 102.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 02/26/2018] [Indexed: 11/08/2022]
Abstract
Microbial communities often exhibit incredible taxonomic diversity, raising questions regarding the mechanisms enabling species coexistence and the role of this diversity in community functioning. On the one hand, many coexisting but taxonomically distinct microorganisms can encode the same energy-yielding metabolic functions, and this functional redundancy contrasts with the expectation that species should occupy distinct metabolic niches. On the other hand, the identity of taxa encoding each function can vary substantially across space or time with little effect on the function, and this taxonomic variability is frequently thought to result from ecological drift between equivalent organisms. Here, we synthesize the powerful paradigm emerging from these two patterns, connecting the roles of function, functional redundancy and taxonomy in microbial systems. We conclude that both patterns are unlikely to be the result of ecological drift, but are inevitable emergent properties of open microbial systems resulting mainly from biotic interactions and environmental and spatial processes.
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19
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Louca S, Doebeli M. Taxonomic variability and functional stability in microbial communities infected by phages. Environ Microbiol 2017; 19:3863-3878. [PMID: 28371143 DOI: 10.1111/1462-2920.13743] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 03/16/2017] [Accepted: 03/24/2017] [Indexed: 11/28/2022]
Abstract
Microbial communities can display large variation in taxonomic composition, yet this variation can coincide with stable metabolic functional structure and performance. The mechanisms driving the taxonomic variation within functional groups remain largely unknown. Biotic interactions, such as predation by phages, have been suggested as potential cause of taxonomic turnover, but the conditions for this scenario have not been rigorously examined. Further, it is unknown how predation by phages affects community function, and how these effects are modulated by functional redundancy in the communities. Here, we address these questions using a model for a methanogenic microbial community that includes several interacting metabolic functional groups. Each functional group comprises multiple competing clades, and each clade is attacked by a specialist lytic phage. Our model predicts that phages induce intense taxonomic turnover, resembling the variability observed in previous experiments. The functional structure and performance of the community are also disturbed by phage predation, but they become more stable as the functional redundancy in the community increases. The extent of this stabilization depends on the particular functions considered. Our model suggests mechanisms by which functional redundancy stabilizes community function and supports the interpretation that biotic interactions promote taxonomic turnover within microbial functional groups.
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Affiliation(s)
- Stilianos Louca
- Biodiversity Research Centre, University of British Columbia, Canada.,Department of Zoology, University of British Columbia, Canada
| | - Michael Doebeli
- Biodiversity Research Centre, University of British Columbia, Canada.,Department of Zoology, University of British Columbia, Canada.,Department of Mathematics, University of British Columbia, Canada
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