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Khomyakova MA, Merkel AY, Novikov AA, Slobodkin AI. Peloplasma aerotolerans gen. nov., sp. nov., a Novel Anaerobic Free-Living Mollicute Isolated from a Terrestrial Mud Volcano. Life (Basel) 2024; 14:563. [PMID: 38792585 PMCID: PMC11122141 DOI: 10.3390/life14050563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
A novel aerotolerant anaerobic bacterium (strain M4AhT) was isolated from a terrestrial mud volcano (Taman Peninsula, Russia). Cells were small, cell-wall-less, non-motile cocci, 0.32-0.65 μm in diameter. The isolate was a mesophilic, neutrophilic chemoorganoheterotroph, growing on carbohydrates (D-glucose, D-trehalose, D-ribose, D-mannose, D-xylose, D-maltose, D-lactose, D-cellobiose, D-galactose, D-fructose, and D-sucrose), proteinaceous compounds (yeast extract, tryptone), and pyruvate. Strain M4AhT tolerated 2% oxygen in the gas phase, was catalase-positive, and showed sustainable growth under microaerobic conditions. The dominant cellular fatty acids of strain M4AhT were C16:0 and C18:0. The G+C content of the genomic DNA was 32.42%. The closest phylogenetic relative of strain M4AhT was Mariniplasma anaerobium from the family Acholeplasmataceae (order Acholeplasmatales, class Mollicutes). Based on the polyphasic characterization of the isolate, strain M4AhT is considered to represent a novel species of a new genus, for which the name Peloplasma aerotolerans gen. nov., sp. nov. is proposed. The type strain of Peloplasma aerotolerans is M4AhT (=DSM 112561T = VKM B-3485T = UQM 41475T). This is the first representative of the order Acholeplasmatales, isolated from a mud volcano.
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Affiliation(s)
- Maria A. Khomyakova
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Leninskiy Prospect, 33, bld. 2, 119071 Moscow, Russia
| | - Alexander Y. Merkel
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Leninskiy Prospect, 33, bld. 2, 119071 Moscow, Russia
| | - Andrei A. Novikov
- Department of Physical and Colloid Chemistry, Gubkin University, Leninskiy Prospect, 65/1, 119991 Moscow, Russia
| | - Alexander I. Slobodkin
- Winogradsky Institute of Microbiology, Research Center of Biotechnology of the Russian Academy of Sciences, Leninskiy Prospect, 33, bld. 2, 119071 Moscow, Russia
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Pei L, Song Y, Chen G, Mu L, Yan B, Zhou T. Enhancement of methane production from anaerobic digestion of Erigeron canadensis via O 2-nanobubble water supplementation. CHEMOSPHERE 2024; 354:141732. [PMID: 38499072 DOI: 10.1016/j.chemosphere.2024.141732] [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: 08/01/2023] [Revised: 11/30/2023] [Accepted: 03/14/2024] [Indexed: 03/20/2024]
Abstract
Malignant invasive Erigeron canadensis, as a typical lignocellulosic biomass, is a formidable challenge for sustainable and efficient resource utilization, however nanobubble water (NBW) coupled with anaerobic digestion furnishes a prospective strategy with superior environmental and economic effectiveness. In this study, influence mechanism of various O2-NBW addition times on methanogenic performance of E. canadensis during anaerobic digestion were performed to achieve the optimal pollution-free energy conversion. Results showed that supplementation of O2-NBW in digestion system could significantly enhance the methane production by 10.70-16.17%, while the maximum cumulative methane production reached 343.18 mL g-1 VS in the case of one-time O2-NBW addition on day 0. Furthermore, addition of O2-NBW was conducive to an increase of 2-90% in the activities of dehydrogenase, α-glucosidase and coenzyme F420. Simultaneously, both facultative bacteria and methanogenic archaea were enriched as well, further indicating that O2-NBW might be responsible for facilitating hydrolytic acidification and methanogenesis. Based on Kyoto Encyclopedia of Genes and Genomes (KEGG) cluster analysis, provision of O2-NBW enhanced the metabolism of carbohydrate and amino acid, translation as well as membrane transport of bacteria and archaea. This study might offer the theoretical guidance and novel insights for efficient recovery of energy from lignocellulosic biomass on account of O2-NBW adhibition in anaerobic digestion system, progressing tenor of carbon-neutral vision.
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Affiliation(s)
- Legeng Pei
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Yingjin Song
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; Double Carbon Research Institute, Tianjin, 300350, China.
| | - Guanyi Chen
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China; School of Mechanical Engineering, Tianjin University of Commerce, Tianjin, 300134, China; Double Carbon Research Institute, Tianjin, 300350, China
| | - Lan Mu
- School of Mechanical Engineering, Tianjin University of Commerce, Tianjin, 300134, China
| | - Beibei Yan
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
| | - Teng Zhou
- School of Environmental Science and Engineering, Tianjin University, Tianjin, 300072, China
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Cao F, Jin L, Gao Y, Ding Y, Wen H, Qian Z, Zhang C, Hong L, Yang H, Zhang J, Tong Z, Wang W, Chen X, Mao Z. Artificial-enzymes-armed Bifidobacterium longum probiotics for alleviating intestinal inflammation and microbiota dysbiosis. NATURE NANOTECHNOLOGY 2023; 18:617-627. [PMID: 36973397 DOI: 10.1038/s41565-023-01346-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Inflammatory bowel disease can be caused by the dysfunction of the intestinal mucosal barrier and dysregulation of gut microbiota. Traditional treatments use drugs to manage inflammation with possible probiotic therapy as an adjuvant. However, current standard practices often suffer from metabolic instability, limited targeting and result in unsatisfactory therapeutic outcomes. Here we report on artificial-enzyme-modified Bifidobacterium longum probiotics for reshaping a healthy immune system in inflammatory bowel disease. Probiotics can promote the targeting and retention of the biocompatible artificial enzymes to persistently scavenge elevated reactive oxygen species and alleviate inflammatory factors. The reduced inflammation caused by artificial enzymes improves bacterial viability to rapidly reshape the intestinal barrier functions and restore the gut microbiota. The therapeutic effects are demonstrated in murine and canine models and show superior outcomes to traditional clinical drugs.
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Affiliation(s)
- Fangfang Cao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and College of Design and Engineering, National University of Singapore, Singapore, Singapore
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Lulu Jin
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Yong Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Yuan Ding
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hongyang Wen
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Zhefeng Qian
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Chenyin Zhang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Liangjie Hong
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Huang Yang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Jiaojiao Zhang
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
| | - Zongrui Tong
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Weilin Wang
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
| | - Xiaoyuan Chen
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and College of Design and Engineering, National University of Singapore, Singapore, Singapore.
- Nanomedicine Translational Research Program, NUS Center for Nanomedicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Clinical Imaging Research Centre, Centre for Translational Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Singapore, Singapore.
| | - Zhengwei Mao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, China.
- Department of Hepatobiliary and Pancreatic Surgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
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Shi K, Cheng H, Cornell CR, Wu H, Gao S, Jiang J, Liu T, Wang A, Zhou J, Liang B. Micro-aeration assisted with electrogenic respiration enhanced the microbial catabolism and ammonification of aromatic amines in industrial wastewater. JOURNAL OF HAZARDOUS MATERIALS 2023; 448:130943. [PMID: 36860074 DOI: 10.1016/j.jhazmat.2023.130943] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 01/29/2023] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
Improvement of refractory nitrogen-containing organics biodegradation is crucial to meet discharged nitrogen standards and guarantee aquatic ecology safety. Although electrostimulation accelerates organic nitrogen pollutants amination, it remains uncertain how to strengthen ammonification of the amination products. This study demonstrated that ammonification was remarkably facilitated under micro-aerobic conditions through the degradation of aniline, an amination product of nitrobenzene, using an electrogenic respiration system. The microbial catabolism and ammonification were significantly enhanced by exposing the bioanode to air. Based on 16S rRNA gene sequencing and GeoChip analysis, our results indicated that aerobic aniline degraders and electroactive bacteria were enriched in suspension and inner electrode biofilm, respectively. The suspension community had a significantly higher relative abundance of catechol dioxygenase genes contributing to aerobic aniline biodegradation and reactive oxygen species (ROS) scavenger genes to protect from oxygen toxicity. The inner biofilm community contained obviously higher cytochrome c genes responsible for extracellular electron transfer. Additionally, network analysis indicated the aniline degraders were positively associated with electroactive bacteria and could be the potential hosts for genes encoding for dioxygenase and cytochrome, respectively. This study provides a feasible strategy to enhance nitrogen-containing organics ammonification and offers new insights into the microbial interaction mechanisms of micro-aeration assisted with electrogenic respiration.
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Affiliation(s)
- Ke Shi
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Haoyi Cheng
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Carolyn R Cornell
- Department of Civil and Environmental Engineering, Rice University, Houston, TX 77005, USA
| | - Haiwei Wu
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Shuhong Gao
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Jiandong Jiang
- Key Lab of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, 210095 Nanjing, China
| | - Tiejun Liu
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Aijie Wang
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China
| | - Jizhong Zhou
- Institute for Environmental Genomics and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA; School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK 73019, USA; School of Computer Science, University of Oklahoma, Norman, OK 73019, USA; Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Bin Liang
- State Key Laboratory of Urban Water Resource and Environment, Shenzhen Key Laboratory of Organic Pollution Prevention and Control, School of Civil & Environmental Engineering, Harbin Institute of Technology Shenzhen, Shenzhen 518055, China.
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Cao Q, Zhang W, Lian T, Wang S, Yin F, Zhou T, Wei X, Dong H. Revealing mechanism of micro-aeration for enhancing volatile fatty acids production from swine manure. BIORESOURCE TECHNOLOGY 2022; 365:128140. [PMID: 36252761 DOI: 10.1016/j.biortech.2022.128140] [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: 08/06/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Micro-aeration is considered a new strategy for improving volatile fatty acids (VFAs) production of agricultural waste. This study investigated the effect and mechanism of micro-aeration of air and oxygen (O2) on VFAs production from swine manure. The results showed that Air-micro-aeration had the most significant improvement effect, with the highest VFAs of 8.21 g/L, which was increased by 22.4%. Moreover, the mixing effects of different micro-aeration were limited, and the microbial communities significantly varied. Firmicutes and Bacteroidota were the dominant hydrolytic and acidogenic bacteria, and Air-micro-aeration preferentially promoted electron transfer activity and energy generation. Methanosarcina, Methanocorpusculum, and Methanobrevibacter can adapt to environmental changes according to their different oxygen tolerance, and the consumption and conversion of VFAs by methanogens were slow under Air-micro-aeration condition. This study revealed mechanism of micro-aeration for improving VFAs production from swine manure, providing a theoretical basis for micro-aeration regulation optimization.
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Affiliation(s)
- Qitao Cao
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Wanqin Zhang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tianjing Lian
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China; College of Natural Resources and Environment, Northwest A&F University, Yangling 712100, PR China
| | - Shunli Wang
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Fubin Yin
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Tanlong Zhou
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Xiaoman Wei
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China
| | - Hongmin Dong
- Institute of Environment and Sustainable Development in Agriculture, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
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Bryukhanov AL, Klimko AI, Netrusov AI. Antioxidant Properties of Lactic Acid Bacteria. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722601439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Li J, Ran X, Zhou M, Wang K, Wang H, Wang Y. Oxidative stress and antioxidant mechanisms of obligate anaerobes involved in biological waste treatment processes: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156454. [PMID: 35667421 DOI: 10.1016/j.scitotenv.2022.156454] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/23/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
In-depth understanding of the molecular mechanisms and physiological consequences of oxidative stress is still limited for anaerobes. Anaerobic biotechnology has become widely accepted by the wastewater/sludge industry as a better alternative to more conventional but costly aerobic processes. However, the functional anaerobic microorganisms used in anaerobic biotechnology are frequently hampered by reactive oxygen/nitrogen species (ROS/RNS)-mediated oxidative stress caused by exposure to stressful factors (e.g., oxygen and heavy metals), which negatively impact treatment performance. Thus, identifying stressful factors and understanding antioxidative defense mechanisms of functional obligate anaerobes are crucial for the optimization of anaerobic bioprocesses. Herein, we present a comprehensive overview of oxidative stress and antioxidant mechanisms of obligate anaerobes involved in anaerobic bioprocesses; as examples, we focus on anaerobic ammonium oxidation bacteria and methanogenic archaea. We summarize the primary stress factors in anaerobic bioprocesses and the cellular antioxidant defense systems of functional anaerobes, a consortia of enzymatic and nonenzymatic mechanisms. The dual role of ROS/RNS in cellular processes is elaborated; at low concentrations, they have vital cell signaling functions, but at high concentrations, they cause oxidative damage. Finally, we highlight gaps in knowledge and future work to uncover antioxidant and damage repair mechanisms in obligate anaerobes. This review provides in-depth insights and guidance for future research on oxidative stress of obligate anaerobes to boost the accurate regulation of anaerobic bioprocesses in challenging and changing operating conditions.
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Affiliation(s)
- Jia Li
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Xiaochuan Ran
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Mingda Zhou
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Kaichong Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
| | - Han Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China.
| | - Yayi Wang
- State Key Laboratory of Pollution Control and Resources Reuse, Shanghai Institute of Pollution Control and Ecological Security, Tongji University, Shanghai 200092, China
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Li JT, Jia P, Wang XJ, Ou SN, Yang TT, Feng SW, Lu JL, Fang Z, Liu J, Liao B, Shu WS, Liang JL. Metagenomic and metatranscriptomic insights into sulfate-reducing bacteria in a revegetated acidic mine wasteland. NPJ Biofilms Microbiomes 2022; 8:71. [PMID: 36068230 PMCID: PMC9448743 DOI: 10.1038/s41522-022-00333-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022] Open
Abstract
The widespread occurrence of sulfate-reducing microorganisms (SRMs) in temporarily oxic/hypoxic aquatic environments indicates an intriguing possibility that SRMs can prevail in constantly oxic/hypoxic terrestrial sulfate-rich environments. However, little attention has been given to this possibility, leading to an incomplete understanding of microorganisms driving the terrestrial part of the global sulfur (S) cycle. In this study, genome-centric metagenomics and metatranscriptomics were employed to explore the diversity, metabolic potential, and gene expression profile of SRMs in a revegetated acidic mine wasteland under constantly oxic/hypoxic conditions. We recovered 16 medium- to high-quality metagenome-assembled genomes (MAGs) containing reductive dsrAB. Among them, 12 and four MAGs belonged to Acidobacteria and Deltaproteobacteria, respectively, harboring three new SRM genera. Comparative genomic analysis based on seven high-quality MAGs (completeness >90% and contamination <10%; including six acidobacterial and one deltaproteobacterial) and genomes of three additional cultured model species showed that Acidobacteria-related SRMs had more genes encoding glycoside hydrolases, oxygen-tolerant hydrogenases, and cytochrome c oxidases than Deltaproteobacteria-related SRMs. The opposite pattern was observed for genes encoding superoxide reductases and thioredoxin peroxidases. Using VirSorter, viral genome sequences were found in five of the 16 MAGs and in all three cultured model species. These prophages encoded enzymes involved in glycoside hydrolysis and antioxidation in their hosts. Moreover, metatranscriptomic analysis revealed that 15 of the 16 SRMs reported here were active in situ. An acidobacterial MAG containing a prophage dominated the SRM transcripts, expressing a large number of genes involved in its response to oxidative stress and competition for organic matter.
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Affiliation(s)
- Jin-Tian Li
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China.,School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Pu Jia
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Xiao-Juan Wang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Shu-Ning Ou
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Tao-Tao Yang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Shi-Wei Feng
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Jing-Li Lu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Zhou Fang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Jun Liu
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Bin Liao
- School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, PR China
| | - Wen-Sheng Shu
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China
| | - Jie-Liang Liang
- Institute of Ecological Science, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Sciences, South China Normal University, Guangzhou, 510631, PR China.
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The Diverse Indigenous Bacterial Community in the Rudna Mine Does Not Cause Dissolution of Copper from Kupferschiefer in Oxic Conditions. MINERALS 2022. [DOI: 10.3390/min12030366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Blasting and fracking of rock in mines exposes fresh rock surfaces to the local water and microbial communities. This may lead to leaching of metals from the rock by chemical or biological means and can cause acidification of the water system in the mine, i.e., acid rock drainage (ARD). Failure to prevent leakage of metal contaminated mine water may be harmful for the environment, especially to the local groundwater. In the Rudna mine, Poland, an in situ bioleaching pilot test at approximately 1 km depth was performed in the H2020 BIOMOre project (Grant Agreement #642456). After the leaching stage, different methods for irreversible inhibition of acidophilic iron oxidizing microorganisms used for reoxidation of reduced iron in the leaching solution were tested and were shown to be effective. However, the potential of the natural mine water microbial communities to cause leaching of copper or acidification of the mine waters has not been tested. In this study, we set up a microcosm experiment simulating the exposure of freshly fractionated Kupferschiefer sandstone or black schist to two different chloride-rich water types in the Rudna mine. The pH of the microcosms water was measured over time. At the end of an 18-week incubation, the bacterial community was examined by high throughput sequencing and qPCR, and the presence of copper tolerant heterotrophic bacteria was tested by cultivation. The dissolution of copper into the chloride rich microcosm water was measured. The pH in the microcosms did not decrease over the time of incubation. The sandstone increased the number of bacteria in the microcosms with one or over two orders of magnitude compared to the original water. The bacterial communities in the two tested mine waters were diverse and similar despite the difference in salinity. The bacterial diversity was high but changed in the less saline water during the incubation. There was a high content of sulphate reducing bacteria in the original mine waters and in the microcosms, and their number increased during the incubation. No acidophilic iron oxidizers were detected, but in the microcosms containing the less saline water low numbers of Cu tolerant bacteria were detected. Copper to a concentration of up to 939 mg L−1 was leached from the rock also in the microbe-free negative controls, which was up to 2.4 times that leached in the biotic microcosms, indicating that the leaching was also abiotic, not only caused by bacteria.
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Piacentino D, Grant-Beurmann S, Vizioli C, Li X, Moore CF, Ruiz-Rodado V, Lee MR, Joseph PV, Fraser CM, Weerts EM, Leggio L. Gut microbiome and metabolome in a non-human primate model of chronic excessive alcohol drinking. Transl Psychiatry 2021; 11:609. [PMID: 34853299 PMCID: PMC8636625 DOI: 10.1038/s41398-021-01728-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 10/27/2021] [Accepted: 11/05/2021] [Indexed: 02/08/2023] Open
Abstract
A relationship between the gut microbiome and alcohol use disorder has been suggested. Excessive alcohol use produces changes in the fecal microbiome and metabolome in both rodents and humans. Yet, these changes can be observed only in a subgroup of the studied populations, and reversal does not always occur after abstinence. We aimed to analyze fecal microbial composition and function in a translationally relevant baboon model of chronic heavy drinking that also meets binge criteria (drinking too much, too fast, and too often), i.e., alcohol ~1 g/kg and blood alcohol levels (BALs) ≥ 0.08 g/dL in a 2-hour period, daily, for years. We compared three groups of male baboons (Papio anubis): L = Long-term alcohol drinking group (12.1 years); S = Short-term alcohol drinking group (2.7 years); and C = Control group, drinking a non-alcoholic reinforcer (Tang®) (8.2 years). Fecal collection took place during 3 days of Drinking (D), followed by a short period (3 days) of Abstinence (A). Fecal microbial alpha- and beta-diversity were significantly lower in L vs. S and C (p's < 0.05). Members of the commensal families Lachnospiraceae and Prevotellaceae showed a relative decrease, whereas the opportunistic pathogen Streptococcus genus showed a relative increase in L vs. S and C (p's < 0.05). Microbiota-related metabolites of aromatic amino acids, tricarboxylic acid cycle, and pentose increased in L vs. S and C (FDR-corrected p < 0.01), with the latter two suggesting high energy metabolism and enhanced glycolysis in the gut lumen in response to alcohol. Consistent with the long-term alcohol exposure, mucosal damage and oxidative stress markers (N-acetylated amino acids, 2-hydroxybutyrate, and metabolites of the methionine cycle) increased in L vs. S and C (FDR-corrected p < 0.01). Overall, S showed few differences vs. C, possibly due to the long-term, chronic alcohol exposure needed to alter the normal gut microbiota. In the three groups, the fecal microbiome barely differed between conditions D and A, whereas the metabolome shifted in the transition from condition D to A. In conclusion, changes in the fecal microbiome and metabolome occur after significant long-term excessive drinking and are only partially affected by acute forced abstinence from alcohol. These results provide novel information on the relationship between the fecal microbiome and metabolome in a controlled experimental setting and using a unique non-human primate model of chronic excessive alcohol drinking.
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Affiliation(s)
- Daria Piacentino
- grid.94365.3d0000 0001 2297 5165Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224 USA ,grid.94365.3d0000 0001 2297 5165Center on Compulsive Behaviors, National Institutes of Health, 10 Center Dr, Bethesda, MD 20892 USA
| | - Silvia Grant-Beurmann
- grid.411024.20000 0001 2175 4264Institute for Genome Sciences, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD USA
| | - Carlotta Vizioli
- grid.420085.b0000 0004 0481 4802Sensory Science and Metabolism Unit, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute of Nursing Research Division of Intramural Research, 10 Center Dr, Bethesda, MD 20892 USA
| | - Xiaobai Li
- grid.94365.3d0000 0001 2297 5165Biostatistics and Clinical Epidemiology Services, National Institutes of Health, Bethesda, MD USA
| | - Catherine F. Moore
- grid.21107.350000 0001 2171 9311Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Nathan Shock Drive, Baltimore, MD 21224 USA
| | - Victor Ruiz-Rodado
- grid.94365.3d0000 0001 2297 5165Neuro-Oncology Branch, National Cancer Institute, National Institutes of Health, 10 Center Dr, Bethesda, MD 20892 USA
| | - Mary R. Lee
- grid.94365.3d0000 0001 2297 5165Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD 21224 USA
| | - Paule V. Joseph
- grid.420085.b0000 0004 0481 4802Sensory Science and Metabolism Unit, National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research and National Institute of Nursing Research Division of Intramural Research, 10 Center Dr, Bethesda, MD 20892 USA
| | - Claire M. Fraser
- grid.411024.20000 0001 2175 4264Institute for Genome Sciences, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD USA
| | - Elise M. Weerts
- grid.21107.350000 0001 2171 9311Division of Behavioral Biology, Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Nathan Shock Drive, Baltimore, MD 21224 USA
| | - Lorenzo Leggio
- Clinical Psychoneuroendocrinology and Neuropsychopharmacology Section, Translational Addiction Medicine Branch, National Institute on Drug Abuse Intramural Research Program and National Institute on Alcohol Abuse and Alcoholism Division of Intramural Clinical and Biological Research, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA. .,Center on Compulsive Behaviors, National Institutes of Health, 10 Center Dr, Bethesda, MD, 20892, USA. .,Medication Development Program, National Institute on Drug Abuse Intramural Research Program, National Institutes of Health, 251 Bayview Blvd, Baltimore, MD, 21224, USA. .,Center for Alcohol and Addiction Studies, Department of Behavioral and Social Sciences, Brown University School of Public Health, 121 South Main Street, Providence, RI, USA. .,Division of Addiction Medicine, Department of Medicine, Johns Hopkins University School of Medicine, 733 N Broadway, Baltimore, MD, 21205, USA. .,Department of Neuroscience, Georgetown University Medical Center, 3970 Reservoir Rd NW, Washington, DC, 20007, USA.
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11
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Monnoyer R, Eftedal I, Hjelde A, Deb S, Haugum K, Lautridou J. Functional Profiling Reveals Altered Metabolic Activity in Divers' Oral Microbiota During Commercial Heliox Saturation Diving. Front Physiol 2021; 12:702634. [PMID: 34721054 PMCID: PMC8548618 DOI: 10.3389/fphys.2021.702634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/22/2021] [Indexed: 11/24/2022] Open
Abstract
Background: The extreme environment in saturation diving affects all life forms, including the bacteria that reside on human skin and mucosa. The oral cavity alone is home to hundreds of different bacteria. In this study, we examined the metabolic activity of oral bacteria from healthy males during commercial heliox saturation diving. We focused on environmentally induced changes that might affect the divers’ health and fitness. Methods: We performed pathway abundance analysis using PICRUSt2, a bioinformatics software package that uses marker gene data to compute the metabolic activity of microbial communities. The analysis is based on 16S rRNA metagenomic data generated from the oral microbiota of 23 male divers before, during, and after 4weeks of commercial heliox saturation diving. Environmentally induced changes in bacterial metabolism were computed from differences in predicted pathway abundances at baseline before, versus during, and immediately after saturation diving. Results and Conclusion: The analysis predicted transient changes that were primarily associated with the survival and growth of bacteria in oxygenated environments. There was a relative increase in the abundance of aerobic metabolic pathways and a concomitant decrease in anaerobic metabolic pathways, primarily comprising of energy metabolism, oxidative stress responses, and adenosylcobalamin biosynthesis. Adenosylcobalamin is a bioactive form of vitamin B12 (vitB12), and a reduction in vitB12 biosynthesis may hypothetically affect the divers’ physiology. While host effects of oral bacterial vitamin metabolism are uncertain, this is a finding that concurs with the existing recommendations for vitB12 supplements as part of the divers’ diet, whether to boost antioxidant defenses in bacteria or their host or to improve oxygen transport during saturation diving.
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Affiliation(s)
- Roxane Monnoyer
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Ingrid Eftedal
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway
| | - Astrid Hjelde
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Sanjoy Deb
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Centre for Nutraceuticals, School of Life Sciences, University of Westminster, London, United Kingdom
| | - Kjersti Haugum
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Medical Microbiology, Clinic of Laboratory Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Jacky Lautridou
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
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12
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Xu Y, He Z. Enhanced volatile fatty acids accumulation in anaerobic digestion through arresting methanogenesis by using hydrogen peroxide. WATER ENVIRONMENT RESEARCH : A RESEARCH PUBLICATION OF THE WATER ENVIRONMENT FEDERATION 2021; 93:2051-2059. [PMID: 33894043 DOI: 10.1002/wer.1575] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/23/2021] [Accepted: 04/17/2021] [Indexed: 06/12/2023]
Abstract
Volatile fatty acids (VFAs) can be accumulated as a final product of anaerobic digestion via arresting methanogenesis. Herein, hydrogen peroxide (H2 O2 ) was studied to inhibit methanogenesis for enhancing VFA accumulation with glucose as a substrate. The addition of 0.06 wt.% H2 O2 significantly reduced methane production and led to a VFAs concentration of 1233.1 ± 55.9 mg L-1 , much higher than 429.3 ± 5.6 mg L-1 in the control that did not have H2 O2 addition. The dominated VFAs with H2 O2 were acetic acid and propionic acid. A low H2 O2 dosage of 0.03 wt.% produced 466.3 ± 3.9 mg L-1 more VFAs than that of O2 addition at the similar (theoretical) dosage, but when the dosage was relatively higher, the VFA accumulation with O2 addition became more than that with H2 O2 addition, likely because of stronger oxidation of VFAs by the overly added H2 O2 . A hypothetical mechanism for H2 O2 inhibition suggests that at a low H2 O2 concentration the inhibition is mainly toward methanogenesis to limit their consumption of VFAs and a high H2 O2 concentration starts to inhibit hydrolysis and acidogenesis and/or oxidize VFAs. Those results encourage further exploration of H2 O2 -based arresting methanogenesis for VFAs production.
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Affiliation(s)
- Yanran Xu
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Zhen He
- Department of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
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13
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Song Y, Hervé V, Radek R, Pfeiffer F, Zheng H, Brune A. Characterization and phylogenomic analysis of Breznakiella homolactica gen. nov. sp. nov. indicate that termite gut treponemes evolved from non-acetogenic spirochetes in cockroaches. Environ Microbiol 2021; 23:4228-4245. [PMID: 33998119 DOI: 10.1111/1462-2920.15600] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/12/2021] [Accepted: 05/13/2021] [Indexed: 01/01/2023]
Abstract
Spirochetes of the genus Treponema are surprisingly abundant in termite guts, where they play an important role in reductive acetogenesis. Although they occur in all termites investigated, their evolutionary origin is obscure. Here, we isolated the first representative of 'termite gut treponemes' from cockroaches, the closest relatives of termites. Phylogenomic analysis revealed that Breznakiella homolactica gen. nov. sp. nov. represents the most basal lineage of the highly diverse 'termite cluster I', a deep-branching sister group of Treponemataceae (fam. 'Termitinemataceae') that was present already in the cockroach ancestor of termites and subsequently coevolved with its host. Breznakiella homolactica is obligately anaerobic and catalyses the homolactic fermentation of both hexoses and pentoses. Resting cells produced acetate in the presence of oxygen. Genome analysis revealed the presence of pyruvate oxidase and catalase, and a cryptic potential for the formation of acetate, ethanol, formate, CO2 and H2 - the fermentation products of termite gut isolates. Genes encoding key enzymes of reductive acetogenesis, however, are absent, confirming the hypothesis that the ancestral metabolism of the cluster was fermentative, and that the capacity for acetogenesis from H2 plus CO2 - the most intriguing property among termite gut treponemes - was acquired by lateral gene transfer.
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Affiliation(s)
- Yulin Song
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany
| | - Vincent Hervé
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany
| | - Renate Radek
- Institute of Biology/Zoology, Free University of Berlin, Königin-Luise-Str. 1-3, Berlin, 14195, Germany
| | - Fabienne Pfeiffer
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany
| | - Hao Zheng
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany
| | - Andreas Brune
- Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany
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14
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Monnoyer R, Haugum K, Lautridou J, Flatberg A, Hjelde A, Eftedal I. Shifts in the Oral Microbiota During a Four-Week Commercial Saturation Dive to 200 Meters. Front Physiol 2021; 12:669355. [PMID: 33986696 PMCID: PMC8110926 DOI: 10.3389/fphys.2021.669355] [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: 02/18/2021] [Accepted: 04/06/2021] [Indexed: 01/04/2023] Open
Abstract
During commercial saturation diving, divers live and work under hyperbaric and hyperoxic conditions. The myriads of bacteria that live in and on the human body must adjust to the resultant hyperbaric stress. In this study, we examined the shifts in bacterial content in the oral cavity of saturation divers, using a metagenomic approach to determine the diversity in the composition of bacterial phyla and genera in saliva from 23 male divers before, during, and immediately after 4 weeks of commercial heliox saturation diving to a working depth of circa 200 m. We found that the bacterial diversity fell during saturation, and there was a change in bacterial composition; with a decrease at the phylum level of obligate anaerobe Fusobacteria, and an increase of the relative abundance of Actinobacteria and Proteobacteria. At the genus level, Fusobacterium, Leptotrichia, Oribacterium, and Veillonella decreased, whereas Neisseria and Rothia increased. However, at the end of the decompression, both the diversity and composition of the microbiota returned to pre-dive values. The results indicate that the hyperoxic conditions during saturation may suppress the activity of anaerobes, leaving a niche for other bacteria to fill. The transient nature of the change could imply that hyperbaric heliox saturation has no lasting effect on the oral microbiota, but it is unknown whether or how a shift in oral bacterial diversity and abundance during saturation might impact the divers’ health or well-being.
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Affiliation(s)
- Roxane Monnoyer
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Kjersti Haugum
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway.,Department of Medical Microbiology, Clinic of Laboratory Medicine, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Jacky Lautridou
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Arnar Flatberg
- Department of Clinical and Molecular Medicine, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Astrid Hjelde
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway
| | - Ingrid Eftedal
- Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, NTNU Norwegian University of Science and Technology, Trondheim, Norway.,Faculty of Nursing and Health Sciences, Nord University, Bodø, Norway
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15
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Soni A, Choi J, Brightwell G. Plasma-Activated Water (PAW) as a Disinfection Technology for Bacterial Inactivation with a Focus on Fruit and Vegetables. Foods 2021; 10:foods10010166. [PMID: 33467523 PMCID: PMC7830122 DOI: 10.3390/foods10010166] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 12/11/2022] Open
Abstract
Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.
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Affiliation(s)
- Aswathi Soni
- Food Assurance, AgResearch, Palmerston North 4442, New Zealand;
- Correspondence: ; Tel.: +64-21-0860-7979
| | - Jonghyun Choi
- The New Zealand Institute for Plant and Food Research Ltd., Private Bag 3230, Waikato Mail Centre, Hamilton 3240, New Zealand;
| | - Gale Brightwell
- Food Assurance, AgResearch, Palmerston North 4442, New Zealand;
- New Zealand Food Safety Science Research Centre, Palmerston North 4474, New Zealand
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16
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Oxidative stress responses of pathogen bacteria in poultry to plasma-activated lactic acid solutions. Food Control 2020. [DOI: 10.1016/j.foodcont.2020.107355] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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17
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Mahdy A, Song Y, Salama A, Qiao W, Dong R. Simultaneous H 2S mitigation and methanization enhancement of chicken manure through the introduction of the micro-aeration approach. CHEMOSPHERE 2020; 253:126687. [PMID: 32298914 DOI: 10.1016/j.chemosphere.2020.126687] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
The impact on H2S alleviation and methane yield enhancement after submitting the anaerobic digestion of chicken manure to a finite amount of air was investigated. The largest reduction in the H2S biogas content (58% lower) occurred when air intensity of 30 ml/g VSin was injected into the reactors. Consequently, a maximum methane yield (335 mL-g VSin-1), which was 77% higher than the control, was concurrently achieved. Slight sulfate accumulation (<330 mg L-1) was observed inside the micro-aerated digesters with higher air intensities, suggesting a suppression of sulfide inhibition. Bacterial diversity/richness was enhanced in these digesters while the relative abundance of Methanocelleus increased by 36%. The most important contributing factor to enhancement was the synergistic effect resulting from increments in the hydrolysis rate and the suppression of sulfide inhibition. The results highlighted the potential of in situ H2S mitigation with the added benefit of methane yield enhancement.
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Affiliation(s)
- Ahmed Mahdy
- College of Engineering, China Agricultural University, Beijing, 100083, China; Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511, Zagazig, Egypt
| | - Yunlong Song
- College of Engineering, China Agricultural University, Beijing, 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing, 100083, China
| | - Ali Salama
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, 44511, Zagazig, Egypt
| | - Wei Qiao
- College of Engineering, China Agricultural University, Beijing, 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing, 100083, China.
| | - Renjie Dong
- College of Engineering, China Agricultural University, Beijing, 100083, China; State R&D Center for Efficient Production and Comprehensive Utilization of Biobased Gaseous Fuels, Energy Authority, National Development, and Reform Committee, Beijing, 100083, China
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18
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Yu N, Guo B, Zhang Y, Zhang L, Zhou Y, Liu Y. Different micro-aeration rates facilitate production of different end-products from source-diverted blackwater. WATER RESEARCH 2020; 177:115783. [PMID: 32283434 DOI: 10.1016/j.watres.2020.115783] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 03/24/2020] [Accepted: 04/01/2020] [Indexed: 06/11/2023]
Abstract
The effects of micro-aeration on the performance of anaerobic sequencing batch reactors (ASBR) for blackwater treatment were investigated in this study. Different micro-aeration rates, 0, 5, 10, 50, and 150 mg O2/L-reactor/cycle, and their effect on the hydrolysis, acidogenesis, and methanogenesis of blackwater were evaluated and compared at ambient temperature. Source-diverted blackwater (toilet water) contains high organic contents which can be recovered as biogas. Previous studies have found that anaerobic digestion of blackwater without micro-aeration can only recover upwards of less than 40% of chemical oxygen demand (COD) to methane at room temperature due to the low hydrolysis rate of biomass content in blackwater. This study achieved increases in blackwater hydrolysis (from 34.7% to 48.7%) and methane production (from 39.6% to 50.7%) with controlled micro-aeration (5 mg O2/L-reactor/cycle). The microbial analysis results showed that hydrolytic/fermentative bacteria and acetoclastic methanogens (e.g. Methanosaeta) were in higher abundances in low-dose micro-aeration reactors (5 and 10 mg O2/L-reactor/cycle), which facilitated syntrophic interactions between microorganisms. The relative abundance of oxygen-tolerant methanogen such as Methanosarcina greatly increased (from 1.5% to 11.4%) after oxygen injection. High oxygen dosages (50 and 150 mg O2/L-reactor/cycle) led to reduced methane production and higher accumulation of volatile fatty acids, largely due to the oxygen inhibition on methanogens and degradation of organic matters by aerobic growth and respiration, as indicated by the predicted metagenome functions. By combining reactor performance results and microbial community analyses, this study demonstrated that low-dose micro-aeration improves blackwater biomethane recovery by enhancing hydrolysis efficiency and promoting the development of a functional microbial population, while medium to high-dose micro-aeration reduced the activities of certain anaerobes. It was also observed that medium-dose micro-aeration maximizes VFA accumulation, which may be used in two-stage anaerobic digesters.
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Affiliation(s)
- Najiaowa Yu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Bing Guo
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Yingdi Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Lei Zhang
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Yun Zhou
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada
| | - Yang Liu
- Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, T6G 1H9, Canada.
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19
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Chen Q, Wu W, Qi D, Ding Y, Zhao Z. Review on microaeration-based anaerobic digestion: State of the art, challenges, and prospectives. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 710:136388. [PMID: 31923694 DOI: 10.1016/j.scitotenv.2019.136388] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 12/26/2019] [Accepted: 12/26/2019] [Indexed: 06/10/2023]
Abstract
Microaeration (dosing small quantities of air or oxygen) is an effective approach to facilitate anaerobic digestion (AD) process and has gained increased attention in recent years. The underlying mechanisms of the facilitation effect of microaeration on AD process were reviewed in terms of accelerating hydrolysis, scavenging hydrogen sulfide, and affecting microbial diversity. Process parameters and control strategies were summarized to reveal considerable factors in implementing microaeration-based AD process. In addition, current applications, including lab-, pilot- and full-scale level cases, were summarized to provide guidance for further improvement in large-scale applications. The challenges and future perspectives were also highlighted to promote the development of AD process associated with microaeration.
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Affiliation(s)
- Qing Chen
- Marine Engineering College, Dalian Maritime University, Dalian 116026, PR China
| | - Wanqing Wu
- Marine Engineering College, Dalian Maritime University, Dalian 116026, PR China.
| | - Dacheng Qi
- Marine Engineering College, Dalian Maritime University, Dalian 116026, PR China
| | - Yihong Ding
- Marine Engineering College, Dalian Maritime University, Dalian 116026, PR China
| | - Zihao Zhao
- Marine Engineering College, Dalian Maritime University, Dalian 116026, PR China
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20
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Ślesak I, Kula M, Ślesak H, Miszalski Z, Strzałka K. How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the evolution of life on Earth. Free Radic Biol Med 2019; 140:61-73. [PMID: 30862543 DOI: 10.1016/j.freeradbiomed.2019.03.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/01/2019] [Accepted: 03/05/2019] [Indexed: 10/27/2022]
Abstract
One of the former definitions of "obligate anaerobiosis" was based on three main criteria: 1) it occurs in organisms, so-called obligate anaerobes, which live in environments without oxygen (O2), 2) O2-dependent (aerobic) respiration, and 3) antioxidant enzymes are absent in obligate anaerobes. In contrast, aerobes need O2 in order to grow and develop properly. Obligate (or strict) anaerobes belong to prokaryotic microorganisms from two domains, Bacteria and Archaea. A closer look at anaerobiosis covers a wide range of microorganisms that permanently or in a time-dependent manner tolerate different concentrations of O2 in their habitats. On this basis they can be classified as obligate/facultative anaerobes, microaerophiles and nanaerobes. Paradoxically, O2 tolerance in strict anaerobes is usually, as in aerobes, associated with the activity of the antioxidant response system, which involves different antioxidant enzymes responsible for removing excess reactive oxygen species (ROS). In our opinion, the traditional definition of "obligate anaerobiosis" loses its original sense. Strict anaerobiosis should only be restricted to the occurrence of O2-independent pathways involved in energy generation. For that reason, a term better than "obligate anaerobes" would be O2/ROS tolerant anaerobes, where the role of the O2/ROS detoxification system is separated from O2-independent metabolic pathways that supply energy. Ubiquitous key antioxidant enzymes like superoxide dismutase (SOD) and superoxide reductase (SOR) in contemporary obligate anaerobes might suggest that their origin is ancient, maybe even the beginning of the evolution of life on Earth. It cannot be ruled out that c. 3.5 Gyr ago, local microquantities of O2/ROS played a role in the evolution of the last universal common ancestor (LUCA) of all modern organisms. On the basis of data in the literature, the hypothesis that LUCA could be an O2/ROS tolerant anaerobe is discussed together with the question of the abiotic sources of O2/ROS and/or the early evolution of cyanobacteria that perform oxygenic photosynthesis.
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Affiliation(s)
- Ireneusz Ślesak
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Krakow, Poland.
| | - Monika Kula
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Krakow, Poland.
| | - Halina Ślesak
- Institute of Botany, Jagiellonian University, Gronostajowa 9, 30-387, Krakow, Poland.
| | - Zbigniew Miszalski
- The Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Niezapominajek 21, 30-239, Krakow, Poland.
| | - Kazimierz Strzałka
- Malopolska Centre of Biotechnology, Jagiellonian University, Gronostajowa 7A, 30-387, Krakow, Poland; Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Krakow, Poland.
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21
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Šantl-Temkiv T, Gosewinkel U, Starnawski P, Lever M, Finster K. Aeolian dispersal of bacteria in southwest Greenland: their sources, abundance, diversity and physiological states. FEMS Microbiol Ecol 2019; 94:4898009. [PMID: 29481623 DOI: 10.1093/femsec/fiy031] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 02/21/2018] [Indexed: 01/18/2023] Open
Abstract
The Arctic is undergoing dramatic climatic changes that cause profound transformations in its terrestrial ecosystems and consequently in the microbial communities that inhabit them. The assembly of these communities is affected by aeolian deposition. However, the abundance, diversity, sources and activity of airborne microorganisms in the Arctic are poorly understood. We studied bacteria in the atmosphere over southwest Greenland and found that the diversity of bacterial communities correlated positively with air temperature and negatively with relative humidity. The communities consisted of 1.3×103 ± 1.0×103 cells m-3, which were aerosolized from local terrestrial environments or transported from marine, glaciated and terrestrial surfaces over long distances. On average, airborne bacterial cells displayed a high activity potential, reflected in the high 16S rRNA copy number (590 ± 300 rRNA cell-1), that correlated positively with water vapor pressure. We observed that bacterial clades differed in their activity potential. For instance, a high activity potential was seen for Rubrobacteridae and Clostridiales, while a low activity potential was observed for Proteobacteria. Of those bacterial families that harbor ice-nucleation active species, which are known to facilitate freezing and may thus be involved in cloud and rain formation, cells with a high activity potential were rare in air, but were enriched in rain.
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Affiliation(s)
- Tina Šantl-Temkiv
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus, Denmark.,Department of Bioscience, Microbiology Section, Aarhus University, Ny Munkegade 116, 8000 Aarhus, Denmark
| | - Ulrich Gosewinkel
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
| | - Piotr Starnawski
- Centre for Geomicrobiology, Aarhus University, 116 Ny Munkegade, 8000 Aarhus, Denmark
| | - Mark Lever
- Centre for Geomicrobiology, Aarhus University, 116 Ny Munkegade, 8000 Aarhus, Denmark.,ETH Zürich, Department of Environmental Systems Science, Universitätsstrasse 16, 8092 Zurich, Switzerland
| | - Kai Finster
- Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus, Denmark.,Department of Bioscience, Microbiology Section, Aarhus University, Ny Munkegade 116, 8000 Aarhus, Denmark
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22
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Aslam S, Lan XR, Zhang BW, Chen ZL, Wang L, Niu DK. Aerobic prokaryotes do not have higher GC contents than anaerobic prokaryotes, but obligate aerobic prokaryotes have. BMC Evol Biol 2019; 19:35. [PMID: 30691392 PMCID: PMC6350292 DOI: 10.1186/s12862-019-1365-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 01/17/2019] [Indexed: 12/17/2022] Open
Abstract
Background Among the four bases, guanine is the most susceptible to damage from oxidative stress. Replication of DNA containing damaged guanines results in G to T mutations. Therefore, the mutations resulting from oxidative DNA damage are generally expected to predominantly consist of G to T (and C to A when the damaged guanine is not in the reference strand) and result in decreased GC content. However, the opposite pattern was reported 16 years ago in a study of prokaryotic genomes. Although that result has been widely cited and confirmed by nine later studies with similar methods, the omission of the effect of shared ancestry requires a re-examination of the reliability of the results. Results When aerobic and obligate aerobic prokaryotes were mixed together and anaerobic and obligate anaerobic prokaryotes were mixed together, phylogenetic controlled analyses did not detect significant difference in GC content between aerobic and anaerobic prokaryotes. This result is consistent with two generally neglected studied that had accounted for the phylogenetic relationship. However, when obligate aerobic prokaryotes were compared with aerobic prokaryotes, anaerobic prokaryotes, and obligate anaerobic prokaryotes separately using phylogenetic regression analysis, a significant positive association was observed between aerobiosis and GC content, no matter it was calculated from whole genome sequences or the 4-fold degenerate sites of protein-coding genes. Obligate aerobes have significantly higher GC content than aerobes, anaerobes, and obligate anaerobes. Conclusions The positive association between aerobiosis and GC content could be attributed to a mutational force resulting from incorporation of damaged deoxyguanosine during DNA replication rather than oxidation of the guanine nucleotides within DNA sequences. Our results indicate a grade in the aerobiosis-associated mutational force, strong in obligate aerobes, moderate in aerobes, weak in anaerobes and obligate anaerobes. Electronic supplementary material The online version of this article (10.1186/s12862-019-1365-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sidra Aslam
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Xin-Ran Lan
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Bo-Wen Zhang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Zheng-Lin Chen
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Li Wang
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Deng-Ke Niu
- MOE Key Laboratory for Biodiversity Science and Ecological Engineering and Beijing Key Laboratory of Gene Resource and Molecular Development, College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
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Biofilm activity on corrosion of API 5L X65 steel weld bead. Colloids Surf B Biointerfaces 2018; 172:43-50. [DOI: 10.1016/j.colsurfb.2018.08.026] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/26/2018] [Accepted: 08/14/2018] [Indexed: 11/21/2022]
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24
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Zuo F, Yu R, Xiao M, Khaskheli GB, Sun X, Ma H, Ren F, Zhang B, Chen S. Transcriptomic analysis of Bifidobacterium longum subsp. longum BBMN68 in response to oxidative shock. Sci Rep 2018; 8:17085. [PMID: 30459453 PMCID: PMC6244367 DOI: 10.1038/s41598-018-35286-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 10/18/2018] [Indexed: 02/08/2023] Open
Abstract
Bifidobacterium longum strain BBMN68 is sensitive to low concentrations of oxygen. A transcriptomic study was performed to identify candidate genes for B. longum BBMN68's response to oxygen treatment (3%, v/v). Expression of genes and pathways of B. longum BBMN68 involved in nucleotide metabolism, amino acid transport, protein turnover and chaperones increased, and that of carbohydrate metabolism, translation and biogenesis decreased to adapt to the oxidative stress. Notably, expression of two classes of ribonucleotide reductase (RNR), which are important for deoxyribonucleotide biosynthesis, was rapidly and persistently induced. First, the class Ib RNR NrdHIEF was immediately upregulated after 5 min oxygen exposure, followed by the class III RNR NrdDG, which was upregulated after 20 min of exposure. The upregulated expression of branched-chain amino acids and tetrahydrofolate biosynthesis-related genes occurred in bifidobacteria in response to oxidative stress. These change toward to compensate for DNA and protein damaged by reactive oxygen species (ROS). In addition, oxidative stress resulted in improved B. longum BBMN68 cell hydrophobicity and autoaggregation. These results provide a rich resource for our understanding of the response mechanisms to oxidative stress in bifidobacteria.
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Affiliation(s)
- Fanglei Zuo
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.,Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.,Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-10691, Stockholm, Sweden
| | - Rui Yu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.,Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Man Xiao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.,Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Gul Bahar Khaskheli
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.,Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Xiaofei Sun
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Huiqin Ma
- Department of Fruit Tree Sciences, College of Horticulture, China Agricultural University, Beijing, 100193, P. R. China
| | - Fazheng Ren
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China
| | - Bing Zhang
- Core Genomic Facility, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100101, P. R. China
| | - Shangwu Chen
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China. .,Key Laboratory of Functional Dairy, Department of Food Science and Engineering, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, P. R. China.
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25
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Nguyen D, Khanal SK. A little breath of fresh air into an anaerobic system: How microaeration facilitates anaerobic digestion process. Biotechnol Adv 2018; 36:1971-1983. [DOI: 10.1016/j.biotechadv.2018.08.007] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 08/07/2018] [Accepted: 08/20/2018] [Indexed: 10/28/2022]
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26
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Landscape topography structures the soil microbiome in arctic polygonal tundra. Nat Commun 2018; 9:777. [PMID: 29472560 PMCID: PMC5823929 DOI: 10.1038/s41467-018-03089-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 01/18/2018] [Indexed: 11/08/2022] Open
Abstract
In the Arctic, environmental factors governing microbial degradation of soil carbon (C) in active layer and permafrost are poorly understood. Here we determined the functional potential of soil microbiomes horizontally and vertically across a cryoperturbed polygonal landscape in Alaska. With comparative metagenomics, genome binning of novel microbes, and gas flux measurements we show that microbial greenhouse gas (GHG) production is strongly correlated to landscape topography. Active layer and permafrost harbor contrasting microbiomes, with increasing amounts of Actinobacteria correlating with decreasing soil C in permafrost. While microbial functions such as fermentation and methanogenesis were dominant in wetter polygons, in drier polygons genes for C mineralization and CH4 oxidation were abundant. The active layer microbiome was poised to assimilate N and not to release N2O, reflecting low N2O flux measurements. These results provide mechanistic links of microbial metabolism to GHG fluxes that are needed for the refinement of model predictions. The role of ecosystem structure in microbial activity related to greenhouse gas production is poorly understood. Here, Taş and colleagues show that microbial communities and ecosystem function vary across fine-scale topography in a polygonal tundra.
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27
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Correia RRS, Guimarães JRD. Impacts of crab bioturbation and local pollution on sulfate reduction, Hg distribution and methylation in mangrove sediments, Rio de Janeiro, Brazil. MARINE POLLUTION BULLETIN 2016; 109:453-460. [PMID: 27269386 DOI: 10.1016/j.marpolbul.2016.05.028] [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: 01/07/2016] [Revised: 05/09/2016] [Accepted: 05/14/2016] [Indexed: 06/06/2023]
Abstract
Mercury (Hg) and methylmercury (MeHg) are highly toxic and poorly studied in mangroves. Burrowing Uca crabs change sediment topography and biogeochemistry and thus may affect Hg distribution and MeHg formation. We studied added (203)Hg distribution, Me(203)Hg formation and sulfate reduction rates (SRR) in sediment aquariums containing Uca leptodactyla; and analyzed profiles of Me(203)Hg formation and SRR in sediment cores from two mangroves with distinct environmental impacts. MeHg formation and SRR were higher in the top (≤6cm) sediment and there was no significant difference in Hg methylation in more or less impacted mangroves. In aquariums, crab bioturbation favored Hg retention in the sediment. In the treatment without crabs, Hg volatilization and water Hg concentrations were higher. Hg methylation was higher in bioturbated aquariums but SRR were similar in both treatments. These findings suggest that bioturbating activity favors Hg retention in sediment but also promotes MeHg formation near the surface.
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Affiliation(s)
- Raquel Rose Silva Correia
- Laboratório de Traçadores Wolfgang C. Pfeiffer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G/CCS/Ilha do Fundão, Rio de Janeiro (RJ), CEP: 21941-902, Brazil.
| | - Jean Remy Davée Guimarães
- Laboratório de Traçadores Wolfgang C. Pfeiffer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G/CCS/Ilha do Fundão, Rio de Janeiro (RJ), CEP: 21941-902, Brazil.
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Abstract
Early parental influence led me first to medical school, but after developing a passion for biochemistry and sensing the need for a deeper foundation, I changed to chemistry. During breaks between semesters, I worked in various biochemistry labs to acquire a feeling for the different areas of investigation. The scientific puzzle that fascinated me most was the metabolism of the anaerobic bacterium Clostridium kluyveri, which I took on in 1965 in Karl Decker's lab in Freiburg, Germany. I quickly realized that little was known about the biochemistry of strict anaerobes such as clostridia, methanogens, acetogens, and sulfate-reducing bacteria and that these were ideal model organisms to study fundamental questions of energy conservation, CO2 fixation, and the evolution of metabolic pathways. My passion for anaerobes was born then and is unabated even after 50 years of study.
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Affiliation(s)
- Rudolf Kurt Thauer
- Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany;
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29
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Tegtmeier D, Thompson CL, Schauer C, Brune A. Oxygen Affects Gut Bacterial Colonization and Metabolic Activities in a Gnotobiotic Cockroach Model. Appl Environ Microbiol 2016; 82:1080-1089. [PMID: 26637604 PMCID: PMC4751835 DOI: 10.1128/aem.03130-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/24/2015] [Indexed: 12/21/2022] Open
Abstract
The gut microbiota of termites and cockroaches represents complex metabolic networks of many diverse microbial populations. The distinct microenvironmental conditions within the gut and possible interactions among the microorganisms make it essential to investigate how far the metabolic properties of pure cultures reflect their activities in their natural environment. We established the cockroach Shelfordella lateralis as a gnotobiotic model and inoculated germfree nymphs with two bacterial strains isolated from the guts of conventional cockroaches. Fluorescence microscopy revealed that both strains specifically colonized the germfree hindgut. In diassociated cockroaches, the facultatively anaerobic strain EbSL (a new species of Enterobacteriaceae) always outnumbered the obligately anaerobic strain FuSL (a close relative of Fusobacterium varium), irrespective of the sequence of inoculation, which showed that precolonization by facultatively anaerobic bacteria does not necessarily favor colonization by obligate anaerobes. Comparison of the fermentation products of the cultures formed in vitro with those accumulated in situ indicated that the gut environment strongly affected the metabolic activities of both strains. The pure cultures formed the typical products of mixed-acid or butyrate fermentation, whereas the guts of gnotobiotic cockroaches accumulated mostly lactate and acetate. Similar shifts toward more-oxidized products were observed when the pure cultures were exposed to oxygen, which corroborated the strong effects of oxygen on the metabolic fluxes previously observed in termite guts. Oxygen microsensor profiles of the guts of germfree, gnotobiotic, and conventional cockroaches indicated that both gut tissue and microbiota contribute to oxygen consumption and suggest that the oxygen status influences the colonization success.
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Affiliation(s)
- Dorothee Tegtmeier
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
| | - Claire L Thompson
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
| | - Christine Schauer
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
| | - Andreas Brune
- Department of Biogeochemistry, Max Planck Institute for Terrestrial Microbiology, and LOEWE Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Marburg, Germany
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30
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Electrochemical study of a new non-heme iron complex-modified carbon ionic liquid electrode with electrocatalytic activity towards hydrogen peroxide reduction. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.10.074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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31
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Bellucci M, Botticella G, Francavilla M, Beneduce L. Inoculum pre-treatment affects the fermentative activity of hydrogen-producing communities in the presence of 5-hydroxymethylfurfural. Appl Microbiol Biotechnol 2015; 100:493-504. [PMID: 26428244 DOI: 10.1007/s00253-015-7002-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 09/02/2015] [Accepted: 09/10/2015] [Indexed: 11/27/2022]
Abstract
To enhance the productivity of mixed microbial cultures for fermentative bio-hydrogen production, chemical-physical pre-treatments of the original seed are needed to suppress the activity of hydrogen (H2)-consuming microbes. This approach might influence negatively the composition and diversity of the hydrogen-producing community with consequences on the functional stability of the H2-producing systems in case of perturbations. In this study, we aimed at investigating the effect of different types of pre-treatment on the performance of hydrogen production systems in the presence of an inhibitor, such as 5-hydroxymethylfurfural (HMF). The efficiency and the microbial community structure of batch reactors amended with HMF and inoculated with non-pretreated and pretreated (acid, heat shock, and aeration) anaerobic sludge were evaluated and compared with control systems. The type of pre-treatments influenced the microbial community assembly and activity in inhibited systems, with significant effect on the performance. Cumulative H2 production tests showed that the pre-aerated systems (control and HMF inhibited) were the most efficient, while the difference of the lag phase of the pre-acidified control and HMF-added test was negligible. Analyses of the structure of the enriched microbial community in the systems through PCR-denaturing gradient gel electrophoresis (DGGE) followed by band sequencing revealed that the differences in performance were mostly related to shifts in the metabolic pathways rather than in the predominant species. In conclusion, the findings suggest that the use of specific inoculum pre-treatment could contribute to regulate the metabolic activity of the fermentative H2-producing bacteria in order to enhance the bio-energy production.
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Affiliation(s)
- Micol Bellucci
- Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università degli Studi di Foggia, Via Napoli 25, Foggia, Italy
- STAR Agroenergy Research Group, University of Foggia, Via Gramsci, 89-91, Foggia, Italy
| | - Giuseppe Botticella
- Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università degli Studi di Foggia, Via Napoli 25, Foggia, Italy
| | - Matteo Francavilla
- STAR Agroenergy Research Group, University of Foggia, Via Gramsci, 89-91, Foggia, Italy
| | - Luciano Beneduce
- Dipartimento di Scienze Agrarie, Alimentari ed Ambientali, Università degli Studi di Foggia, Via Napoli 25, Foggia, Italy.
- STAR Agroenergy Research Group, University of Foggia, Via Gramsci, 89-91, Foggia, Italy.
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32
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Oberg TS, Ward RE, Steele JL, Broadbent JR. Transcriptome analysis of Bifidobacterium longum strains that show a differential response to hydrogen peroxide stress. J Biotechnol 2015; 212:58-64. [PMID: 26299205 DOI: 10.1016/j.jbiotec.2015.06.405] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2015] [Revised: 06/16/2015] [Accepted: 06/19/2015] [Indexed: 01/02/2023]
Abstract
Consumer and commercial interest in foods containing probiotic bifidobacteria is increasing. However, because bifidobacteria are anaerobic, oxidative stress can diminish cell viability during production and storage of bioactive foods. We previously found Bifidobacterium longum strain NCC2705 had significantly greater intrinsic and inducible resistance to hydrogen peroxide (H2O2) than strain D2957. Here, we explored the basis for these differences by examining the transcriptional responses of both strains to sub-lethal H2O2 exposure for 5- or 60-min. Strain NCC2705 had 288 genes that were differentially expressed after the 5-min treatment and 114 differentially expressed genes after the 60-min treatment. In contrast, strain D2957 had only 21 and 90 differentially expressed genes after the 5- and 60-min treatments, respectively. Both strains showed up-regulation of genes coding enzymes implicated in oxidative stress resistance, such as thioredoxin, thioredoxin reductase, peroxiredoxin, ferredoxin, glutaredoxin, and anaerobic ribonucleotide reductase, but induction levels were typically highest in NCC2705. Compared to D2957, NCC2705 also had more up-regulated genes involved in transcriptional regulation and more down-regulated genes involved in sugar transport and metabolism. These results provide a greater understanding of the molecular basis for oxidative stress resistance in B. longum and the factors that contribute to strain-to-strain variability in survival in bioactive food products.
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Affiliation(s)
- Taylor S Oberg
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, 8700 Old Main Hill, Logan, UT 84322-8700, USA.
| | - Robert E Ward
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, 8700 Old Main Hill, Logan, UT 84322-8700, USA
| | - James L Steele
- Department of Food Science, University of Wisconsin, 1605 Linden Drive, Madison, WI 53706-1565, USA
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Sciences, Utah State University, 8700 Old Main Hill, Logan, UT 84322-8700, USA
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33
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Bioaccessible antioxidants in milk fermented by Bifidobacterium longum subsp. longum strains. BIOMED RESEARCH INTERNATIONAL 2015; 2015:169381. [PMID: 25802836 PMCID: PMC4352726 DOI: 10.1155/2015/169381] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 09/25/2014] [Indexed: 12/20/2022]
Abstract
Bifidobacterium longum subsp. longum is among the dominant species of the human gastrointestinal microbiota and could thus have potential as probiotics. New targets such as antioxidant properties have interest for beneficial effects on health. The objective of this study was to evaluate the bioaccessibility of antioxidants in milk fermented by selected B. longum subsp. longum strains during in vitro dynamic digestion. The antioxidant capacity of cell extracts from 38 strains, of which 32 belong to B. longum subsp. longum, was evaluated with the ORAC (oxygen radical absorbance capacity) method. On the basis of screening and gene sequence typing by multilocus locus sequence analysis (MLSA), five strains were chosen for fermenting reconstituted skim milk. Antioxidant capacity varied among the strains tested (P = 0.0009). Two strains of B. longum subsp. longum (CUETM 172 and 171) showed significantly higher ORAC values than the other bifidobacteria strains. However, there does not appear to be a relationship between gene sequence types and antioxidant capacity. The milk fermented by each of the five strains selected (CUETM 268, 172, 245, 247, or PRO 16-10) did not have higher initial ORAC values compared to the nonfermented milk samples. However, higher bioaccessibility of antioxidants in fermented milk (175–358%) was observed during digestion.
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Lin KC, Wu TH, Chen SM. Electrocodeposition of silver and silicomolybdate hybrid nanocomposite for nonenzymatic hydrogen peroxide sensor. RSC Adv 2015. [DOI: 10.1039/c5ra04366b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Electrocodeposition of silver and silicomolybdate hybrid nanocomposite using negatively charged silicomolybdate to induce silver ions to co-deposit on electrode surface.
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Affiliation(s)
- Kuo Chiang Lin
- Electroanalysis and Bioelectrochemistry Lab
- Department of Chemical Engineering and Biotechnology
- National Taipei University of Technology
- Taipei 106
- Republic Of China
| | - Tsung Han Wu
- Electroanalysis and Bioelectrochemistry Lab
- Department of Chemical Engineering and Biotechnology
- National Taipei University of Technology
- Taipei 106
- Republic Of China
| | - Shen Ming Chen
- Electroanalysis and Bioelectrochemistry Lab
- Department of Chemical Engineering and Biotechnology
- National Taipei University of Technology
- Taipei 106
- Republic Of China
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35
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Survival of the anaerobic fungus Orpinomyces sp. strain C1A after prolonged air exposure. Sci Rep 2014; 4:6892. [PMID: 25367149 PMCID: PMC4219153 DOI: 10.1038/srep06892] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Accepted: 10/15/2014] [Indexed: 11/08/2022] Open
Abstract
Anaerobic fungi are efficient plant biomass degraders and represent promising agents for a variety of biotechnological applications. We evaluated the tolerance of an anaerobic fungal isolate, Orpinomyces sp. strain C1A, to air exposure in liquid media using soluble (cellobiose) and insoluble (dried switchgrass) substrates. Strain C1A grown on cellobiose survived for 11, and 13.5 hours following air exposure when grown under planktonic, and immobilized conditions, respectively. When grown on switchgrass media, strain C1A exhibited significantly enhanced air tolerance and survived for 168 hours. The genome of strain C1A lacked a catalase gene, but contained superoxide dismutase and glutathione peroxidase genes. Real time PCR analysis indicated that superoxide dismutase, but not glutathione peroxidase, exhibits a transient increase in expression level post aeration. Interestingly, the C1A superoxide dismutase gene of strain C1A appears to be most closely related to bacterial SODs, which implies its acquisition from a bacterial donor via cross kingdom horizontal gene transfer during Neocallimastigomycota evolution. We conclude that strain C1A utilizes multiple mechanisms to minimize the deleterious effects of air exposure such as physical protection and the production of oxidative stress enzymes.
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36
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Grigor’eva NV, Tsaplina IA, Panyushkina AE, Kondrat’eva TF. Optimization of bioleaching and oxidation of gold-bearing pyrite-arsnopyrite ore concentrate in batch mode. Microbiology (Reading) 2014. [DOI: 10.1134/s0026261714040043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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37
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Yu CL, Lo NC, Cheng H, Tsuda T, Sakamoto T, Chen YH, Kuwabata S, Chen PY. An ionic liquid-Fe3O4 nanoparticles-graphite composite electrode used for nonenzymatic electrochemical determination of hydrogen peroxide. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2014.07.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Sheng Y, Abreu IA, Cabelli DE, Maroney MJ, Miller AF, Teixeira M, Valentine JS. Superoxide dismutases and superoxide reductases. Chem Rev 2014; 114:3854-918. [PMID: 24684599 PMCID: PMC4317059 DOI: 10.1021/cr4005296] [Citation(s) in RCA: 569] [Impact Index Per Article: 56.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Yuewei Sheng
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
| | - Isabel A. Abreu
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
- Instituto
de Biologia Experimental e Tecnológica, Av. da República,
Qta. do Marquês, Estação Agronómica Nacional,
Edificio IBET/ITQB, 2780-157, Oeiras, Portugal
| | - Diane E. Cabelli
- Chemistry
Department, Brookhaven National Laboratory, Upton, New York 11973, United States
| | - Michael J. Maroney
- Department
of Chemistry, University of Massachusetts
Amherst, Amherst, Massachusetts 01003, United States
| | - Anne-Frances Miller
- Department
of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055, United States
| | - Miguel Teixeira
- Instituto
de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157, Oeiras, Portugal
| | - Joan Selverstone Valentine
- Department
of Chemistry and Biochemistry, University
of California Los Angeles, Los
Angeles, California 90095, United States
- Department
of Bioinspired Sciences, Ewha Womans University, Seoul 120-750, Republic of Korea
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Cheng H, Chen HT, Hsien KC, Lu CY, Chen PY. New copper complexes incorporated with the one-step preparation of ionic liquid carbon paste electrode for highly selectively reducing hydrogen peroxide. Electrochem commun 2014. [DOI: 10.1016/j.elecom.2013.12.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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40
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Correia RRS, Martins de Oliveira DC, Guimarães JRD. Mercury methylation in mesocosms with and without the aquatic macrophyte Eichhornia crassipes (mart.) Solms. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2013; 96:124-130. [PMID: 23829936 DOI: 10.1016/j.ecoenv.2013.06.002] [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: 02/26/2013] [Revised: 05/29/2013] [Accepted: 06/03/2013] [Indexed: 06/02/2023]
Abstract
Mercury is a toxic pollutant and spreads to several compartments in the environment. Previous in-vitro studies showed that roots of aquatic macrophytes are sites of methylmercury formation, performed mainly by sulfate-reducing bacteria (SRB). The objective of this study was to observe MMHg formation and distribution among filtered water (0.2µm), suspended and settled particles and macrophyte roots during seventeen days, in (203)Hg- spiked mesocosms with and without live Eichhornia crassipes whole plants and a SRB inhibitor. Root samples were also incubated in-vitro for comparison of MM(203)Hg formation under in-vitro and in-vivo conditions. To evaluate the effect of SRB inhibition by sodium molybdate on total heterotrophic activity, the latter was measured by (3)H-leucine uptake. Inhibition of Hg methylation by sodium molybdate decreased with time in mesocosms. MMHg averaged 10, 12.4 and 0.23 percent of total (203)Hg present in filtered water, suspended particles and roots respectively. In vitro MMHg formation in roots averaged 5.54 percent of total added (203)Hg, with a clearer SRB inhibition effect than in mesocosms. Though significant, MMHg formation in roots from in-vivo mesocosms was one order of magnitude lower than previously found in in-vitro incubations of roots alone.
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Affiliation(s)
- Raquel Rose Silva Correia
- Laboratório de Traçadores Wolfgang C. Pfeiffer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G/CCS/Ilha do Fundão, Rio de Janeiro (RJ), CEP 21941-902, Brazil.
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41
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Korneeva VA, Bryukhanov AL, Pimenov NV. Molecular detection of methanogenic archaea in the Black Sea oxidized waters. Microbiology (Reading) 2013. [DOI: 10.1134/s002626171304005x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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42
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Gao D, Gao Z, Zhu G. Antioxidant effects of Lactobacillus plantarum via activation of transcription factor Nrf2. Food Funct 2013; 4:982-9. [PMID: 23681127 DOI: 10.1039/c3fo30316k] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present study was undertaken to investigate antioxidant and hypolipidemic effects, as well as its molecular mechanism of wild Lactobacillus plantarum FC225 isolated from fermented cabbages. The scavenging activities of superoxide anion radical, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and hydroxyl radical were enhanced by FC225 treatment. The strain FC225 also attenuated hyperlipidemic status, decreased lipid peroxidation, plasma cholesterol, triglyceride and low-density lipoprotein cholesterol levels in high fat diet-fed mice. Meanwhile, FC225 therapy could significantly elevate the activities of superoxidase dismutase and glutathione peroxidase, and decrease the content of malondialdehyde (MDA) in liver homogenates, whereas there was no change in catalase activity in high fat diet-fed mice. In addition, compared with the control group, FC225 markedly elevated the gene expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which was in parallel with the increased value of CD4+/CD8+ ratio in the FC225-treated hyperlipidemic mice. The results demonstrated that the strain FC225 confers hypolipidemic and antioxidant protective effects which may be attributable to Nrf2 signal pathway mediated antioxidant enzyme expression.
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Affiliation(s)
- Dawei Gao
- Applying Chemistry Key Lab of Hebei Province, College of Environmental and Chemical Engineering, Yanshan University, no.438 Hebei Street, Qinhuangdao 066004, China.
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Abstract
Competition for molecular oxygen (O(2)) among respiratory microorganisms is intense because O(2) is a potent electron acceptor. This competition leads to the formation of microoxic environments wherever microorganisms congregate in aquatic, terrestrial and host-associated communities. Bacteria can harvest O(2) present at low, even nanomolar, concentrations using high-affinity terminal oxidases. Here, we report the results of surveys searching for high-affinity terminal oxidase genes in sequenced bacterial genomes and shotgun metagenomes. The results indicate that bacteria with the potential to respire under microoxic conditions are phylogenetically diverse and intriguingly widespread in nature. We explore the implications of these findings by highlighting the importance of microaerobic metabolism in host-associated bacteria related to health and disease.
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44
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Linking microbial community structure to function in representative simulated systems. Appl Environ Microbiol 2013; 79:2552-9. [PMID: 23396331 DOI: 10.1128/aem.03461-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Pathogenic bacteria are generally studied as a single strain under ideal growing conditions, although these conditions are not the norm in the environments in which pathogens typically proliferate. In this investigation, a representative microbial community along with Escherichia coli O157:H7, a model pathogen, was studied in three environments in which such a pathogen could be found: a human colon, a septic tank, and groundwater. Each of these systems was built in the lab in order to retain the physical/chemical and microbial complexity of the environments while maintaining control of the feed into the models. The microbial community in the colon was found to have a high percentage of bacteriodetes and firmicutes, while the septic tank and groundwater systems were composed mostly of proteobacteria. The introduction of E. coli O157:H7 into the simulated systems elicited a shift in the structures and phenotypic cell characteristics of the microbial communities. The fate and transport of the microbial community with E. coli O157:H7 were found to be significantly different from those of E. coli O157:H7 studied as a single isolate, suggesting that the behavior of the organism in the environment was different from that previously conceived. The findings in this study clearly suggest that to gain insight into the fate of pathogens, cells should be grown and analyzed under conditions simulating those of the environment in which the pathogens are present.
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Zakharova EE, Korneeva VA, Bryukhanov AL, Pimenov NV. A psychrophilic sulfate-reducing bacterium from the Black Sea aerobic water. Microbiology (Reading) 2012. [DOI: 10.1134/s0026261712060185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Suwannoppadol S, Ho G, Cord-Ruwisch R. Distribution of methanogenic potential in fractions of turf grass used as inoculum for the start-up of thermophilic anaerobic digestion. BIORESOURCE TECHNOLOGY 2012; 117:124-130. [PMID: 22613887 DOI: 10.1016/j.biortech.2012.04.082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 04/19/2012] [Accepted: 04/20/2012] [Indexed: 06/01/2023]
Abstract
This study aims to investigate thermophilic methanogens in turf used as an inoculum. Results showed that Methanoculleus sp. regarded as hydrogenotrophic and Methanosarcina sp. regarded as acetoclastic methanogens were present in turf tested. However, active acetoclastic methanogens were present in turf soil only. The current study showed that thermophilic methanogens were present in various turf grass species: Stenotaphrum secundatum, Cynodon dactylon, and Zoysia japonica. Severe treatments of grass leaves under oxic conditions, including blending, drying and pulverizing did not affect the thermophilic hydrogenotrophic methanogenic activity of the grass. A dried and pulverized grass extract could be generated that can serve as a readily storable methanogenic inoculum for thermophilic anaerobic digestion. The methanogens could also be physically extracted into an aqueous suspension, suitable as an inoculum. The possible contribution of the presence of methanogens on grass plants to global greenhouse emissions is briefly discussed.
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Affiliation(s)
- Suwat Suwannoppadol
- Faculty of Science & Engineering, Murdoch University, Perth, Western Australia 6150, Australia
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47
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Brioukhanov AL, Netrusov AI. The Positive Effect of Exogenous Hemin on a Resistance of Strict Anaerobic Archaeon Methanobrevibacter arboriphilus to Oxidative Stresses. Curr Microbiol 2012; 65:375-83. [DOI: 10.1007/s00284-012-0168-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Accepted: 05/31/2012] [Indexed: 11/28/2022]
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48
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Prussian Blue Modified Solid Carbon Nanorod Whisker Paste Composite Electrodes: Evaluation towards the Electroanalytical Sensing ofH2O2. INTERNATIONAL JOURNAL OF ELECTROCHEMISTRY 2012. [DOI: 10.1155/2012/238419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Metallic impurity free solid carbon nanorod “Whiskers” (SCNR Whiskers), a derivative of carbon nanotubes, are explored in the fabrication of a Prussian Blue composite electrode and critically evaluated towards the mediated electroanalytical sensing of H2O2. The sensitivity and detection limits for H2O2on the paste electrodes containing 20% (w/w) Prussian Blue, mineral oil, and carbon nanorod whiskers were explored and found to be 120 mA/(M cm2) and 4.1 μM, respectively, over the concentration range 0.01 to 0.10 mM. Charge transfer constant for the 20% Prussian Blue containing SCNR Whiskers paste electrode was calculated, for the reduction of Prussian Blue to Prussian White, to reveal a value of1.8±0.2 1/s (α=0.43,N=3). Surprisingly, our studies indicate that these metallic impurity-free SCNR Whiskers, in this configuration, behave electrochemically similar to that of an electrode constructed from graphite.
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49
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Marti R, Mieszkin S, Solecki O, Pourcher AM, Hervio-Heath D, Gourmelon M. Effect of oxygen and temperature on the dynamic of the dominant bacterial populations of pig manure and on the persistence of pig-associated genetic markers, assessed in river water microcosms. J Appl Microbiol 2011; 111:1159-75. [PMID: 21854514 DOI: 10.1111/j.1365-2672.2011.05131.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aim is to evaluate the dynamic of Bacteroides-Prevotella and Bacillus-Streptococcus-Lactobacillus populations originating from pig manure and the persistence of pig-associated markers belonging to these groups according to temperature and oxygen. METHODS AND RESULTS River water was inoculated with pig manure and incubated under microaerophilic and aerobic conditions, at 4 and 20°C over 43 days. The diversity of bacterial populations was analysed by capillary electrophoresis-single-strand conformation polymorphism. The persistence of the pig-associated markers was measured by real-time PCR and compared with the survival of Escherichia coli and enterococci. Decay was characterized by the estimation of the time needed to produce a 1-log reduction (T90). The greatest changes were observed at 20°C under aerobic conditions, leading to a reduction in the diversity of the bacterial populations and in the concentrations of the Pig-1-Bac, Pig-2-Bac and Lactobacillus amylovorus markers with a T90 of 10·5, 8·1 and 17·2 days, respectively. CONCLUSIONS Oxygen and temperature were found to have a combined effect on the persistence of the pig-associated markers in river waters. SIGNIFICANCE AND IMPACT OF THE STUDY The persistence profiles of the Pig-1-Bac, Pig-2-Bac and Lact. amylovorus markers in addition to their high specificity and sensitivity support their use as relevant markers to identify pig faecal contamination in river waters.
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Affiliation(s)
- R Marti
- Cemagref, UR GERE, Rennes, France
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50
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Functionally redundant cellobiose-degrading soil bacteria respond differentially to oxygen. Appl Environ Microbiol 2011; 77:6043-8. [PMID: 21742909 DOI: 10.1128/aem.00564-11] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The availability of oxygen (O(2)) in aerated (i.e., water-unsaturated) soils affects the metabolic activities of aerobic and anaerobic soil prokaryotes that degrade plant-derived saccharides. Fluctuating availabilities of O(2) were imposed on agricultural soil slurries supplemented with cellobiose. Slurries were subjected to oxic conditions (48 h), followed by an anoxic period (120 h) and a final oxic period (24 h). Redox potential was stable at 500 mV during oxic periods but decreased rapidly (within 10 h) under anoxic conditions to -330 mV. The consumption of cellobiose occurred without apparent delay at all redox potentials. The metabolic activities of seven previously identified saccharolytic family-level taxa of the investigated soil were measured with newly designed quantitative PCR assays targeting the 16S rRNA. Four taxa responded to the experimental conditions. The amounts of rRNAs of Micrococcaceae and Cellulomonadaceae (Actinobacteria) increased under oxic conditions. In contrast, the RNA contents of Clostridiaceae (cluster I, Firmicutes) and two uncultured family-level-taxa, i.e., "Cellu" and "Sphingo" (both Bacteroidetes) increased under anoxic conditions. That the degradation of cellobiose was independent of the availability of O(2) and that redox potentials decreased in response to anaerobic activities indicated that the degradation of cellobiose was linked to functionally redundant cellobiose-degrading taxa capable of altering redox conditions.
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