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Singh AK, Nakhate SP, Gupta RK, Chavan AR, Poddar BJ, Prakash O, Shouche YS, Purohit HJ, Khardenavis AA. Mining the landfill soil metagenome for denitrifying methanotrophic taxa and validation of methane oxidation in microcosm. ENVIRONMENTAL RESEARCH 2022; 215:114199. [PMID: 36058281 DOI: 10.1016/j.envres.2022.114199] [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: 05/17/2021] [Revised: 05/21/2022] [Accepted: 08/20/2022] [Indexed: 06/15/2023]
Abstract
In the present study, the microbial community residing at different depths of the landfill was characterized to assess their roles in serving as a methane sink. Physico-chemical characterization revealed the characteristic signatures of anaerobic degradation of organic matter in the bottom soil (50-60 cm) and, active process of aerobic denitrification in the top soil (0-10 cm). This was also reflected from the higher abundance of bacterial domain in the top soil metagenome represented by dominant phyla Proteobacteria and Actinobacteria which are prime decomposers of organic matter in landfill soils. The multiple fold higher relative abundances of the two most abundant genera; Streptomyces and Intrasporangium in the top soil depicted greater denitrifying taxa in top soil than the bottom soil. Amongst the aerobic methanotrophs, the genera Methylomonas, Methylococcus, Methylocella, and Methylacidiphilum were abundantly found in the top soil metagenome that were essential for oxidizing methane generated in the landfill. On the other hand, the dominance of archaeal domain represented by Methanosarcina and Methanoculleus in the bottom soil highlighted the complete anaerobic digestion of organic components via acetoclasty, carboxydotrophy, hydrogenotrophy, methylotrophy. Functional characterization revealed a higher abundance of methane monooxygenase gene in the top soil and methyl coenzyme M reductase gene in the bottom soil that correlated with the higher relative abundance of aerobic methanotrophs in the top soil while methane generation being the active process in the highly anaerobic bottom soil in the landfill. The activity dependent abundance of endogenous microbial communities in the different zones of the landfill was further validated by microcosm studies in serum bottles which established the ability of the methanotrophic community for methane metabolism in the top soil and their potential to serve as sink for methane. The study provides a better understanding about the methanotrophs in correlation with their endogenous environment, so that these bacteria can be used in resolving the environmental issues related to methane and nitrogen management at landfill site.
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Affiliation(s)
- Ashish Kumar Singh
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Suraj Prabhakarrao Nakhate
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Rakesh Kumar Gupta
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Atul Rajkumar Chavan
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Bhagyashri Jagdishprasad Poddar
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Om Prakash
- National Centre for Microbial Resource, National Centre for Cell Sciences, Pune, Maharashtra, 411007, India
| | - Yogesh S Shouche
- National Centre for Microbial Resource, National Centre for Cell Sciences, Pune, Maharashtra, 411007, India
| | - Hemant J Purohit
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Anshuman Arun Khardenavis
- Environmental Biotechnology and Genomics Division, CSIR-National Environmental Engineering Research Institute, Nehru Marg, Nagpur, 440020, Maharashtra, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
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Akberdin IR, Collins DA, Hamilton R, Oshchepkov DY, Shukla AK, Nicora CD, Nakayasu ES, Adkins JN, Kalyuzhnaya MG. Rare Earth Elements Alter Redox Balance in Methylomicrobium alcaliphilum 20Z R. Front Microbiol 2018; 9:2735. [PMID: 30542328 PMCID: PMC6277846 DOI: 10.3389/fmicb.2018.02735] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/25/2018] [Indexed: 12/25/2022] Open
Abstract
Background: Rare Earth Elements (REEs) control methanol utilization in both methane- and methanol-utilizing microbes. It has been established that the addition of REEs leads to the transcriptional repression of MxaFI-MeDH [a two-subunit methanol dehydrogenase (MeDH), calcium-dependent] and the activation of XoxF-MeDH (a one-subunit MeDH, lanthanum-dependent). Both enzymes are pyrroquinoline quinone-dependent alcohol dehydrogenases and show significant homology; however, they display different kinetic properties and substrate specificities. This study investigates the impact of the MxaFI to XoxF switch on the behavior of metabolic networks at a global scale. Results: In this study we investigated the steady-state growth of Methylomicrobium alcaliphilum 20ZR in media containing calcium (Ca) or lanthanum (La, a REE element). We found that cells supplemented with La show a higher growth rate compared to Ca-cultures; however, the efficiency of carbon conversion, estimated as biomass yield, is higher in cells grown with Ca. Three complementary global-omics approaches–RNA-seq transcriptomics, proteomics, and metabolomics–were applied to investigate the mechanisms of improved growth vs. carbon conversion. Cells grown with La showed the transcriptional activation of the xoxF gene, a homolog of the formaldehyde-activating enzyme (fae2), a putative transporter, genes for hemin-transport proteins, and nitrate reductase. In contrast, genes for mxaFI and associated cytochrome (mxaG) expression were downregulated. Proteomic profiling suggested additional adjustments of the metabolic network at the protein level, including carbon assimilation pathways, electron transport systems, and the tricarboxylic acid (TCA) cycle. Discord between gene expression and protein abundance changes points toward the possibility of post-transcriptional control of the related systems including key enzymes of the TCA cycle and a set of electron-transport carriers. Metabolomic data followed proteomics and showed the reduction of the ribulose-monophosphate (RuMP) pathway intermediates and the increase of the TCA cycle metabolites. Conclusion: Cells exposed to REEs display higher rates of growth but have lower carbon conversion efficiency compared to cells supplemented with Ca. The most plausible explanation for these physiological changes is an increased conversion of methanol into formate by XoxF-MeDH, which further stimulates methane oxidation but limits both the supply of reducing power and flux of formaldehyde into the RuMP pathway.
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Affiliation(s)
- Ilya R Akberdin
- Biology Department, Viral Information Institute, San Diego State University, San Diego, CA, United States.,Institute of Cytology and Genetics SB RAS, Novosibirsk, Russia.,Novosibirsk State University, Novosibirsk, Russia
| | - David A Collins
- Biology Department, Viral Information Institute, San Diego State University, San Diego, CA, United States
| | - Richard Hamilton
- Biology Department, Viral Information Institute, San Diego State University, San Diego, CA, United States
| | | | - Anil K Shukla
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Carrie D Nicora
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Ernesto S Nakayasu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Joshua N Adkins
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Marina G Kalyuzhnaya
- Biology Department, Viral Information Institute, San Diego State University, San Diego, CA, United States
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Bizarro C, Eide M, Hitchcock DJ, Goksøyr A, Ortiz-Zarragoitia M. Single and mixture effects of aquatic micropollutants studied in precision-cut liver slices of Atlantic cod (Gadus morhua). AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 177:395-404. [PMID: 27388235 DOI: 10.1016/j.aquatox.2016.06.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 06/10/2016] [Accepted: 06/17/2016] [Indexed: 06/06/2023]
Abstract
The low concentrations of most contaminants in the aquatic environment individually may not affect the normal function of the organisms on their own. However, when combined, complex mixtures may provoke unexpected effects even at low amounts. Selected aquatic micropollutants such as chlorpyrifos, bis-(2-ethylhexyl)-phthalate (DEHP), perfluorooctanoic acid (PFOA) and 17α-ethinylestradiol (EE2) were tested singly and in mixtures at nM to μM concentrations using precision-cut liver slices (PCLS) of Atlantic cod (Gadus morhua). Fish liver is a target organ for contaminants due to its crucial role in detoxification processes. In order to understand the effects on distinct key liver metabolic pathways, transcription levels of various genes were measured, including cyp1a1 and cyp3a, involved in the metabolism of organic compounds, including toxic ones, and the catabolism of bile acids and steroid hormones; cyp7a1, fabp and hmg-CoA, involved in lipid and cholesterol homeostasis; cyp24a1, involved in vitamin D metabolism; and vtg, a key gene in xenoestrogenic response. Only EE2 had significant effects on gene expression in cod liver slices when exposed singly at the concentrations tested. However, when exposed in combinations, effects not detected in single exposure conditions arose, suggesting complex interactions between studied pollutants that could not be predicted from the results of individual exposure scenarios. Thus, the present work highlights the importance of assessing mixtures when describing the toxic effects of micropollutants to fish liver metabolism.
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Affiliation(s)
- Cristina Bizarro
- Dept. Zoology and Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Basque Country Spain
| | - Marta Eide
- Dept. of Biology, University of Bergen, N-5020 Bergen, Norway
| | - Daniel J Hitchcock
- Dept. of Biology, University of Bergen, N-5020 Bergen, Norway; Dept.of Biosciences, University of Oslo, N-0316 Oslo, Norway
| | - Anders Goksøyr
- Dept. of Biology, University of Bergen, N-5020 Bergen, Norway
| | - Maren Ortiz-Zarragoitia
- Dept. Zoology and Cell Biology, Faculty of Science and Technology and Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Basque Country Spain.
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