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Ahmadi F, Lackner M. Recent findings in methanotrophs: genetics, molecular ecology, and biopotential. Appl Microbiol Biotechnol 2024; 108:60. [PMID: 38183483 DOI: 10.1007/s00253-023-12978-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 09/08/2023] [Accepted: 10/01/2023] [Indexed: 01/08/2024]
Abstract
The potential consequences for mankind could be disastrous due to global warming, which arises from an increase in the average temperature on Earth. The elevation in temperature primarily stems from the escalation in the concentration of greenhouse gases (GHG) such as CO2, CH4, and N2O within the atmosphere. Among these gases, methane (CH4) is particularly significant in driving alterations to the worldwide climate. Methanotrophic bacteria possess the distinctive ability to employ methane as both as source of carbon and energy. These bacteria show great potential as exceptional biocatalysts in advancing C1 bioconversion technology. The present review describes recent findings in methanotrophs including aerobic and anaerobic methanotroph bacteria, phenotypic characteristics, biotechnological potential, their physiology, ecology, and native multi-carbon utilizing pathways, and their molecular biology. The existing understanding of methanogenesis and methanotrophy in soil, as well as anaerobic methane oxidation and methanotrophy in temperate and extreme environments, is also covered in this discussion. New types of methanogens and communities of methanotrophic bacteria have been identified from various ecosystems and thoroughly examined for a range of biotechnological uses. Grasping the processes of methanogenesis and methanotrophy holds significant importance in the development of innovative agricultural techniques and industrial procedures that contribute to a more favorable equilibrium of GHG. This current review centers on the diversity of emerging methanogen and methanotroph species and their effects on the environment. By amalgamating advanced genetic analysis with ecological insights, this study pioneers a holistic approach to unraveling the biopotential of methanotrophs, offering unprecedented avenues for biotechnological applications. KEY POINTS: • The physiology of methanotrophic bacteria is fundamentally determined. • Native multi-carbon utilizing pathways in methanotrophic bacteria are summarized. • The genes responsible for encoding methane monooxygenase are discussed.
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Affiliation(s)
- Fatemeh Ahmadi
- School of Agriculture and Environment, University of Western Australia, Crawley, 6009, Australia
- Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Tasmania, 7001, Australia
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Zhao Y, Liu Y, Cao S, Hao Q, Liu C, Li Y. Anaerobic oxidation of methane driven by different electron acceptors: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174287. [PMID: 38945238 DOI: 10.1016/j.scitotenv.2024.174287] [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: 02/06/2024] [Revised: 05/31/2024] [Accepted: 06/23/2024] [Indexed: 07/02/2024]
Abstract
Methane, the most significant reduced form of carbon on Earth, acts as a crucial fuel and greenhouse gas. Globally, microbial methane sinks encompass both aerobic oxidation of methane (AeOM), conducted by oxygen-utilizing methanotrophs, and anaerobic oxidation of methane (AOM), performed by anaerobic methanotrophs employing various alternative electron acceptors. These electron acceptors involved in AOM include sulfate, nitrate/nitrite, humic substances, and diverse metal oxides. The known anaerobic methanotrophic pathways comprise the internal aerobic oxidation pathway found in NC10 bacteria and the reverse methanogenesis pathway utilized by anaerobic methanotrophic archaea (ANME). Diverse anaerobic methanotrophs can perform AOM independently or in cooperation with symbiotic partners through several extracellular electron transfer (EET) pathways. AOM has been documented in various environments, including seafloor methane seepages, coastal wetlands, freshwater lakes, soils, and even extreme environments like hydrothermal vents. The environmental activities of AOM processes, driven by different electron acceptors, primarily depend on the energy yields, availability of electron acceptors, and environmental adaptability of methanotrophs. It has been suggested that different electron acceptors driving AOM may occur across a wider range of habitats than previously recognized. Additionally, it is proposed that methanotrophs have evolved flexible metabolic strategies to adapt to complex environmental conditions. This review primarily focuses on AOM, driven by different electron acceptors, discussing the associated reaction mechanisms and the habitats where these processes are active. Furthermore, it emphasizes the pivotal role of AOM in mitigating methane emissions.
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Affiliation(s)
- Yuewen Zhao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Yaci Liu
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
| | - Shengwei Cao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Qichen Hao
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Chunlei Liu
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China
| | - Yasong Li
- Fujian Provincial Key Laboratory of Water Cycling and Eco-Geological Processes, Xiamen 361021, China; Institute of Hydrogeology and Environmental Geology, Chinese Academy of Geological Sciences, Shijiazhuang 050061, China.
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Wen F, Biederman JA, Hao Y, Qian R, Zheng Z, Cui X, Zhao T, Xue K, Wang Y. Extreme drought alters methane uptake but not methane sink in semi-arid steppes of Inner Mongolia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 915:169834. [PMID: 38190902 DOI: 10.1016/j.scitotenv.2023.169834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/25/2023] [Accepted: 12/30/2023] [Indexed: 01/10/2024]
Abstract
Global climate change, particularly drought, is expected to alter grassland methane (CH4) oxidation, a key natural process against atmospheric greenhouse gas accumulation, yet the extent of this effect and its interaction with future atmospheric CH4 concentrations increases remains uncertain. To address this research gap, we measured CH4 flux during an imposed three-month rain-free period corresponding to a 100-year recurrence drought in soil mesocosms collected from 16 different Eurasian steppe sites. We also investigated the abundance and composition of methanotrophs. Additionally, we conducted a laboratory experiment to explore the impact of elevated CH4 concentration on the CH4 uptake capacity of grassland soil under drought conditions. We found that regardless of the type of grassland, CH4 flux was still being absorbed at its peak, meaning that all grasslands functioned as persistent CH4 sinks even when the soil water content (SWC) was <5 %. A bell-shaped relationship between SWC and CH4 uptake was observed in the soils. The average maximum CH4 oxidation rate in the meadow steppe was higher than that in the typical and desert steppe soils during extreme drought. The experimental elevation of atmospheric CH4 concentration counteracted the anticipated reduction in CH4 uptake related to physiological water stress on methanotrophic soil microbes under the drought stress. On the contrary, we found that across the regional scale, nitrogen, phosphorous, and total soil organic content played a crucial role in moderating the duration and magnitude of CH4 uptake with respect to SWC. USC-γ (Upland Soil Cluster γ) and JR-3 (Jasper Ridge Cluster) were the dominant group of soil methanotrophic bacteria in three types of grassland. However, the methanotrophic abundance, rather than the methanotrophic community composition, was the dominant microbiological factor governing CH4 uptake during the drought.
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Affiliation(s)
- Fuqi Wen
- College of Life Sciences, University Chinese Academy of Sciences, Beijing, China
| | - Joel A Biederman
- Southwest Watershed Research Center, Agricultural Research Service, Tucson, AZ, USA
| | - Yanbin Hao
- College of Life Sciences, University Chinese Academy of Sciences, Beijing, China; Yanshan Earth Critical Zone and Surface Fluxes Research Station, Chinese Academy of Sciences, Beijing 101408, China..
| | - Ruyan Qian
- College of Life Sciences, University Chinese Academy of Sciences, Beijing, China
| | - Zhenzhen Zheng
- College of Life Sciences, University Chinese Academy of Sciences, Beijing, China
| | - Xiaoyong Cui
- College of Life Sciences, University Chinese Academy of Sciences, Beijing, China; Yanshan Earth Critical Zone and Surface Fluxes Research Station, Chinese Academy of Sciences, Beijing 101408, China
| | - Tong Zhao
- School of Mathematics Sciences, University Chinese Academy of Sciences, Beijing 101408, China
| | - Kai Xue
- Yanshan Earth Critical Zone and Surface Fluxes Research Station, Chinese Academy of Sciences, Beijing 101408, China.; Key Laboratory of Adaptation and Evolution of Plateau Biota, Chinese Academy of Sciences, Xining 810001, China; College of Resources and Environment, University Chinese Academy of Sciences, Beijing 101408, China
| | - Yanfen Wang
- Yanshan Earth Critical Zone and Surface Fluxes Research Station, Chinese Academy of Sciences, Beijing 101408, China.; College of Resources and Environment, University Chinese Academy of Sciences, Beijing 101408, China
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Li L, Hu Z, Tan G, Fan J, Chen Y, Xiao Y, Wu S, Zhi Q, Liu T, Yin H, Tang Q. Enhancing plant growth in biofertilizer-amended soil through nitrogen-transforming microbial communities. FRONTIERS IN PLANT SCIENCE 2023; 14:1259853. [PMID: 38034579 PMCID: PMC10683058 DOI: 10.3389/fpls.2023.1259853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 10/13/2023] [Indexed: 12/02/2023]
Abstract
Biofertilizers have immense potential for enhancing agricultural productivity. However, there is still a need for clarification regarding the specific mechanisms through which these biofertilizers improve soil properties and stimulate plant growth. In this research, a bacterial agent was utilized to enhance plant growth and investigate the microbial modulation mechanism of soil nutrient turnover using metagenomic technology. The results demonstrated a significant increase in soil fast-acting nitrogen (by 46.7%) and fast-acting phosphorus (by 88.6%) upon application of the bacterial agent. This finding suggests that stimulated soil microbes contribute to enhanced nutrient transformation, ultimately leading to improved plant growth. Furthermore, the application of the bacterial agent had a notable impact on the accumulation of key genes involved in nitrogen cycling. Notably, it enhanced nitrification genes (amo, hao, and nar), while denitrification genes (nir and nor) showed a slight decrease. This indicates that ammonium oxidation may be the primary pathway for increasing fast-acting nitrogen in soils. Additionally, the bacterial agent influenced the composition and functional structure of the soil microbial community. Moreover, the metagenome-assembled genomes (MAGs) obtained from the soil microbial communities exhibited complementary metabolic processes, suggesting mutual nutrient exchange. These MAGs contained widely distributed and highly abundant genes encoding plant growth promotion (PGP) traits. These findings emphasize how soil microbial communities can enhance vegetation growth by increasing nutrient availability and regulating plant hormone production. This effect can be further enhanced by introducing inoculated microbial agents. In conclusion, this study provides novel insights into the mechanisms underlying the beneficial effects of biofertilizers on soil properties and plant growth. The significant increase in nutrient availability, modulation of key genes involved in nitrogen cycling, and the presence of MAGs encoding PGP traits highlight the potential of biofertilizers to improve agricultural practices. These findings have important implications for enhancing agricultural sustainability and productivity, with positive societal and environmental impacts.
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Affiliation(s)
- Liangzhi Li
- College of Plant Protection, Hunan Agricultural University, Changsha, China
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Zhengrong Hu
- Hunan Tobacco Research Institute, Changsha, China
| | - Ge Tan
- China Tobacco Hunan Industrial Co., Ltd., Changsha, China
| | - Jianqiang Fan
- Technology Center, China Tobacco Fujian Industrial Co., Ltd., Xiamen, Fujian, China
| | - Yiqiang Chen
- Technology Center, China Tobacco Fujian Industrial Co., Ltd., Xiamen, Fujian, China
| | - Yansong Xiao
- Chenzhou Tobacco Company of Hunan Province, Chenzhou, China
| | - Shaolong Wu
- Hunan Tobacco Research Institute, Changsha, China
| | - Qiqi Zhi
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Tianbo Liu
- Hunan Tobacco Research Institute, Changsha, China
| | - Huaqun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, China
| | - Qianjun Tang
- College of Plant Protection, Hunan Agricultural University, Changsha, China
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Veerasamy V, Jagannathan UM, Arakkala SD, Shafee WA, Kaliannan T. Exploring the bacterial genetic diversity and community structure of crude oil contaminated soils using microbiomics. ENVIRONMENTAL RESEARCH 2023; 236:116779. [PMID: 37517495 DOI: 10.1016/j.envres.2023.116779] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 07/08/2023] [Accepted: 07/27/2023] [Indexed: 08/01/2023]
Abstract
The impact of environmental pollution in air and water is reflected mainly in the soil ecosystem as it impairs soil functions. Also, since the soil is the habitat for billions of organisms, the biodiversity is in turn altered. Microbes are precise sensors of ecological contamination, and bacteria have a key and important function in terms of bioremediation of the contaminated soil. Hence in the current work, we aimed at assessing the unidentified bacterial population through Illumina MiSeq sequencing technology and their community structural changes in different levels of petroleum-contaminated soil and sludge samples (aged, sludge, and leakage soil) to identify unique bacteria for their potential application in remediation. The studies showed that major bacterial consortiums namely, Proteobacteria (57%), Alphaproteobacteria (31%), and Moraxellaceae (23%) were present in aged soil, whereas Proteobacteria (52%), Alphaproteobacteria (33%), and Rhodobacteraceae (28%) were dominantly found in sludge soil. In leakage soil, Proteobacteria (59%), Alphaproteobacteria (33%), and Rhodobacteraceae (29%) were abundantly present. The Venn diagrams are used to analyze the distribution of abundances in individual operational taxonomic units (OTUs) within three soil samples. After data filtering, they were grouped into OTU clusters and 329 OTUs were identified from the three soil samples. Among the 329, 160 OTUs were common in the three soil samples. The bacterial diversity is estimated using alpha diversity indices and Shanon index and was found to be 4.490, 4.073 and 4.631 in aged soil, sludge soil and leakage soil, respectively and similarly richness was found to be 618, 417 and 418. The heat map was generated by QIIME software and from the top 50 enriched genera few microbes such as Pseudomonas, Bacillus, Mycobacterium, Sphingomonas and Paracoccus, were shown across all the samples. In addition, we also analyzed various physicochemical properties of soil including pH, temperature, salinity, electrical conductivity, alkalinity, total carbon, total organic matter, nitrogen, phosphorus and potassium to calculate the soil quality index (SQI). The SQI of aged, sludge and leakage soil samples were 0.73, 0.64, and 0.89, respectively. These findings show the presence of unexplored bacterial species which could be applied for hydrocarbon remediation and further they can be exploited for the same.
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Affiliation(s)
- Veeramani Veerasamy
- Laboratory of Molecular Bioremediation and Nanobiotechnology, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Uma Maheswari Jagannathan
- Department of Civil Engineering, Priyadarshini Engineering College, Vaniyambadi, Tirupattur, 635 751, Tamil Nadu, India
| | - Sherry Davis Arakkala
- Department of Environmental Studies, A.M. Jain College, Meenambakkam, Chennai, 600 114, Tamil Nadu, India
| | - Wasim Akthar Shafee
- Laboratory of Molecular Bioremediation and Nanobiotechnology, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India
| | - Thamaraiselvi Kaliannan
- Laboratory of Molecular Bioremediation and Nanobiotechnology, Department of Environmental Biotechnology, School of Environmental Sciences, Bharathidasan University, Tiruchirappalli, 620 024, Tamil Nadu, India.
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Jiang L, Zhao Y, Yao Y, Lou J, Zhao Y, Hu B. Adding siderophores: A new strategy to reduce greenhouse gas emissions in composting. BIORESOURCE TECHNOLOGY 2023:129319. [PMID: 37315620 DOI: 10.1016/j.biortech.2023.129319] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 06/10/2023] [Accepted: 06/10/2023] [Indexed: 06/16/2023]
Abstract
Microbial community is the primary driver causing the greenhouse gas emissions in composting. Thus, regulating the microbial communities is a strategy to reduce them. Here, two different siderophores (enterobactin and putrebactin) were added, which could bind and translocate iron by specific microbes, to regulate the composting communities. The results showed that adding enterobactin enriched Acinetobacter and Bacillus with specific receptors by 6.84-fold and 6.78-fold. It promoted carbohydrate degradation and amino acid metabolism. This resulted in a 1.28-fold increase in humic acid content, as well as a 14.02% and 18.27% decrease in CO2 and CH4 emissions, respectively. Meanwhile, adding putrebactin boosted the microbial diversity by 1.21-fold and enhanced potential microbial interactions by 1.76-fold. The attenuated denitrification process led to a 1.51-fold increase in the total nitrogen content and a 27.47% reduction in N2O emissions. Overall, adding siderophores is an efficient strategy to reduce greenhouse gas emissions and promote the compost quality.
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Affiliation(s)
- Liyan Jiang
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuting Zhao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuqing Yao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Jingxuan Lou
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Yuxiang Zhao
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China
| | - Baolan Hu
- College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Environment Remediation and Ecological Health, Ministry of Education, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Water Pollution Control and Environmental Safety of Zhejiang Province, Hangzhou310058, China.
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