Although methanotrophs play a crucial role in the carbon cycle, our understanding of their ecology and metabolic properties is still partial. Methanotrophs are widely distributed in natural and artificial ecosystems such as organic-rich soils, wetlands, lakes, marine and riverine sediments, rumen, wastewater treatment plants, rice paddies and anaerobic digesters. They provide an essential ecosystem service by transforming methane, a potent enhancer of global warming, into less harmful carbon dioxide. Methanotrophs comprise of both bacterial and archaeal organisms. Early studies on methanotrophs only considered aerobic methanotrophs because initially, anaerobic oxidation of methane (AOM) by microorganisms was thought to be impossible due to the nonpolar C-H bond in the methane molecule. However, lately, several studies have shown that there are both archaeal and bacterial methanotrophs that can use electron acceptors other than oxygen for methane oxidation under anoxic conditions. The recent findings not only indicate the ecological significance of aerobic and anaerobic methanotrophs but their taxonomic and metabolic diversity among bacterial and as well archaeal domain.
Methane is one of the most critical greenhouse gases with global warming potential 28 – 36 times higher than that of CO2, in a timeframe of 100 years. In March 2020, National Oceanic & Atmospheric Administration (NOAA) reported that the atmospheric concentration of methane is 1876.4 ppb, which is 2.5-2.6 times higher than the preindustrial level. Methanotrophs have the natural capacity to mitigate the rise of atmospheric methane levels. The contribution of methanotrophs towards diminishing methane emissions is highly variable among different ecosystems. In soils, they may oxidize about 6 % of the produced methane, while in lakes, they can lessen the methane flow to the atmosphere by up to 80%. However, the diversity, biochemistry and genetic aspects of these microorganisms in the bacterial and archaeal domains still give rise to many questions that need to be answered to better mitigate methane emissions and industrial use of this natural product.
Our aim is to provide a single-window reference of recent scientific advances on methanotrophs. We envision the articles in the Research Topic to represent themes such as i) ideas on improvements of methanotrophic oxidation potential by employing molecular methods, ii) bioprocess development for production of added-value products and iii) development of “omics” tools to monitor methanotrophs activity in natural and human-made systems. Further, we hope that this Research Topic will help policymakers identify and decide on the methane mitigation strategies to be adopted on a local, national and global scale. This Research Topic excludes studies on methylotrophs.
This research topic will focus on original research papers, reviews and perspectives on:
1) Diversity of aerobic and anaerobic methanotrophs in natural and artificial ecosystems & their environmental relevance.
2) Biochemistry & Physiology of methanotrophs.
3) Genetic regulation of methane oxidation under aerobic & anaerobic conditions.
4) Environmental relevance of methane oxidation with different electron acceptors.
5) Biotechnological applications of methanotrophs.
Although methanotrophs play a crucial role in the carbon cycle, our understanding of their ecology and metabolic properties is still partial. Methanotrophs are widely distributed in natural and artificial ecosystems such as organic-rich soils, wetlands, lakes, marine and riverine sediments, rumen, wastewater treatment plants, rice paddies and anaerobic digesters. They provide an essential ecosystem service by transforming methane, a potent enhancer of global warming, into less harmful carbon dioxide. Methanotrophs comprise of both bacterial and archaeal organisms. Early studies on methanotrophs only considered aerobic methanotrophs because initially, anaerobic oxidation of methane (AOM) by microorganisms was thought to be impossible due to the nonpolar C-H bond in the methane molecule. However, lately, several studies have shown that there are both archaeal and bacterial methanotrophs that can use electron acceptors other than oxygen for methane oxidation under anoxic conditions. The recent findings not only indicate the ecological significance of aerobic and anaerobic methanotrophs but their taxonomic and metabolic diversity among bacterial and as well archaeal domain.
Methane is one of the most critical greenhouse gases with global warming potential 28 – 36 times higher than that of CO2, in a timeframe of 100 years. In March 2020, National Oceanic & Atmospheric Administration (NOAA) reported that the atmospheric concentration of methane is 1876.4 ppb, which is 2.5-2.6 times higher than the preindustrial level. Methanotrophs have the natural capacity to mitigate the rise of atmospheric methane levels. The contribution of methanotrophs towards diminishing methane emissions is highly variable among different ecosystems. In soils, they may oxidize about 6 % of the produced methane, while in lakes, they can lessen the methane flow to the atmosphere by up to 80%. However, the diversity, biochemistry and genetic aspects of these microorganisms in the bacterial and archaeal domains still give rise to many questions that need to be answered to better mitigate methane emissions and industrial use of this natural product.
Our aim is to provide a single-window reference of recent scientific advances on methanotrophs. We envision the articles in the Research Topic to represent themes such as i) ideas on improvements of methanotrophic oxidation potential by employing molecular methods, ii) bioprocess development for production of added-value products and iii) development of “omics” tools to monitor methanotrophs activity in natural and human-made systems. Further, we hope that this Research Topic will help policymakers identify and decide on the methane mitigation strategies to be adopted on a local, national and global scale. This Research Topic excludes studies on methylotrophs.
This research topic will focus on original research papers, reviews and perspectives on:
1) Diversity of aerobic and anaerobic methanotrophs in natural and artificial ecosystems & their environmental relevance.
2) Biochemistry & Physiology of methanotrophs.
3) Genetic regulation of methane oxidation under aerobic & anaerobic conditions.
4) Environmental relevance of methane oxidation with different electron acceptors.
5) Biotechnological applications of methanotrophs.
