Intermediates Production in Methane Oxidation Coupled with Denitrification: Current Status, Challenges, and Future Opportunities
Round 1
Reviewer 1 Report
1) About the microbial mechanism of the AME-D process, it is necessary to detail with examples the following points: Anaerobic Digestion. Interspecies Electron Transfer (IET). Electron Transfer Pathway. Extracellular Electron Transfer (EET). Methanogenesis. Filtration membrane.
2) The ANME-D (Anaerobic Methane Oxidizing-Direct) process its necessary to develop with citation: Anaerobic Methanotrophic Archaea (ANME). Syntrophic Partnership. Electron Transfer. Direct Interspecies Electron Transfer (DIET). Biochemical Pathways.
3) for Microbial community structure and intermediates of the MOD process, It's important to note that the MOD process is an active area of research, and ongoing studies continue to improve our understanding of the specific microbial community structures and intermediates associated with different halogenated compounds and environmental conditions. you can give more responsible mechanisms.
4) Understanding the MOD (Mixotrophic Organohalide-Respiring Dehalogenation) process involves studying the microbial communities, metabolic pathways, and environmental factors that influence the bioremediation of halogenated organic compounds. Several technologies are currently used, and potential advancements are being explored to enhance our understanding of the MOD process. Here are some of the current and potential technologies, which should be described: Next-Generation Sequencing (NGS), metagenomics and metatranscriptomics, Stable Isotope Probing (SIP), Transcriptomics and Proteomics Microbial Electrochemical, Technologies Advanced Imaging Techniques
1) About the microbial mechanism of the AME-D process, it is necessary to detail with examples the following points: Anaerobic Digestion. Interspecies Electron Transfer (IET). Electron Transfer Pathway. Extracellular Electron Transfer (EET). Methanogenesis. Filtration membrane.
2) The ANME-D (Anaerobic Methane Oxidizing-Direct) process its necessary to develop with citation: Anaerobic Methanotrophic Archaea (ANME). Syntrophic Partnership. Electron Transfer. Direct Interspecies Electron Transfer (DIET). Biochemical Pathways.
3) for Microbial community structure and intermediates of the MOD process, It's important to note that the MOD process is an active area of research, and ongoing studies continue to improve our understanding of the specific microbial community structures and intermediates associated with different halogenated compounds and environmental conditions. you can give more responsible mechanisms.
4) Understanding the MOD (Mixotrophic Organohalide-Respiring Dehalogenation) process involves studying the microbial communities, metabolic pathways, and environmental factors that influence the bioremediation of halogenated organic compounds. Several technologies are currently used, and potential advancements are being explored to enhance our understanding of the MOD process. Here are some of the current and potential technologies, which should be described: Next-Generation Sequencing (NGS), metagenomics and metatranscriptomics, Stable Isotope Probing (SIP), Transcriptomics and Proteomics Microbial Electrochemical, Technologies Advanced Imaging Techniques
Author Response
Please see the attachment
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Intermediates Production in Methane Oxidation Coupled with Denitrification: Current Status, Challenges, and Future Opportunities” may be an interesting read to the scientific audience. However, the MS requires major revision in overall for some below comments. Although, the author have well describes the research aim, and introduced with the current topic, however, the author should include the research gaps and motivation for this study as well.
The author has emphasized anaerobic methane oxidation. As, CO2 accounts for about 76 percent of total greenhouse gas emissions. Methane, primarily from agriculture, contributes 16 percent of greenhouse gas emissions and nitrous oxide, mostly from industry and agriculture, contributes 6 percent to global emissions. The author mentions if they are diverting the pathway to produce VFAs as well.
Although, ANME-D would lead in reduction of overall methane GWP. However, as a reviewer, I’m curious to know about the environmental toxicity and imbalance.
The authors have mentioned that “methane itself, as an abundant and cheap energy substance, can be of higher value as a fuel or converted into other liquid chemicals” However, microbial digestion of methane is still critically challenging due to low conversion yield, lack of robust strain and slow process compared to GTP technologies. Please state the significance of these parameters as well.
The author should emphasize more over aerobic methane oxidation coupled with denitrification (AME-D) and anaerobic methane oxidation coupled with denitrification (ANME-D) for methane dissimilation.
The author should describe the pathway for “Anaerobic methanotrophs (ANMEs) oxidize methane through the "reverse methanogenesis pathway", which does not require oxygen, thus improving carbon efficiency and energy efficiency. https://www.sciencedirect.com/science/article/pii/S0048969721053894 demonstrated the anaerobic fermentative products using CO2 for succinic acid production. Please follow for information.
The author should critically analyze the literature and mention the major research gaps through this with clear purpose. Provide some “methanotrophs” examples.
Conclusion should also include the possible products, which could be aimed from ANME and AME. Please include them as well. Besides, the future challenge scope should be presented separately.
CO2 as potential electron acceptor can be targeted for production of variety of chemical precursors. However, strain robustness, mechanical understanding, slow conversion are major obstacles of scale up activity.
Several research article demonstrated that fermentative homoacetogens such as Clostridium aceticum, C. thermoautotrophicum, C. thermoaceticum can utilize hydrogen as an electron donor to reduce CO2 to acetate through the acetyl-CoA pathway, resulting in lower bio-H2and acetate accumulation. https://www.sciencedirect.com/science/article/pii/S0960852422014924.
The author should avoid the repetition of text and phrases through the MS. For instance, nitrates, nitrates. Please correct them.
Methane can also be used to produce pure carbon free hydrogen, The author should follow some of the articles as below for more information and emphasize the anaerobic transformation of methane to biohydrogen, succinic acid, an acetic acid production as well. https://www.sciencedirect.com/science/article/pii/S0360319920346486 reviewed the various anaerobic microbes for production of value-added chemicals.
https://www.sciencedirect.com/science/article/pii/S0960852421019702 demonstrated tha oxidation of carbon-rich substrate such as methane, or acetate could be adopted in bio electrochemical systems to sink CH4. Please follow for more information.
Additionally, in section 4.1 the author should enrich the text with some latest examples from the year of 2022 and 2023 as well.
The author should ceh3c the citation style for text as well. For instance, THALASSO et al. [97] should be in lower case, Pease revise them.
The English of the text is well-established and explained
Author Response
Please see the attachment
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
No comment
No comment
Reviewer 2 Report
The authors have well revised the MS for given comments and the MS is not acceptable for publication.
