Review Reports
by
- Song Qiu 1,
- Luyang Wang 2 and
- Yingjie Yu 4,*
- et al.
Reviewer 1: Bhim Sen Thapa Reviewer 2: Anonymous
Round 1
Reviewer 1 Report
The paper lacks the scientific potency to stand in its present form. The design of study is completely naive. The language is very poor with the usage of inappropriate terminologies, grammar and language.
Introduction section is full of misleading statement and false assumption. The section has to be revised entirely with scientific English. For eg. MFCs are not generic devices designed according to the utilization of electrogenic microorganisms in L30-32. L46-48, target analytes in an anode chamber which could influence the output signal.......... etc.
Materials and methods: Provide complete information of materials and experiments done. What was the cathode material used, was that air cathode or anaerobic one? How was pre-inoculum cultured anaerobically? and what is the reason for doing this? remove the terms batch-loading, carbon resources, photophobic conditions, electronical, inoculation period etc. throughout the manuscript.
Polarization and power density curve analysis are done to assert the performance of a fuel cell. CV, ESI are performed for studying the electrochemical reactions of the system. What is the reason for analysis of anode biofilm (CSLM) and Metagenomics in biosensors studies?
Did authors calculated the Coulombic efficiencies from their system or tested different organic compounds apart from glucose and acetate?
Results and discussion
The CV peaks for MFC-A and MFC-B looks similar in reverse scan while on forward scan the oxidation peaks are distinct. what could be the reason?
Please follow same format for figure 2a and 2b. if they are run in triplicates or multiple sets, please give error bars on power densities curve.
The use of acetate and glucose in MFC-A and MFC-B which itself are grown on acetate and glucose is not a good idea. with this data it can be concluded that MFCs are biosensors here. They are not reliable.
All the numbers shown are without error level. are these studies conducted in a single set or just once?
What was the purpose of CSLM analysis?
Was there any significance with dominant microbes and MFC conditions in this study?
Please follow the nomenclature. bacteria must be written in Italic format.
Conclusion is not satisfactory.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
General Comments:
Overall, this paper is well organized. However, there are several concerns, which are given below.
Specific Comments:
1. Lines 16-17: It is stated that “MFC-A presented a superior performance than that of MFC-B for the test of sodium acetate (4868.9 vs. 2202 mV/(g/L)) and glucose (3895.5 vs. 3192.9 mV/(g/L)) separately.”
a) The baseline data (that shows that MFC-A and MFC-B were the same (i.e. they give the same performance) were not provided in the result section. In other words, MFC-A and MFC-B give the same results (e.g., same voltage, power density, internal resistance) if they were run under the same conditions (e.g., same substrate at the same concentration). Without the baseline data, the above statement (Lines 16-17) cannot be justified.
2. Lines 22-24: It is stated that “MFC-A delivered a higher output voltage and maximum power density (593.76 mV and 331.40 mW/m2) than that of MFC-B (484.08 mV and 297.25 mW/m2) during the inoculation period.”
a) As commented above, without the baseline data, the above statement (Lines 22-24) cannot be justified.
33. Lines 95-96: It is stated that “When the peak voltage of five consecutive cycles stayed stable, the startup of MFC was deemed successful.”
a) What were the peak voltage? Did both MFC-A and MFC-B produce the same voltage? If the peak voltage values were different between MFC-A and MFC-B, explain what caused the difference.
b) Provide the baseline data to show MFC-A and MFC-B were the same (e.g., they give the same voltage, power density, internal resistance and Coulombic efficiency, under the same conditions) or close enough to justify the comparisons made in this paper.
4. Lines 96-98: “Two MFCs were started and acclimated in this study, MFC-A with 0.5 g/L sodium acetate as inoculated carbon resource and MFC-B with 0.5 g/L glucose as inoculated carbon resource.”
aa) Since reactions are based on the number of moles (not grams), 0.5 g/L sodium acetate vs. 0.5 g/L glucose are not comparable. To make them comparable, provide the Coulombic efficiencies for the both MFC-A and MFC-B runs in the Result section.
5. Lines 142-144: “To explore the electrochemical performance of MFC sensors, the output voltage of MFC-A and MFC-B with anolyte of 0.5 g/L sodium acetate and 0.5 g/L glucose as carbon resource were monitored in the startup period.”
a) As was commented above, because chemical/biological reactions are based on the number of moles (not grams), 0.5 g/L sodium acetate vs. 0.5 g/L glucose are not comparable. To make them comparable, provide the Coulombic efficiencies for the both MFC-A and MFC-B runs.
b) As was also commented previously, it is essential to show that MFC-A and MFC-B have the same baseline so that substrate (sodium acetate vs. glucose) is the only variable.
6. The same comments apply to the rest of the comparison results.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Need improvement.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx