Enhanced Methyl Tert-Butyl Ether Removal by Mixed Consortium: Performance and Adaptability

Round 1

Reviewer 1 Report

The manuscript entitles " Enhanced methyl tert-butyl ether removal by mixed consortium: Performance and adaptability" by Tingyu Hua, et al., explained about Methyl tert-butyl ether (MTBE) is widely used as a gasoline additive with toxicity and carcinogenicity, and has caused environmental problems around the world. Biodegradation is a promising way to remove MTBE using bacteria and through kinetic modeling. The manuscript has been written regularly with a good discussion. There are some revisions for better understanding as below:

1.    Please add the table of previous literature related to your work.

2.    In the introduction section add 3-4 previous literature indicating the limitation that you want to address in current studies.

3.    Clearly, indicate the novelty of the work in the manuscript.

4.    In figure 1. b is the reproducibility of degradation studies checked or not? Or do you take readings in replicates, if yes then add in graph.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript investigated the degradation of MTBE by mixed consortium and also evaluated the performance and adaptability. It is an interesting work. However, some conclusions were lack of evidence. Specific comments are as follows:

(1) Section 2.2 and Section 2.3: Both MSM and LB were used for degradation experiments in this work. Why chose these two medium?

(2) Section 3.1: What about the adsorption of MTBE by cells? Control experiments should be designed to confirm the contribution of degradation.

(3) Section 3.2, Line 210-211: MTBE removal was enhanced in mixed consortium at 30 mg/L, but the enhancement is not obvious at 50 mg/L.

(4) Section 3.2, Line 227-229: What is the different enzymatic systems in the three strains? It is the key mechanism for MTBE degradation. Authors should state it clear.

(5) Section 3.3, Line 293-294: No evidence was provided to support that strains could utilize dodecane and BTEX as the carbon source for growth.

(6) Statistical analyses: significance level (* or **) should be marked in Figure 1, Figure 2, Figure 3 and Figure 5.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

The research article entitled “Enhanced methyl tert-butyl ether removal by mixed consortium: Performance and adaptability” is written well, the authors have cited systematic literature studies, the results are presented and discussed in good manner. However, there are some major revisions. Therefore, I recommend the publication of the manuscript in “Applied Science” after these major revisions and changes.

1.Abstract section.: Arrange the keywords in alphabetical order.

2. What is difference between biodegradation and biosorption. By which mechanism bacteria remove methyl tert-butyl ether?

3.Most of the bacterial strains are toxic for humans and environment. How this technique is ecofriendly in such conditions?

4. What are the advantages of this method over other chemical and physical treatment/removal methods i.e adsorption, photodegradation etc?. Include a paragraph in introduction section.   
https://doi.org/10.3390/ijerph19169962

5.How Degradation efficiency (%) was calculated? There is no description in the manuscript.

6. Why mix consortium has been used instead of single culture? please mention the reason in manuscript text.

7.Why mineral salt medium containing different chemical compounds was used. Why simple growth media was not used?

8. Why removal rate decrease with increasing time?

Why degradation efficiency of consortium is maximum at 25⁰C and pH 7?

9. Why removal of methyl tert-butyl ether has not been studied at pH below 4 and pH above 10.

10. After degradation the methyl tert-butyl ether the degraded still contain degraded products or chemicals. Most of the chemicals formed are toxic. How this technique is efficient or superior over other treatment methods?.  

11. Many bacteria are mesophiles as their preferred temperature is body temperature (37ºC) so why removal of methyl tert-butyl ether is maximum at 25 ºC temperature?

12.Conclusion: The conclusive remarks are not well written and described. Write it in a more effective and scientific way.

13.What is future perspective for this research work? Include a paragraph for the interest of researchers in this field.

14.What is practical potential of this research work?. please mention in conclusions.

14. The manuscript should be revised thoroughly. There are some minor grammatical mistakes throughout the manuscript.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

This manuscript has been well revised.

Reviewer 3 Report

The authors have made changes accordingly; according to reviewer suggestions and comments manuscript entitled “Enhanced methyl tert-butyl ether removal by mixed consortium: Performance and adaptability” Now the paper has been improved and merit to publish in “Applied Science” journal.

Comments for author File: Comments.docx