Experimental Study on the Preparation of a Highly Active Bacterial Suspension for MICP in the South China Sea

Round 1

Reviewer 1 Report

This manuscript grew bacteria using MICP technology, and investigated parameters that affect growth of bacteria. Authors compared their research to others and used up-to-date references. Methods are valid and discussions are supported by the presented results. Growing bacteria itself is not sustainable, but if growing a bacteria species that can be used for clean energy production, that is sustainability.  Wordings are not very succinct, results and discussion seem to be mixed, do authors still want a discussion session?

Here are some suggestions

(1)    Broth, media, strain, bacterial solution, bacterial suspension…, these terms are used interchangeable, causing confusion.

(2)    Line 310-315, repetitive with previous paragraph

(3)    Remove line 319-323, results are already accompanied by discussions. Do authors want to have a discussion session?

(4)    Remove 130-131, title of figure 2 already existed

(5)    Misspelling need to be fixed, for example “schematics” in line 118, improve English with more coherent sentences

(6)    Figure 3-11, remove grey lines and make numbers larger

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors have done a large amount of research.

The list of experiments and research results fully meet the goals and objectives set in the article. The presentation of the material has a correct logical and clear structure, accessible to the understanding of the reader. Tables and figures fully reflect the results obtained in the studies. The article has scientific novelty and practical significance. However, there are some technical minor errors that are recommended to be corrected

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Line. 52, chemical equation is not balanced.

Line 54, chemical equation is not balanced

 

Conductivity of urea solution was used to determine urease activity, actually, a more common method is to use urease assay. Have authors cross checked the measurements with a different method? Conductivity measurement does not seem to be very sensitive. All experiments seem do not have repeats? I don’t see the error bars in all figures, difficult to know about the reliability of measurements. If authors think replicates of experiment are not needed, please explain why.

 

In discussion session, authors did not discuss why they observed what they have observed, no rationalization. For example, how doe the activity they measure related to a well-known parameter for enzyme activity, Kcat, turn over number? Authors explain that “The effect of prolonging the shaking time on the urease activity of the broth was mainly in terms of "slowing down the decay of activities" and "promoting the increase of activities". The continued shaking of the bacterial broth will promote the maintenance of urease activity if the urease activity of the broth has reached its peak; if the urease activity of the broth has not reached its peak, extending the shaking time will promote the increase of urease activity”, could they put these words into a more scientific context, for example, urea, the substrate, there is the famous Michaelis-Menten equation which describes that above Km, enzyme activity saturates.

 

Languages are not very scientific, and detailed description sometimes hard to understand. For example, parallel groups-à control group?

Author Response

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Author Response File: Author Response.docx

Round 3

Reviewer 1 Report

may be just publish