Indicators of the Microbial Corrosion of Steel Induced by Sulfate-Reducing Bacteria Under the Influence of Certain Drugs

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

see attached file

Comments for author File: Comments.docx

Author Response

Dear Reviewer 1,

Thank you very much for your attention to our manuscript, all comments and suggestions! They are very important to us!

We have taken into account all your remarks, corrected all mistakes and inaccuracies.

 

Namely:

1. General comments

The article deals with corrosion processes which are induced by sulfate reducing bacteria such as Desulfovibrio oryzae. For the prevention of these destructive processes compounds such as DMSO and paracetamol have been tested. It could be shown that DMSO could inhibit bacterial growth at higher concentrations and that paracetamol as a pharmaceutical drug contributed to a higher corrosion rate. The deeper sense of these investigations lies in the fact that DMSO and paracetamol present in wastewater can possibly damage steel pipes in wastewater treatment plants and these corrosion processes should be prevented.

First of all, the research topic is rather interesting and the findings deserve being published. The methodology used is rather simple, but nevertheless gave some interesting results. Furthermore, the introduction and also the discussion should be broadened to include standardized bacterial toxicity tests (see: https://doi.org/10.1007/s00253-024-13286-0) to estimate the toxicity of certain chemical compounds. There is also recent literature available which states that DMSO concentrations  above 2 % have an inhibitory effect on nitrifying bacteria in wastewater treatment plants (see: https://doi.org/10.1021/acsestwater.2c00607). Also the pharmaceutical drug paracetamol has some interesting effects in wastewater treatment plants which should also be discussed (see: https://doi.org/10.1016/j.chemosphere.2018.04.179).  Here the EC50 for paracetamol in the well established Microtox test was in the range of 8 to 9 gL^-1. For details of the applicability of Microtox for wastewater and wastewater treatment plants see recent literature (https://doi.org/10.3390/pr8111349).

I think the discussion should be broadened in this way to make the article more interesting for a wide range of readers.

Thank you for your valuable comments and recommendations. We have analyzed the suggested sources and expanded the introduction and discussion.

 

2. Some specific comments
3. 16. It should be “the pharmaceutical drug paracetamol”

We wrote as recommended.

 

Please also add the structure formulas of DMSO and paracetamol for informative purposes.

We have added structural formulas of the compounds.

 

80. 80. Please give the composition of Postgate’s “C”-medium.

We wrote the composition of the Postgate’s “C” culture medium.

 

Table 1. Why did you not perform another  assay with DMSO and paracetamol?

The aim of the work was to investigate the indicators of microbial corrosion of steel - biofilm biomass and corrosion rate, which was possible precisely under these research options.

 

1. 229 Here would be a ideal position for a further discussion of bacterial toxicity tests as indicated above.

We have added the necessary information.

 

266. 252 and 266. Please avoid too many zeros before a comma. Please use an exponential depiction of numbers.

We have corrected the spelling of the numbers.

 

1. 284 The conclusion part should be broadened taking into account the important point of bacterial toxicity.

We noted the presence of toxic properties in DMSO and their absence in paracetamol with respect to SRB.

 

All in all, I recommend a major revision taking into account the points mentioned above.

We have made changes according to the comments and added the recommended parts.

Please see our manuscript with changes according to your comments.We really hope that you will respond positively to our corrections! Thank you again for your valuable comments and suggestions! Sincerely yours,

Authors

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The paper is of high interest. I propose that   the authors also add more about the possible impact of these drugs on SRA  (sulphate reducing archaea). 

Comments on the Quality of English Language

Qulity of English  is  average and needs to be improved.

Author Response

Dear Reviewer 2,

Thank you very much for your attention to our manuscript, all comments and suggestions! They are very important to us!

We have taken into account all your remarks, corrected all mistakes and inaccuracies.

 

Namely:

The paper is of high interest. I propose that   the authors also add more about the possible impact of these drugs on SRA  (sulphate reducing archaea). 

-We have added the necessary information regarding the participation of archaea in the biodegradation processes of these drugs. However, we were unable to specifically specify sulfate-reducing archaea, as such data are not available in the available scientific database.

 

Qulity of English  is  average and needs to be improved

-The quality of the English was checked by an English teacher and all errors were corrected.

 

Please see our manuscript with changes according to your comments.We really hope that you will respond positively to our corrections! Thank you again for your valuable comments and suggestions! Sincerely yours,

Authors

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Now the article is fine and ready for publication.