Use of Alcaligenes faecalis to Reduce Coliforms and Enhance the Stabilization of Faecal Sludge
Round 1
Reviewer 1 Report
As noted by the authors, disposal of fecal sludge is a serious problem. Its use requires appropriate research. Most often, fecal sludge is used for agricultural purposes, after prior stabilization and removal of Escherichia coli, Salmonella, fecal streptococci, staphylococci and helminth eggs. There are various chemical and biological methods to reduce the fecal infectious population, which has its advantages and disadvantages. So far known methods include the addition of ammonia, lime or lactic acid. The authors of the article used the bacterial strain Alcaligenes faecalis DOS7, where the aim of the study was to investigate the antagonistic properties of A. faecalis against various groups of microorganisms, including coliform bacteria, and to assess the possibility of using A. faecalis to improve the effectiveness of FS treatment and reduce its infectious potential. The research is an interesting novelty. The A. faecalis strain used is not pathogenic to humans and animals and showed resistance to CHAS and PGMG biocides. This method is fast and environmentally friendly, converting fecal sludge into a safe agricultural fertilizer. The research carried out in pilot conditions may have practical application at the industrial level. As the authors noted, the use of A. faecalis bacteria in the disposal of fecal sludge and then adding it to the soil may also have a beneficial effect on plants, accelerating their growth. I believe that the article and the proposed solutions have an innovative approach. It is another method of faecal sludge disposal that requires further research.
The article is very interesting, bringing and systematizing the current information. The messages it contains are still relevant and of interest to the scientific community.
The article is clear and relevant to the field. Most of the literature cited is current from the last 5 years. Literature relevant to the topic. Figures and tables are clear, understandable and easy to interpret. Summary and conclusions appropriate and consistent.
Author Response
We sincerely thank the reviewer for his positive response
Reviewer 2 Report
Here are fews comments for author.
1. The abstract part lacks novelty, and some parts are challenging to understand. Consult some good publications and rephrase the whole section.
2. In the abstract, before concluding, mention some result-oriented key figures/facts about the importance and efficiency of your study.
3. Overall Introduction part lacks consistency: make a story link with your objectives and add more references.
4. The first two paragraphs of the introduction are not interlinked, need to add more information and references in this section.
5. Considering the different treatment methods discussed, assess the overall cost, time, and efficiency of processing faces into high-quality agricultural fertilizers. What are the key factors that need to be considered in choosing an appropriate faces treatment approach for agricultural use? Add more detail regarding these in introduction part.
6. The passage mentions that the acidic pH resulting from the proposed method can have negative effects on the soil after application. Discuss potential drawbacks or limitations of the A. faecalis DOS7 method and suggest possible solutions or improvements to address these issues.
7. Use abbreviations properly in the whole manuscript.
8. Make a more precise result and discussion section, compare your study with previous studies and compile your results carefully.
9. Be consistent with abbreviations; provide the complete form at first, and the abbreviation can be used subsequently.
10. Provide proper SI unit while quoting results.
11. The discussion part needs the latest references and emphasizes information regarding your study.
Moderate english improvement required
Author Response
We thank the reviewer for careful and and critical assessment of our work. Below are our responses point by point:
- The abstract part lacks novelty, and some parts are challenging to understand. Consult some good publications and rephrase the whole section.
Response: We have rewritten the abstract
- In the abstract, before concluding, mention some result-oriented key figures/facts about the importance and efficiency of your study.
Response: We have added more facts
- Overall Introduction part lacks consistency: make a story link with your objectives and add more references.
Response: We made some changes in the Introduction Section
- The first two paragraphs of the introduction are not interlinked, need to add more information and references in this section.
Response: We have revised the first two paragraphs
- Considering the different treatment methods discussed, assess the overall cost, time, and efficiency of processing faces into high-quality agricultural fertilizers. What are the key factors that need to be considered in choosing an appropriate faces treatment approach for agricultural use? Add more detail regarding these in introduction part.
Response: It is not possible to estimate the total cost, time and efficiency of pretreatment of FS by different methods. It will depend on the conditions in the area where it will be applied. Also the cost will depend on the characteristics of the FS in each case. There is no data in the literature on the cost of the proposed FS pretreatment methods. In the introduction section, we have summarized the information known from the literature about the different FS pretreatment methods, their advantages and disadvantages. Based on this information, we can evaluate the merits of the FS pretreatment method we are developing. Calculation of production cost and other parameters of application of this or that method should be done having a specific task. This was not included in the objectives of our study.
We have added this aspect to the end of the Discussion section.
- The passage mentions that the acidic pH resulting from the proposed method can have negative effects on the soil after application. Discuss potential drawbacks or limitations of the A. faecalis DOS7 method and suggest possible solutions or improvements to address these issues.
Response: Application of our method, on the contrary, does not lead to acidification of FS. This is its advantage over fermentation of FS with lactic acid bacteria. This is what is noted in the introduction.
- Use abbreviations properly in the whole manuscript.
Response: Abbreviations are now used properly
- Make a more precise result and discussion section, compare your study with previous studies and compile your results carefully.
Response: We have improved the results and discussion sections. In addition, appropriate statistical analysis (one-way ANOVA and Tukey's post hoc test) was performed to compare the significance of differences between treatments.
- Be consistent with abbreviations; provide the complete form at first, and the abbreviation can be used subsequently.
Response: We agree with the reviewer that this is common practice in some other journals/publishers. But this is not the case for mdpi journals. That is why we carefully checked the abbreviations throughout the text, defining them the first time they were used.
- Provide proper SI unit while quoting results.
Response: Provided
- The discussion part needs the latest references and emphasizes information regarding your study.
Response: The discussion section was modified.
Reviewer 3 Report
Present work Use of Alcaligenes faecalis to reduce coliforms and enhance stabilization of faecal sludge provide interesting information regarding microbiology and sludge management. The following edits are recommended:
Data description is very poor with no details of tabular data explanation (as what it depicts), detail of statistical design and significance of data. Without proper syatistical approach, its difficult to screen significant outcome. Please use an appropriate statistical design and post hoc test, as well as describe properly in captions of tables what data depicts (mean plus SD or SE).
English can be improved.
Author Response
Present work Use of Alcaligenes faecalis to reduce coliforms and enhance stabilization of faecal sludge provide interesting information regarding microbiology and sludge management. The following edits are recommended:
Response: We thank the reviewer for the positive assessment of our work.
Data description is very poor with no details of tabular data explanation (as what it depicts), detail of statistical design and significance of data. Without proper syatistical approach, its difficult to screen significant outcome. Please use an appropriate statistical design and post hoc test, as well as describe properly in captions of tables what data depicts (mean plus SD or SE).
Response: Details of the statistical design and significance of the data have now been added to Section 2.10. The tables and their descriptions have been modified to account for statistically significant differences between treatments as a result of one-way analysis of variance and Tukey's post hoc tests.
Reviewer 4 Report
General comments: This study aims to study the antagonistic properties of A. faecalis against various groups of microorganisms, including coliform bacteria and to evaluate the feasibility of using A. faecalis for improving the efficiency of FS treatment and reducing its infectious potential. After carefully reading, the topic of this manuscript is interesting and contains some novel results. However, the following comments must be addressed to improve the manuscript.
Specific comments:
(1) Abstract and conclusions sections: The two sections should be rewritten to make them more informative, e.g., using more quantitative data.
(2) Table 1: It is necessary to explain the meaning of “±” and the numbers behind it as a note. Please also supplement the information for other tables.
(3) Results (Tables 3-5): The manuscript will be significantly improved if the authors supplement the differences between treatments using letters (e.g., a, b, c, …) where different letters mean significant difference at P < 0.05.
(4) The statements in full text should be written in the passive voice, please revise them.
Moderate editing of English language is required.
Author Response
General comments: This study aims to study the antagonistic properties of A. faecalis against various groups of microorganisms, including coliform bacteria and to evaluate the feasibility of using A. faecalis for improving the efficiency of FS treatment and reducing its infectious potential. After carefully reading, the topic of this manuscript is interesting and contains some novel results. However, the following comments must be addressed to improve the manuscript.
Response: We thank the reviewer for the positive assessment of our work.
Specific comments:
(1) Abstract and conclusions sections: The two sections should be rewritten to make them more informative, e.g., using more quantitative data.
Response: The sections "Abstract" and "Conclusions" have been modified with the addition of quantitative data.
(2) Table 1: It is necessary to explain the meaning of “±” and the numbers behind it as a note. Please also supplement the information for other tables.
Response: Done
(3) Results (Tables 3-5): The manuscript will be significantly improved if the authors supplement the differences between treatments using letters (e.g., a, b, c, …) where different letters mean significant difference at P < 0.05.
Response: The tables and their descriptions have been modified to account for statistically significant differences between treatments as a result of one-way analysis of variance and Tukey's post hoc tests. Different letters have also been added to show significant difference between the treatments.
(4) The statements in full text should be written in the passive voice, please revise them.
Response: Done.
Round 2
Reviewer 3 Report
Authors have improved the version, and oka to be published.
Have a thorough read for sentences tructure.
Reviewer 4 Report
All comments have been solved by the authors of this manuscript and can be considered acceptance for publication.
