Isolation and Characterization of Bacillus velezensis from Lake Bogoria as a Potential Biocontrol of Fusarium solani in Phaseolus vulgaris L.
, Vitalis W. Wekesa 2, Justus M. Onguso 1, Eliud N. Wafula 3 and Ndinda Kavesu 1
Round 1
Reviewer 1 Report (Previous Reviewer 3)
I thank the authors for the detailed elaboration of the comments. All wishes were taken into account. It is proposed to accept the article after minor final changes.
1) There is no dot at the end of the sentence on the lines 86, 265, 285, 316, 317, 353 and 485.
2) Line 225 ends with the word "medium". Perhaps it was left by mistake?
3) Figure 1, perhaps, could be rotated 90 degrees, for easier perception? It remains at the discretion of the authors.
4) Lines 184-185. When writing chemical formulas of substances, subscripts could be used.
Author Response
Point 1: There is no dot at the end of the sentence on the lines 86, 265, 285, 316, 317, 353 and 485.
Response 1: Dots have been added on the lines 86, 265, 285, 316, 317, 353 and 485 as advised.
Point 2: Line 225 ends with the word "medium". Perhaps it was left by mistake?
Response 2: The word medium was left by mistake and has been deleted.
Point 3: Figure 1, perhaps, could be rotated 90 degrees, for easier perception? It remains at the discretion of the authors.
Response 3: Figure 1 has been rotated 90 degrees as suggested by the reviewer.
Point 4: Lines 184-185. When writing chemical formulae of substances, subscripts could be used.
Response 4: All chemical formulae of substances in line 184-185 has been implemented in the manuscript in the way to address the reviewer’s comment.
I would like to thank the reviewer for the expert review of my manuscript. The review process was fast, and suggestions and comments raised by the reviewer were appropriate and relevant to perfecting the manuscript. The responses to the comments/suggestions raised by the reviewer have been addressed.
Reviewer 2 Report (Previous Reviewer 2)
The authors have addressed most of the comments properly. There are only few following comments here.
Point 9: The authors cited [14] in the “Response to reviewers”, but in the revised manuscript they still cited [8]. Please double check.
Point 12: I understand that the same method was used by the authors for three different experiments. But the authors should avoid using the exact same sentences from a scientific writing aspect. Please be aware.
For Figures, what is the meaning of “a” and “b” above the error bar? The information should be included into the figure legends.
Author Response
Point 9: The authors cited [14] in the “Response to reviewers”, but in the revised manuscript they still cited [8]. Please double check.
Response 9: I have double checked and I realized it was a mistake on the “Response to reviewers” the corrected citation is [8] as indicated in the revised manuscript.
Point 12: I understand that the same method was used by the authors for three different experiments. But the authors should avoid using the exact same sentences from a scientific writing aspect. Please be aware.
Response 12: The changes has been implemented per the reviewer’s suggestion and the method for three experiments (Growth at different sodium chloride concentrations, Growth at various temperatures and Effect of pH on the growth of the isolates) has been rephrased.
Point 13. For Figures, what is the meaning of “a” and “b” above the error bar? The information should be included into the figure legends.
Response 13: The information on the meaning of “a” and “b” above the error bar already has been included in the figure legends. It read as follows; the different letter means significant differences according to Fisher's LSD test at P<0.05
I would like to thank the reviewer for the expert review of my manuscript. The review process was fast, and suggestions and comments raised by the reviewer were appropriate and relevant to perfecting the manuscript. The responses to the comments/suggestions raised by the reviewer have been addressed.
Please accept the responses raised by the authors about the reviewer's comments. Thank you.
Reviewer 3 Report (New Reviewer)
In this work, Wekesa et al. Brings forward the novelty of Bacillus velezensis as a potential biocontrol agent of Fusarium solani in P. vulgaris
The work is interesting and has potential industrial/agricultural application.
Title: Please capitalize F “fusarium”.
Abstract: Although it is important to summarize the work, the abstract looks to “heavy” to read, I would suggest a simplified form, the introduction of P. vulgaris is not really needed also just state the essential in materials and methods as well as the end result. Please shorten the abstract and simplify in a more fluent concise form.
Introduction:
Line 48: “Fusarium solani can infect more than 600 species of legumes.” State citation
Line 60-62: “The call for biocontrol use is due to prolonged use reduced efficacy of synthetic fungicides. They also pollute the environment, leaving toxic residues that broaden the range of resistant pathogens. “state citations.
Line 66: “Fusarium solani in Phaseolus vulgaris L” italics please
Line 69: “Fusarium solani” italics please
Introduction is missing data about other strains that act in antagonims with Fusarium solani
Introduction is missing data regarding Bacillus velezensis physiology an its metabolites [1,2], please focus primarily on the ones that affect Fusarium solani.
Materials and methods:
Line 78: “The Lake is alkaline and has a higher concentration of Na+ ….” citation needed.
Line 98: “in an isolation medium” please state what kind of media, just for future references in case someone wants to store it as in replicate the procedure stated.
2.4. Evaluation of Bacillus velezensis against Fusarium solani
Line 177: “filter-pater” paper
2.6.5. Phosphate solubilization ability
Line 225: “The presence or absence of a clear zone around the colonies was checked. medium” please clarify
Results
Are clear and I have no objections
Conclusions
Should better reflect the results. The conclusions stated are too vague and general.
Overall, a good and “clean” work, I do appreciate the clarity of methodology stated as in future works can replicate easily the work performed. I suggest only a minor revision taking in consideration the above stated.
References
11 Rabbee, M. F., Ali, M. S., Choi, J., Hwang, B. S., Jeong, S. C., & Baek, K. H. (2019). Bacillus velezensis: A Valuable Member of Bioactive Molecules within Plant Microbiomes. Molecules (Basel, Switzerland), 24(6), 1046. https://doi.org/10.3390/molecules24061046
22 Kim, Y.S., Lee, Y., Cheon, W. et al. Characterization of Bacillus velezensis AK-0 as a biocontrol agent against apple bitter rot caused by Colletotrichum gloeosporioides. Sci Rep 11, 626 (2021). https://doi.org/10.1038/s41598-020-80231-2
Author Response
I would like to thank the reviewer for the expert review of my manuscript. The review process was fast, and suggestions and comments raised by the reviewer were appropriate and relevant to perfecting the manuscript. The responses to the comments/suggestions raised by the reviewer have been addressed and are attached as a word document for your approval. Thank you
Author Response File: 
Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
After careful review of the ms entitled “Isolation and characterization of Bacillus velezensis from Lake Bogoria as potential biocontrol of fusarium solani in Phaseolus vulgaris L, I am not very pleased to recommend it for publication in Bacteria (MDPI)
I found lot of simple mistakes throughout the manuscript. The authors need to check the whole manuscript extensively for English checking, scientific names (should be in italic line 36, 39), reference format (eg. line 62, Line 79) to improve the manuscript.
To make this manuscript into a publishable format, the authors need to check this manuscript extensively. So I recommend it for major revision
Author Response
Thank you for the comments. I have adjusted the manuscript per your recommendations
Author Response File: Author Response.docx
Reviewer 2 Report
1 In abstract, the authors should reduce detailed technical information in the abstract unless it is very important for readers to understand your experimental designs and conclusions. For instance, Line18, primers; Line19, LB medium.
2 Line 21, use the full names for IAA and HCD.
3 Species name should be Italic all the time. Please read through and correct, e.g., in the title, line33, 99, 124, 230…
4 Line 29, optimum should be optical. What is the unit of 30-35?
5 It seems that having some enzymatic activities are important for being a potential biocontrol agent and that is why the authors performed the enzymatic assays. However, such background information is missing in the introduction.
6 Line 80, what buffer/medium was used for dilutions?
7 Line 82, does salt mean NaCl? Please be more specific.
8 Line 129, the percentage of.
9 Line 131, I assume it should be “The mycelial growth inhibition rate of Fusarium solani”? Please cite the original paper here.
10 Line 141, “NaOH 1 percent Na2CO3 as per the manufacturer is confusing.
11 There should be space between number and unit. Please correct it for the whole manuscript.
12 Line 143, please rephase it. And this sentence showed three times in the methods, which needs to be edited.
13 Line 162, “Isolate B20 and B30 were cultured on petri-dish containing skim milk agar as untreated control.” What is treated group then? It is a bit misleading.
14 Line 170. Does it mean plates without streaked-out bacteria were used as negative control?
15 Line 172, what is “chitin zone”?
16 Line 176, (N.A) can be removed as it is not used frequently in the manuscript?
17 Line 181, what is the meaning of “activated bacterial isolates”? Do the author just mean fresh cultured bacteria?
18 Line 186, “HCN generation is good” is very non-specific. The authors should indicate the amount or level of HCN generation.
19 Line 197, Luria-Bertani, use the full n
20 Line 198, it seems that Tryptophan 500 g/ml is a lot! Please double check.
21 Line 200, Do the author mean medium without inoculation? Please rephrase it.
22 Line 206, In triplicate
23 Line 222, it is better to use the number rather than the percentage as there are only 13 strains. And “Gram-positive” and “Gram-negative”.
24 For table 1, it would be better that the authors could give a standard or control strain to define different types of morphologies, e.g., in what size means small or large? Also, could the authors point out the rationale of comparing the morphology of the isolates? Is the information important for isolation or identification of targeted biocontrol agents, i.e. Bacillus velezensis?
25 The Figure 1, please pull it horizontally.
26 Line 240, the font is not consistent.
27 For Figure 3-5, (1) did the authors perform the experiments in triplicate? Please show the error bars for each. (2) Please re-organize the labels on the right side. The order is not consistent with the order of the plots. (3) To be more specific, please indicate maximal OD as X axis.
28 The figure legends for Figure 3-6 are too simple. Please add more information.
29 Is it possible to show the kinetics of growth (growth curve) at different condition that have been tested? The maximal OD value cannot fully support some of the conclusions that the authors have drawn, e.g., the trend of growth.
30 Is it surprising that B30 showed the decreasing of maximal OD when the pH is increasing from 5 to 8.5? Because it seems it grew better when pH>7.
31 Line 269, please rephrase “good growth”.
32 For Figure 6, do the author have the controls, e.g., strains that are known as protease-positive and -negative?
33 Do the three dots on the plate indicate three replicates? Could the authors show the results for B20 and B30 in parallel? What does it mean if the isolate is positive for the enzymatic activity?
Author Response
Thank you for the comments. I have adjusted the manuscript per the recommendations. R
Regards,
Author Response File: Author Response.docx
Reviewer 3 Report
The manuscript entitled "Isolation and characterization of Bacillus velezensis from Lake Bogoria as potential biocontrol of fusarium solani in Phaseolus vulgaris L." publishes the results of a study on the antifungal action of bacteria isolated from soda lake in Kenya. The methods were chosen competently, the work on isolation and analysis was carried out qualitatively, the study looks complete. The article is of scientific interest and there is novelty in it. However, the text needs significant revision. It is desirable to add illustrations to improve the perception of the material. It would be nice to bring the publication of quite valuable research to an acceptable level by correcting grammatical and semantic inaccuracies. It is proposed to accept the article after the necessary changes.
1) Lines 54, 58, 132, 157, 257, 280, 321, 448. The period at the end of the paragraph is missing.
2) Table 1 and Figure 6 are too shifted to the left.
3) Lines 240-243. The font in the figure caption is enlarged compared to the rest of the text.
4) The chapter 2.2 number is omitted in the numbering.
5) Instead of chapter numbers 2.4.2.1 and 2.4.2.2, one could simply write 2.4.2 and 2.4.3.
6) Line 209. Instead of 3.0, you should write 3.
7) Line 383. Table 3 has no signature.
8) Line 26. Instead of the sign ";", the sign ":" should have been put.
9) Line 27. Instead of the word "they" you could write "it" or rephrase.
10) Line 29. Instead of the phrase "optimal temperature record", the phrase "optimal temperature conditions" would be more appropriate.
11) Lines 38-39. A colloquial expression, it is desirable to improve the sentence.
12) Lines 43-44. It is indicated that the substances are "all present", but it is not indicated where they are present. The sentence is not related to the previous one in meaning, it looks like a disjointed text.
13) Line 66. Not quite correct use of the word "managing".
14) Line 83. Cultivation took place at 39.5 degrees. Why was this particular temperature chosen? After all, many bacteria are cultivated at lower temperatures. If the authors had an assumption about what kind of bacteria they are looking for, then they should have written about it earlier.
15) Line 124. It is not clear what B20 and B30 are. It should be clarified.
16) Line 130. Perhaps, instead of the word "treatment", the word "experiment" was meant.
17) In the captions to Figures 3, 4 and 5, the values of pH, concentration and temperature should be arranged strictly in order, from a smaller value to a larger one.
18) Lines 214-215. The sentence was separated by a semicolon, as a result of which it became cumbersome.
19) Figure 6, 3 picture. It is not clear how the sowing was carried out and how to explain the presence of stripes.
20) Figure 2. It is necessary to state the mutual inhibition of the fungus and the bacterium, and in the case of B20 it is possible that the fungus dominates.
21) Lines 287-288. The lake is more "warm water" than "thermophilic". It is better to rewrite the sentence.
22) Lines 296-298. The sentence is incorrect.
23) Line 311. The word "both" is used for only one lake.
24) In the chapter "discussions" there are many arguments that are not directly related to the authors' research. Perhaps this chapter could be shortened, leaving only what is necessary in it. It is advisable to build a logical chain of reasoning so that the paragraphs are connected to each other and the narrative goes sequentially, to facilitate perception.
25) It might be useful to insert a schematic drawing as an illustration in the first part of the article. Illustrations are present only in the middle, separating two large sections of text. Adding a graphical abstract at the beginning could unload the article.
Author Response
Thank you for the comments. We have adjusted the manuscript per your recommendations.
Author Response File: Author Response.docx
