Broad Spectrum Antagonistic Activity of Streptomyces sp. CACIS-1.16CA Against Phytopathogenic Fungi

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study addressed an important and relevant topic in plant disease control, evaluating the broad-spectrum antifungal activity of Streptomyces sp. CACIS-1.16CA against plant pathogenic fungi. The extracellular metabolites produced by CACIS-1.16CA were tested to inhibit conidial germination. The study reports that Streptomyces sp. CACIS-1.16CA may serve as a potential natural alternative for controlling multiple plant fungal diseases. The experimental design is reasonable, and conclusions are well-supported by data from repeated experiments.

However, the Methodology section requires more detailed descriptions to ensure experimental reproducibility for other researchers. The objectives and rationale of certain experiments should be stated more clearly to better align with the overall research goals, and the connection between each set of results and the overall research question needs to be strengthened. Overall, the manuscript appears overly broad and concise in key areas, resulting in experimental content that lacks depth. In my opinion, this manuscript is not suitable for publication in this journal, or it would require substantial supplementary experiments to enhance its persuasiveness.

Author Response

Authors response:

To attend the concerns indicated by the reviewer, substantial changes to the manuscript were implemented:

1. The methods section has been modified and new details were incorporated.
2. The aims were redrafted according to the experiments
3. We modify completely the manuscript to enhance our findings related to the strain CACIS-1.16CA since we consider that this investigation highlights in important aspects that will be relevant for the readers of the journal: a) CACIS-1.16CA is substantially different to the commercial strain S. lydicus WYEC108 (used in this study) because its capacity for antagonize multiple pathogenic fungi and some phytopathogenic bacteria ( as stated in other paper cited in this manuscript); b) in vitro multiple confrontation assay against the consortia Fox-Ros-Pcap is relevant for the topic since similar information has not been cited in literature.
4. Another action that contribute to the improvement of the quality of the manuscript is that the Title of the manuscript has been modified to clarify the findings and connect more clearly with the aims of the study.

Reviewer 2 Report

Comments and Suggestions for Authors

Please refer to the attached report for all detailed comments

Comments for author File: Comments.pdf

Author Response

Comment 1

Authors response 1: The abstract was completely redrafted and modified

 Comment 2

Authors response: The phrases was modified to clarify the ideas and corrected the grammatical errors.

Comment 3

Authors response: The method is properly cited and the modification was explained

Comment 4.

Authors response: All the references in text has been corrected as journal styles.

Comment 5

Authors response: The correct name was changed and the text was corrected

• In the same section line 174 remove 3 30-min

Comment 6

Authors response: The text was rephrased as suggestion

Comment 7

Authors response: The paragraph was restructured to clarify the idea

Comment 8

Authors response: The results for SEM was integrated in results section.

Comment 9

Authors response: The 15 % of BE concentration was selected by previous experiments not included in the manuscript, wherein a test of seed germination of various vegetables was implemented to know about the toxicity on plants, specially in the process of germination. This justification is now mentioned in the text

Comment 10

Authors response: Information about the use of methanol for metabolites extraction was included

Major decision

Authors response: To improve the relevance of the manuscript for the readers an amended title was incorporated, this new title focused to the aims and include the action of the antifungal metabolites. The paper has been restructured and subject to an English revision. New information on discussion section is now included.

Reviewer 3 Report

Comments and Suggestions for Authors

The present study, "Bioactive metabolites of Streptomyces sp. CACIS-1.16CA display broad-spectrum antifungal activity against diverse phyto-pathogenic fungi " by Vargas-Gómez et al studied the evaluated the broad-spectrum antifungal activity of Streptomyces sp. CACIS-1.16CA against plant pathogenic fungi. Overall, the work is highly significant; however, has few concerns that need to be addressed before further processing of this manuscript.

Abstract
1. Please rewrite the abstract with a clear objective and outcome
2. The statement is not required "and extracellular metabolites produced by CACIS-1.16CA was tested to inhibit the conidial germination."
   similarly "An antagonist evaluation with S. lydicus WYEC108 was included as control." not required
3. What kind of conidial germination?

Introduction
4. correct the citation format
5. Add citation for the statement "Streptomyces sp. CACIS-1.16CA produces a yellow diffusible metabolite which exhibit inhibitory activity on the mycelium growth of fungal pathogens"
6. There are several statement having less scientific significance for eg line 50 "which has been focused on the production of fruits and vegetables free of harmful chemicals" is not required.
7. Line 538: Please write the Genus name in italic
8. Write the accession number of the raw sequencing data. It must be publicly available before publish the manuscript.
9. Please write the objective.
   line 93-94: The fungal strain Streptomyces sp. CACIS-1.16CA  is well known for its  antifungal activity as per line 84-85 Evangelista-Martínez, 2014. Why do you repeat the study line 92-95

Materials and Methods
10. line 98: How did you obtain these fungal strains. please write in line 99
11. Shift the table 1 in the result section

Result and discussion
12. The antifungal activity of Streptomyces sp. CACIS-1.16CA was compared with S. lydicus WYEC in this work. However, comparing with other strains could improve the discussion.
13. Although the mechanisms are not studied, but adding the possible mechanisms by including reports from other similar fungal strain will add value in this manuscript.
15. Please write the limitations of this study including the possible risks associated with the field application of Streptomyces sp. CACIS-1.16CA.

 

Comments on the Quality of English Language

The English could be improved to more clearly express the research.

Author Response

Abstract

Authors response:

1-3. The abstract was amended as suggested.

Introduction

Authors response:

4. The citation format was adjusted as indicated
5. Citation was included
6. The phrase was removed
7. Italics for the name is ready
8. The accession number of the strain was previously cited in Evangelista-Martínez. 2014.
9. The aims was redrafted

Materials and Methods

Authors response:

10. The fungal was isolated and identified in previous work of our group. The references was included.
11. Table 1 was incorporated to results section

Result and discussion

Authors response:

12. S lydicus is an excellent reference to make a comparison since the strain is the bacteria incorporated in the commercial product ACTINOVATE. Other strains were incorporated in the discussion
13. The information about the mechanisms in now discussed.

Other actions to improve the manuscript are:

1. Modification of the title of the work to concur with the aims of the work
2. Improvements in methods section, result section, and discussion section
3. English language was corrected at all the document

Reviewer 4 Report

Comments and Suggestions for Authors

Review of the article by Vargas-Gómez et al. Bioactive metabolites of Streptomyces sp. CACIS-1.16CA display broad-spectrum antifungal activity against diverse phytopathogenic fungi

General remarks. The reviewed work is devoted to the study of competitive relationships between bacteria and phytopathogenic fungi on the example of the CACIS-1.16CA strain of Streptomyces sp. and Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani. These studies are interesting both from a scientific point of view, since their data reveal some important aspects of competitive relationships between bacteria and fungi, and from a practical point of view for the development of biological methods for combating phytopathogenic fungi. Therefore, this work will undoubtedly be of interest to specialists working in the field of both fundamental and applied microbiology.

 

Detail remarks. The structure of the manuscript as a whole fully corresponds to its stated objectives and is based on a sufficient number of original materials obtained using known, proven methods. However, a number of questions and comments arise during the analysis of the manuscript. 1. On page 3 at the beginning of the Materials and Methods section, the authors provide Table 1, which presents the results of the study: Percentage of inhibition (PI) of fungal growth by Streptomyces sp. CACIS-1,16CA. This in itself is surprising, but it is also surprising that the materials of this table are discussed only on page 5 in the Results section; I believe that the table should be placed in this section. 2. In the text, the authors and year of the cited works are first indicated in parentheses, and then the numbers of these works in the list are indicated in square brackets. Most likely, there is a technical error here - the authors of the work may have forgotten to remove the references in parentheses. Another citation can be seen on page 4, line 144: Córdova-Dávalos et al. [20]. 3. In Figure 2, the captions are clearly mixed up: a) Percentage of inhibition (PI) of P. capsici (Pc), 216 F. oxysporum (Fo) and R. solani (Rs); media values with the same letter showed non-statistical difference (P > 0.05). b) Inhibitory effect on mycelium fungal growth after 7 days of incubation. In fact, a is b, and b is a! 4. Figure 3, the photos are very small, they should be given in a different scale, and the histogram is presented without the results of statistical processing. 5. Figure 4, the same thing: the photos are very small, they should be given in a different scale, and the histogram is presented without the results of statistical processing. 6. Figure 5 is clearly out of place, absolutely uninformative, remove it. 7. The Discussion section is an overview of publications, but I did not find a discussion of the author's data! 8. The conclusion is written very briefly - only two sentences, where it is said that Streptomyces sp. CACIS-1.16CA display broad-spectrum antifungal activity against diverse phytopathogenic fungi. Is that all!? It is necessary to more fully reflect the main results of the study in the conclusion.

 

Review of the article by Vargas-Gómez et al. Bioactive metabolites of Streptomyces sp. CACIS-1.16CA display broad-spectrum antifungal activity against diverse phytopathogenic fungi

General remarks. The reviewed work is devoted to the study of competitive relationships between bacteria and phytopathogenic fungi on the example of the CACIS-1.16CA strain of Streptomyces sp. and Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani. These studies are interesting both from a scientific point of view, since their data reveal some important aspects of competitive relationships between bacteria and fungi, and from a practical point of view for the development of biological methods for combating phytopathogenic fungi. Therefore, this work will undoubtedly be of interest to specialists working in the field of both fundamental and applied microbiology.

 

Detail remarks. The structure of the manuscript as a whole fully corresponds to its stated objectives and is based on a sufficient number of original materials obtained using known, proven methods. However, a number of questions and comments arise during the analysis of the manuscript. 1. On page 3 at the beginning of the Materials and Methods section, the authors provide Table 1, which presents the results of the study: Percentage of inhibition (PI) of fungal growth by Streptomyces sp. CACIS-1,16CA. This in itself is surprising, but it is also surprising that the materials of this table are discussed only on page 5 in the Results section; I believe that the table should be placed in this section. 2. In the text, the authors and year of the cited works are first indicated in parentheses, and then the numbers of these works in the list are indicated in square brackets. Most likely, there is a technical error here - the authors of the work may have forgotten to remove the references in parentheses. Another citation can be seen on page 4, line 144: Córdova-Dávalos et al. [20]. 3. In Figure 2, the captions are clearly mixed up: a) Percentage of inhibition (PI) of P. capsici (Pc), 216 F. oxysporum (Fo) and R. solani (Rs); media values with the same letter showed non-statistical difference (P > 0.05). b) Inhibitory effect on mycelium fungal growth after 7 days of incubation. In fact, a is b, and b is a! 4. Figure 3, the photos are very small, they should be given in a different scale, and the histogram is presented without the results of statistical processing. 5. Figure 4, the same thing: the photos are very small, they should be given in a different scale, and the histogram is presented without the results of statistical processing. 6. Figure 5 is clearly out of place, absolutely uninformative, remove it. 7. The Discussion section is an overview of publications, but I did not find a discussion of the author's data! 8. The conclusion is written very briefly - only two sentences, where it is said that Streptomyces sp. CACIS-1.16CA display broad-spectrum antifungal activity against diverse phytopathogenic fungi. Is that all!? It is necessary to more fully reflect the main results of the study in the conclusion.

 I believe that the manuscript can be accepted for publication after the authors take into account the comments made.

 

 

 

 

 

 

Author Response

1. Authors response:

The Table 1 was changed to results section

2. Authors response:

The style of references cited in text was adjusted as journal indications

3. Authors response:

The caption was amended

4. Authors response:

The images were improved and the statistical difference indicated in the histogram

5. Authors response:

The images were improved and the statistical difference indicated in the histogram and in the figure caption

6. Authors response:

The figure was removed and located at results section

7. Authors response:

New information was included in the discussion section and comparison with the result is now mentioned

8. Authors response:

The conclusion is modified as suggested

General comments

The title of the manuscript has been modified in order to coincide with the aims of the present work and the manuscript was completely modified to clarify all the sections.

English grammar was completely revised by experts in this field