Comparative Study of the Extracellular Holocellulolytic Activity of Fusarium solani and Aspergillus sp. in Corn Stover

Round 1

Reviewer 1 Report (Previous Reviewer 2)

Comments and Suggestions for Authors

This paper deals with the production of extracellular enzymes by two fungal species. The paper has been improved from the one submitted previously and is much easier to follow in its present form. In my opinion, the submitted manuscript is worthy of publication after some corrections:

1. L191-192 - values in experiment 2 should be checked again - the urea content with factor +1 should be 95 (not 35) g/L.

L 297-298, L 398-412 and L 26-27 (abstract) - these parts should be rewritten because if the results of the verification experiments have changed, the text should also be corrected.

Some typing errors occur (e.g. L129, 130, 177, 198, 342, 392)

Comments on the Quality of English Language

There are a few typos, but the English is generally good.

Author Response

Reviewer 1 of the fermentations_2814701 manuscript

The authors thank reviewer 1 for his valuable advice, suggestions and criticism so that fermentations_2814701 manuscript exhibits a better approach and better editing. The corrections are in blue in the manuscript. Likewise, by providing responses and corrections to the manuscript, we hope to meet your expectations for improving the approach and editing. At the same time, we are available for any corrections and suggestions that may improve the manuscript.

This paper deals with the production of extracellular enzymes by two fungal species. The paper has been improved from the one submitted previously and is much easier to follow in its present form. In my opinion, the submitted manuscript is worthy of publication after some corrections:

1. L191-192 - values in experiment 2 should be checked again - the urea content with factor +1 should be 95 (not 35) g/L. Response: It was done

L 297-298, L 398-412 and L 26-27 (abstract) - these parts should be rewritten because if the results of the verification experiments have changed, the text should also be corrected. Response:  It was done

Some typing errors occur (e.g. L129, 130, 177, 198, 342, 392). Response: Typing errors were corrected

Reviewer 2 Report (Previous Reviewer 1)

Comments and Suggestions for Authors

Overall, this is an interesting study. Some comments are provided for the authors' consideration. 

1. The significance of this study should be emphasized in the Introduction part. 

2. The reason why Fusarium solani and Aspergillus sp. were selected for this study?

3. How about the industrial application of these two strains for producing fungal holocellulases?

4. Figure 3 is not complete. Please revise. 

5. For the experimental data in Table 6, are there any repeated data; if so, the standard deviations should be provided.

6. "But studies with Aspergillus sp. for xylanase production in solid culture 321 are more numerous [36-48]", here there are too much reference. The authors should select the most related ones.  

Comments on the Quality of English Language

The manuscript is readable. 

Author Response

Reviewer 2 of the fermentations_2814701 manuscript

The authors thank Reviewer 2 for his valuable advice, suggestions and criticism so that fermentations_2814701 manuscript exhibits a better approach and better editing. The corrections are in blue in the manuscript. Likewise, by providing responses and corrections to the manuscript, we hope to meet your expectations for improving the approach and editing. At the same time, we are available for any corrections and suggestions that may improve the manuscript.

Overall, this is an interesting study. Some comments are provided for the authors' consideration. 

1. The significance of this study should be emphasized in the Introduction part. 

Response:

 In the introduction we have included a paragraph in which we highlight the importance of this study.

2. The reason why Fusarium solani and Aspergillus sp. were selected for this study?

Response:

In the introduction we have included a paragraph in which we highlight the reason why F. solani and Aspergillus sp. were selected for this study.

3. How about the industrial application of these two strains for producing fungal holocellulases?

 

Response:

 

Some fungi species from Fusarium and Aspergillus genera are tool that contribute to global demand for biotechnological products has increased steadily over the years. Thus, need for optimized processes and reduced costs appear as a key factor in the success of this market. A process tool of high importance is the direct or indirect use of enzymes to catalyze the generation of various substances. Now, in this study we show a fungal wild isolate that joins those recognized species of the Fusarium genus as promising sources of several enzymes for industrial applications, among others. However, to propose it as a tool for an enzymatic production process we must design its scaling process.

4. Figure 3 is not complete. Please revise. Figure 3 was improved
5. For the experimental data in Table 6, are there any repeated data; if so, the standard deviations should be provided.

Response:

The enzymatic activities reported in Table 6 are not experimental, but the result of the optimization, they are maximum theoretical activities found by the optimization model (ideal), Which is why the standard deviation was not reported

6. "But studies with Aspergillus sp. for xylanase production in solid culture 321 are more numerous [36-48]", here there are too much reference. The authors should select the most related ones.

Response:

We reduced the number of cites. This change caused a modification in the number of references and their numbering  

 

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

Comments and Suggestions for Authors

In this study, holocellulase (xylanases and cellulases) production from Fusarium solani and Aspergillus sp. with corn stover as a carbon source was compared by Box Wilson design. The manuscript is readable, and this study is meaningful. Yet, the novelty of this study is not high enough for Fermentation journal. The scientific findings are too basic. The current conclusions were too simple, which shows that this study didn't find something big or valuable. 

Comments on the Quality of English Language

The manuscript is readable. Moderate editing of English language required.

Reviewer 2 Report

Comments and Suggestions for Authors

This paper deals with the extraction of holocelulolytic enzymes from fungi. One of the fungi tested is well known for its activity in degrading lignocellulosic biomass. In general, the work is interesting and could be a useful piece of knowledge, but as it stands I cannot recommend it for publication. There are some minor and major issues that should be corrected, i.e:
- On what basis were the conditions chosen for the Box-Wilson design experiment? How could they be maintained? In particular, 1350 g/L CS with all nutrients?
- What was the reason for such low activities in the real experiments? Did the authors check the model? If the efficiency was a bit higher than 1% of the theoretical, is there something wrong with the model?
- In section 2.2. – “The reaction mixture was prepared in a total volume of 25 L, with a final concentration of 2 mM MgCl2, 200 mM Tris-HCl, pH 8.4, 500 mM KCl, and 0.2 mM each dNTP. For each reaction, 0.04 U/ L Taq 5U polymerase (Invitrogen, Carlsbad, CA, USA), 0.2 M each primer, and 1 L fungal template DNA were used.” - It is hard to believe that such large volumes were used for molecular identification...
- L156 and L169 - the abbreviations should be explained
- There are some formatting and editing errors throughout the text - the whole paper should be thoroughly revised.

Comments on the Quality of English Language

In general, the quality of the English is quite good, but there are a few places where it needs to be revised.

Reviewer 3 Report

Comments and Suggestions for Authors

The authors tried to present a paper dealing with the comparison of two producing microbial strains (fungi) with the aim of producing hydolytic enzymes from corn stover. However there are some serious flaws in the experimental set up and execution toghether with the bad presentation of the obtained results. Thus I can not recommend it for publication.

Here are my major concerns:

1. An optimisation method can not be performed for different cultivation techinques (smberged, semi-solid, and solid-state) under one experimental set up. You opitimise only one cultivation technique at a time.

2. The results in the abstract represent the results fro only one enzyme examined and not all three.

3. Working and vessel volume for the fermentations have not been defined, as well as the operating conditions (maybe they are the same as for incoulum preparation, but that neccessarily doesn't have to be the case).

4. Low values of the R² for the obtained models.

5. In table 5 the optimal CS (carbon source content) is 25 g/L and in the text and abrstract is says 350 g/L.

6. Table 6 shows that the experimental and modeled data in the validation experiments do not match. How is it a good model then?

7. Why is section 2.2. in the paper when there is no data about this in the results?