Increasing the Nutritional Value of Camelina Meal via Trametes versicolor Solid-State Fermentation with Various Co-Substrates

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This study explores the impact of Trametes versicolor fermentation on the nutritional value of three substrates. Overall, the content aligns with the scope of fermentation research. However, the absence of key data, such as the chemical composition of the substrates before and after fermentation, particularly lignin data, leads to a lack of accuracy in analyzing and discussing the experimental data. Additionally, there are inconsistencies in the analysis of some data.

1. The authors need to list the chemical composition of feed ingredients such as WB, CAM, SH, and RH, including CP, NDF, ADF, lignin or more detailed components, so that readers can have a clearer understanding of these materials.In particular, for CAM as a protein resource, its protein content is especially important. However, the authors have only listed the amino acids and have not mentioned any information regarding protein loss. This omission will inevitably affect the application of the T. versicolor fermentation technology.

2. Figure 2

The results presented in Figure 2 are inconsistent with the authors' description. The authors state in the text that WM/CAM has a 32% dry matter loss, while SH/CAM has a 24% loss. The authors should provide the loss rate of crude protein.

3. Line 174-179, Figure 3

Why did the authors not use the van Soest method to directly measure the content of cellulose, hemicellulose, and lignin? Particularly since T. versicolor is a white-rot fungus, its greatest benefit lies in the degradation of lignin in the substrate. The authors need to present the results of lignin degradation rate, which is especially important for subsequent changes in IVDMD, as lignin degradation often plays a significant role in the enzymatic hydrolysis of the substrate.

4. Line 231

The descriptions at line 190 and line 231 are inconsistent.

5. Line 232

This result could also be due to a decrease in lignin content. Additionally, the reduction in cellulose content in the RH/CAM group is significant, yet it does not affect the total amino acid content.

6. Line 238-246

Based on the results shown in Figure 4, high pressure appears to have a greater degradation effect on glucosinolates in CAM. However, the authors' experiments were conducted after high-pressure sterilization followed by inoculation. In production, especially for large-scale processing in tons, high-pressure sterilization may not be feasible due to cost considerations. Therefore, it is uncertain whether the current results can be extrapolated to industrial applications.

7. Line 261-264

The appearance of "Table 12" in this section is perplexing. Additionally, the content at lines 262-264 should be placed in the discussion section.

8. Line 275-276

Please provide additional data on lignin and ash.

9. Line 267-268

Please confirm again, which group of white-rot fungi grew better.

10. Line 322-331

The loss rates of cellulose and hemicellulose before and after fermentation can truly reflect the degradation capability of the white-rot fungus on these components in the substrate.

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for the opportunity to read this valuable work.

Finding new plant materials for feed production or supporting the sustainability of feed production is necessary. The authors increased the feeding value of camelina meal mixed with wheat bran, soybean hulls or rice hulls via solid-state fermentation using the white rot fungus Trametes versicolor. Experiments evaluated not only the fungal growth, amino acid profiles, and structural carbohydrates but also the degradation of the anti-nutritive compounds like glucosinolates and phytate were also evaluated besides in vitro dry matter digestibility (IVDMD).

I'm sharing the original manuscript with my notes here.

Here, I will mention some of my remarks

Lane 56: „without free water”- I think there is water but low concentration. You can find in the literature that there are so-called solid-state fermentations even with high water activity.

In 2.3. Were the analytical parameters given based on dry weight? It is mentioned only for In vitro dry matter digestibility.

 

The Figures are well made. Only the marks for significant differences were missing in most cases.  

Comments for author File: Comments.pdf

Author Response

Finding new plant materials for feed production or supporting the sustainability of feed production is necessary. The authors increased the feeding value of camelina meal mixed with wheat bran, soybean hulls or rice hulls via solid-state fermentation using the white rot fungus Trametes versicolor. Experiments evaluated not only the fungal growth, amino acid profiles, and structural carbohydrates but also the degradation of the anti-nutritive compounds like glucosinolates and phytate were also evaluated besides in vitro dry matter digestibility (IVDMD).

I'm sharing the original manuscript with my notes here.

 

Response: We have corrected all the wording edits provided by this reviewer. Thanks so much. 

 

Here, I will mention some of my remarks

Lane 56: „without free water”- I think there is water but low concentration. You can find in the literature that there are so-called solid-state fermentations even with high water activity.

Response: We corrected our terminology. 

 

In 2.3. Were the analytical parameters given based on dry weight? It is mentioned only for In vitro dry matter digestibility.

Response: Yes, it is based on the dry weight. We corrected the content. 

 

The Figures are well made. Only the marks for significant differences were missing in most cases.  

Response: Corrected. Thanks so much.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

It is quite evident that the author has made considerable revisions to the manuscript, adding information that was not present in the initial draft, which has significantly enhanced the quality of the article. However, there are still some areas where the author has not made the correct revisions.

Fig.2

 The authors state in the text that WM/CAM has a 32% dry matter loss, while SH/CAM has a 24% loss. However, the data in Figure 2 show that the dry matter loss in the WM/CAM group is less than 25%. I raised this issue in my first review, and it is clear that the author did not carefully consider my comments.

Author Response

Comments: 

It is quite evident that the author has made considerable revisions to the manuscript, adding information that was not present in the initial draft, which has significantly enhanced the quality of the article. However, there are still some areas where the author has not made the correct revisions.

Fig.2

 The authors state in the text that WM/CAM has a 32% dry matter loss, while SH/CAM has a 24% loss. However, the data in Figure 2 show that the dry matter loss in the WM/CAM group is less than 25%. I raised this issue in my first review, and it is clear that the author did not carefully consider my comments.

Response:

Apologies, I thought I remembered changing it. The in-text results are incorrect and switched, it should follow Figure 2 and say that the WM/CAM dry matter loss is 24% and SH/CAM dry loss is 32%. It has been corrected on the latest version. Thank you for catching it.