Production of High-Value-Added Biomass by Saccharomyces cerevisiae Using Lignocellulosic Substrate

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

General comments

In this manuscript entitled in Production of high value-added biomass by Saccharomyces cerevisiae using lignocellulosic substrate, the authors examined the production of high value-added products from rice bran based on solid phase fermentation by Saccharomyces cerevisiae. Focusing on the compositional changes before and after fermentation, we are analyzing the relationship between the formation of each of those substances by PCA. Although this is a study on an important topic, it is overall like a working report, and the quality of the discussion needs to be improved for publication, and significant changes to the manuscript are needed.

Major comments

It is highly descriptive, and there is a lack of setting scientific questions and answering them. There have been many reports about microbial fermentations using rice bran biomass as substrate, it should be indicated which of the results presented in this manuscript are new findings compared to previous reports.

Minor comments

P2-L80: The unit "pp-1" is not very common and needs to be defined.

P4-L155: Rice bran incubated at the same temperature for the same time without inoculation with S. cerevisiae should be employed as a negative control.

Reference: Please check carefully how the references are described (e.g., italicized biological names).

Author Response

Dear Editors and Reviewers,

We would like to express our sincere gratitude for the valuable feedback and constructive suggestions provided during the review of our manuscript entitled “Production of high value-added biomass by Saccharomyces cerevisiae using lignocellulosic substrate.”

We have carefully considered all comments and have revised the manuscript accordingly. The modifications have been highlighted in red in the revised version of the manuscript.

Below we provide detailed responses to each reviewer’s comment.

 

Reviewer 1 – Comments and Responses

Major Comment 1:

“It is highly descriptive, and there is a lack of setting scientific questions and answering them. There have been many reports about microbial fermentations using rice bran biomass as substrate, it should be indicated which of the results presented in this manuscript are new findings compared to previous reports.”

Response:
We appreciate this observation. We revised the introduction and discussion to clearly highlight the novelty of our study, especially regarding the use of Saccharomyces cerevisiae in solid-state fermentation of both whole and defatted rice bran. We emphasized that most previous studies focus on liquid-state fermentation or filamentous fungi, and few address the metabolic distinctions between BRB and DRB when fermented by yeast. This clarification has been added to the introduction and discussion (highlighted in red).

 

Minor Comment 1 – P2-L80:
“The unit 'pp-1' is not very common and needs to be defined.”

Response:
We agree with the reviewer and revised the expression to a clearer and more standard unit ("% w/w"). The correction is shown in red in the methods section.

 

Minor Comment 2 – P4-L155:
“Rice bran incubated at the same temperature for the same time without inoculation with S. cerevisiae should be employed as a negative control.”

Response:
Thank you for pointing this out. As noted, we conducted negative control incubations without inoculation, and the results were similar to the initial (0 h) samples. Therefore, these were considered representative of the non-fermented control. We added this clarification to the Methods section, now included in red.

 

Minor Comment 3 – References:
“Please check carefully how the references are described (e.g., italicized biological names).”

Response:
We carefully revised all references and ensured that all biological names, such as Saccharomyces cerevisiae, are properly italicized throughout the manuscript.

 

Reviewer 2 Report

Comments and Suggestions for Authors

This work used yeast to produce value-added biomass from lignocellulosic substrate. The following questions should be solved.

1. Introduction should be improved to summarize the similar studies and show the novelty or feature of this work.
2. Table 1 and Table 2 should be mentioned in the text.
3.  As for solid-state fermentation, were other nutrients added into the media containing rice bran?
4. The reason for the decrease and increase of chemical composition and mineral content should be given. It lacks approriate explanation of the results.
5.  Additional evidence should be given for the deduced reason for the decrease of pH. 

Author Response

Dear Editors and Reviewers,

We would like to express our sincere gratitude for the valuable feedback and constructive suggestions provided during the review of our manuscript entitled “Production of high value-added biomass by Saccharomyces cerevisiae using lignocellulosic substrate.”

We have carefully considered all comments and have revised the manuscript accordingly. The modifications have been highlighted in red in the revised version of the manuscript.

Below we provide detailed responses to each reviewer’s comment.

Reviewer 2 – Comments and Responses

Comment 1:
“Introduction should be improved to summarize the similar studies and show the novelty or feature of this work.”

Response:
Thank you. We expanded the introduction to better contextualize previous work and highlight the unique aspects of our study, particularly the comparison between whole and defatted rice bran and the use of yeast under solid-state conditions. These changes are marked in red.

 

Comment 2:
“Table 1 and Table 2 should be mentioned in the text.”

Response:
We added explicit references to Table 1 and Table 2 within the text in the section on Mineral Analysis Methods, and these are now clearly indicated in red.

 

Comment 3:
“As for solid-state fermentation, were other nutrients added into the media containing rice bran?”

Response:
We clarified in the Methods section that no additional nutrients were added; only water and S. cerevisiae were used.

Comment 4:
“The reason for the decrease and increase of chemical composition and mineral content should be given. It lacks appropriate explanation of the results.”

Response:
We revised the Discussion to provide a more detailed biochemical explanation of the observed variations in chemical composition and mineral content, including references to metabolic pathways and enzyme activity. These additions are highlighted in red.

 

Comment 5:
“Additional evidence should be given for the deduced reason for the decrease of pH.”

Response:
We elaborated on the mechanisms behind the pH decrease, including the role of organic acid production during fermentation. This explanation has been included in the Discussion, now shown in red.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript was well corrected. 

I have no further comments, please.

Reviewer 2 Report

Comments and Suggestions for Authors

The comments were solved well.