Bioprospecting for a Wild Strain of Sporisorium scitamineum for the Valorization of Sugarcane Molasses into Mannosylerythritol Lipids and Cellobiose Lipids

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript entitles “Bioprospecting for a wild strain of S. scitamineum for the valorization of sugarcane molasses into mannosylerythritol lipids and cellobiose lipids” is of great interest due to (i) novel wild strain of Sporisorium scitamineum for glycolipid (MEL & CBL) production using sugarcane molasses, (ii) emphasizes bioprospecting and valorization of agro-industrial waste, contributing to circular bioeconomy strategies, (iii) includes rigorous experimental work covering molecular identification, optimization, and quantification of biosurfactants, and last but important that authors achieves the highest reported CBL titer (1.46 g/L) from an industrial waste to date, which is a significant contribution. The manuscript is suitable for the Fermentation-MDPI, but requires minor revision with emphasis on improving clarity and conciseness, better figure presentation, and language and formatting corrections. Details are given below. 

• Sporisorium scitamineum is a novel fungal strain. Add full name into the title.
• The Introduction and Discussion are excessively long and repetitive, especially in justifying the use of S. citamineum and sugarcane waste. The same literature and concepts are discussed multiple times across different sections (e.g., role of sucrose, CBL vs MEL, previous studies). Condense repetitive explanations and merge related ideas for conciseness.
• S. citamineum must be italic throughout the manuscript.
• Line 122-123: Why are Scientific names underlined?
• Tables 1 & 2: Values are presented after getting results in a single run. It is recommended to provide average±SD values in the table. Also, compared your results with other fungal species for comparative analysis.
• Figure 5 and 6 interpretations (e.g., glycolipid yield trends) are largely descriptive, without statistical analysis (e.g., SD, ANOVA).
• No error bars or statistical significance reported in tables or figures, reducing reliability.
• Although the manuscript highlights biosynthesis pathways, no actual genetic/metabolic profiling (e.g., gene expression, enzyme assays) of the strain is provided. At least propose them as future directions.

Comments on the Quality of English Language

Professional English language editing is necessary for this manuscript. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Dear Authors,

The research you present constitutes a significant advancement in the biotechnological field through the use of the S. scitamineum strain. Nevertheless, I would like to offer some suggestions to further enhance the quality of the manuscript.

Title: Consider summarizing the title to make it more concise and focused.

Introduction:

• Aim for greater conciseness.

• Provide a comparative analysis of different strains that exhibit similar properties and potential, preferably in the form of a table, and clearly highlight how this particular strain stands out.

• More explicitly identify the existing knowledge gaps in the introduction and reinforce in the conclusion how these gaps were effectively addressed by your research.

Please include a scale bar in Figure 4.

Discussion: Strengthen the discussion regarding the yield analyses to provide a more comprehensive interpretation of the results.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

In this study, the authors utilize sugarcane molasses as a carbon source for the production of biosurfactants. The study utilizes a wild strain of fungi that causes sugarcane smut disease. The introduction is thorough and does a good job justifying the nature of the study and contextualizing it relative to other literature. In general, the data presentation is sound, and the conclusions follow from the analyses and results that are given. This work represents a practical contribution to valorization of the whole plant, including waste as potential feedstocks, for sugarcane processing. Please see below for some minor remarks:

Very minor comment: Please check for correct usage of superscript font, for example, in lines 231-233 for NMR description.

Figure 5 (and Figure 6) is a little bit difficult to read, it may be beneficial to rearrange this figure such that the sub-plots are presented larger in a vertical orientation (rather than horizontally arranged as currently). Please also consider enlarging the marker size to more easily distinguish between the shapes.

It may be beneficial to include the sugar composition of the molasses utilized (or if that is not available, to include sugar composition of typical molasses samples). At the very least, it would be helpful report Brix. This could also be included briefly somewhere with Table 2.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors,

Your paper entitled „Bioprospecting for a wild strain of S. scitamineum for the valorization of sugarcane molasses into mannosylerythritol lipids and cellobiose lipids“ presents very interesting work in the field of usage of new fungal strain that can produce different biosufactants like MELs and CBLs, from byproducts of sugar processing industry with potential to eventually be applied in bigger scale.

 

However, there are certain issues that need to be addressed:

General comment:

M&M section needs to be improved so that all aspects of medium preparation, cultivation conditions and analytical part are clear.

Results and Discussion section needs to be strengthened by adding more references for comparison. There is no data or supplementary data presented for LC-MS and NMR data mentioned in M&M section. For parameters calculated in tables 1 and 2, formulas should be given in section M&M. Figures should be improved.

 

L2 please put the name of the microorganism in italic

L92-102 please rewrite, there is to much text here that should be part of M&M section (especially the part that explains how wad the strain of S. scitamineum obtained)

L106 suggestion “…in Braunschweig, Germany“ --> (Braunschweig, Germany)

L109 title is Chemicals and equipment, but there is no equipment given in this section

L121 What was the composition of molasses?

L122 name of the microorganism should be given only in italic and not underlined

L123 name of the microorganism should be given only in italic

L124-L128 please state the composition of the prepared agar media

L132 instead of tissue use term fungal biomass

L169 please rephrase, not clear

L170 what is mycological peptone? Peptone isn’t found in section Chemicals and equipment

L175 NaNO₃ isn’t found in section Chemicals and equipment

L176shake flask -->flask (why use term synthetic medium? Explain pls)

L183 NaCl missing from section Chemicals and equipment Please check that all chemicals used in this work are given in section Chemicals and equipment

L185 if cultivations were performed on rotary shaker, then pH control was performed manually by adding certain amounts of phospahte-citrate buffer in what time intervals and what volume was added?

L188 -190 please rephrase becasue the medium is beeing inoculated not flask „The co-production of MELs and CBLs from sugarcane molasses was investigating by inoculating 500 mL baffled shake flasks containing 100 mL of a sugarcane molasses medium (SMM) with 1 mL seed culture“ 

L 193 was the same procedure used for GPM medium, if yes, please make corrections at line 185

L198 give preparation procedure for acidic water, and rewrite the sentence pls

L198 please give rpm rather than rcf

L333 please give figures with better resolution and connect symbols with line to ensure that reader can easily see substrate consumption, biomass growth and MEL and CBL production. Same for all pictures.

 Tables need to be improved.

 

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have significantly improved the manuscript. However, some minor updates need attention before publication. 

1. The lines in the line graph of the figures are very light in color and are difficult to understand by the readers. Kindly improve all the figures. If feasible, kindly use a dark color scheme for different factors. 
2. In tables, along with the mean value, add SD values. 

 

Author Response

Comment 1: The lines in the line graph of the figures are very light in color and are difficult to understand by the readers. Kindly improve all the figures. If feasible, kindly use a dark color scheme for different factors. 

Response 1: We improved our figures.

Comment 2: In tables, along with the mean value, add SD values. 

Response 2: We included them as a +/- in the table.

Reviewer 4 Report

Comments and Suggestions for Authors

Dear authors,

Thank you for addressing my comments.

Here are few minor corrections to your manuscript that have to be made:

L195-196 connect this sentence to the previous one

L217 missing dot at the end of sentence

L286 add software used for statistical analysis

 

For NMR and LC-MS section in M&M there are no results shown. Please give results as a part of Result section or as a supplementary info. This data would strengthen your paper.

If not, both sections should be removed from M&M section.

 

Author Response

Comment 1: L195-196 connect this sentence to the previous one

Response 1: Thank you for pointing this out. It was fixed.

Comment 2: L217 missing dot at the end of sentence

Response 2: Thank you for pointing this out. It was fixed.

Comment 3: L286 add software used for statistical analysis

Response 3: Thank you for pointing this out. We included the software used for the statistical analysis - Microsoft Excel.

Comment 4: For NMR and LC-MS section in M&M there are no results shown. Please give results as a part of Result section or as a supplementary info. This data would strengthen your paper. If not, both sections should be removed from M&M section.

Response 4: As per recommendation, we have removed these sections from the M&M section.