Evaluation of Laminaria Digitata Hydrolysate for the Production of Bioethanol and Butanol by Fermentation

Round 1

Reviewer 1 Report

The manuscript: Evaluation of Laminaria digitata hydrolysate for the production of bioethanol and butanol by fermentation an interesting topic, that describes the production of ethanol and butanol from macroalgae biomass. The results are interesting and add an important complement to the existing literature on the production of fermentable sugars and biofuels. However, there are details that should be considered.

- The title reflects the contents of the article.

- The article has level of originality.  

- Abstract - The author fails to emphasize the novelty and significance of the study. It should be improved. 

- The introduction is short, they must deeper into the subject on macroalgae conversion in terms of biorefinery concept for biofuels production: https://doi.org/10.1016/j.rser.2021.111553

- The authors could compare the results with recent works, and see perspectives in the application of macroalgae biomass in case the authors consider pertinent.: https://doi.org/10.1016/j.biortech.2021.124935, https://doi.org/10.1016/j.biortech.2022.128448

- In general terms the manuscript is well discussed.

- The graphs, tables and conclusions are adequate

I hope that these results help to improve the manuscript

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript deals with the first attempts to utilize the hydrolyzate from Laminaria digitata. Yields and concentrations reached are low, however,  possible attitudes for their direct utilization are indicated.

Prior to publication, more precise text control should be performed, there are a few apparent typing errors and nonsense sentences: L193, L184, L221-222, L484.

I also have the following comments and recommendations:

Text in lines L361 – 363 is not true. The authors did not consider higher acid production.

The description of calculations is confusing and provided many times in different forms (formulas, info in table 1 title, something is written in main text...). Information about calculations should be more transparent and provided in materials and methods.

More information should be provided:

•             for inoculation – line 122, 1g/L of biomass? How was it determined?

•             for sonication L228

I would also recommend using monosaccharides instead of monosugars and the same applies to oligosaccharides, especially triose is confusing as it is a name for c3 carbohydrate and not trisaccharide.

I did not understand the differences between experiments for which results are in tables I and II. If they were the same, one table would be much better. If they are different, please describe them more clearly.

L459 – personal communication among the authors is expected and there is no need to mention it in the text, if results are not included, add „data not shown“ instead of communication with Ana.

 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf