Two Cascade Reactions with Oleate Hydratases for the Sustainable Biosynthesis of Fatty Acid-Derived Fine Chemicals

Round 1

Reviewer 1 Report

 

Brück and coauthors herein present an interesting study about the development of two cascade reactions to transform waste oils in fine chemicals such as 10-(R)-hydroxy stearic acid and 10-keto stearic acid.

Although the results, as yields of the products, are not very impressing, the study described is very detailed and many parameters (light, impurities, pH...) have been evaluated. The article, in my opinion, deserves to be published in Catalysts.

Minor points. Figure 1: path (a) and (b) could be united, to obtain 10-keto stearic acid is only one more step than path (a). The introduction is very long, it should be a little reduced, and the authors should cite the enzymatic transformation of waste cooking oils fatty acids into (R)−10-hydroxystearic acid and its esters (Biundo A. et al. Enzyme and Microbial Technology, 2023, 163, 110164).

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

 

The manuscript conducted an informative methodology for producing interested fine chemicals. There are few comments that need to be addressed as below:

1.       The reason of adding each reference should be clearly known. Therefore, please eliminate multiple references. After that, please check the manuscript thoroughly and eliminate the lumps in the manuscript. This should be done by characterizing each reference individually and by mentioning 1 or 2 phrases per reference to show how it is different from the others and why it deserves mentioning. Multiple references are of no use for a reader and can substitute even a kind of plagiarism, as sometimes authors are using them without proper studies of all references used. In the case, each reference should be justified by it is used and at least short assessment provided. Please avoid lump reference (2 or more references together). Explain them individually.  Example for this is in the introduction section references (3,4), (1-6), (23-25), and so on.

2.        Figure 1: correct to (a) and (b), instead of (a) and (a)

3.       Abstract, please write the lipase producing microorganisms when mentioning lipase in the following sentence “The first cascade is placed “upstream” of an OH derived from Rhodococcus erythropolis (OhyRe), where a lipase is applied to hydrolyze triglycerides into free fatty acids,…”

4.       The following statement “It is reported that a reducing environment strongly enhances OH’s activity, which before has been achieved by applying specific equipment” is not understandable by its own, I suggest you merge the subsequent paragraph right after the above sentence to explain it appropriately.

5.       “The highest yield was achieved for rape seed oil with a conversion of 35% of oleic acid and the least for linseed oil with 6% (Figure 3 (a)), which is expected since it also contains the lowest amount of oleic acid amongst all oils (Table 1)” the maximum conversion obtained in this study of 35% is quite low, the authors need to consider to optimize the hydrolysis process by using different emulsifiers, different lipase producing microorganisms, different hydrolysis temperature, …etc. they may consider the previous in the upcoming work. In addition, I don’t think that the reason of the lowest conversion of 6%, is due to that linseed oil contains low amount of oleic acid compared to other studied oils as mentioned by the authors, because in that way high oleic acid sunflower oil should give the highest conversion which is not the case.

6.       In the introduction section, I suggest you cite the following relevant article when writing about the advantages of the lipase catalyzed reactions 10.1016/j.jclepro.2013.06.032

7.       I highly suggest to the authors that they plan to integrate an economic study to calculate the cost of producing 10-HSA and 10-KSA in large scale using he proposed methodology. Currently integrating techno-economic studies is of great interest as it brides the gap between research and industrialization.

 

 

Author Response

Please see attachment.

Author Response File: Author Response.pdf