Enzymatic Synthesis of Glucose Fatty Acid Esters Using SCOs as Acyl Group-Donors and Their Biological Activities
, Ahmed M. Elazzazy 3,4,†, Tamer S. Saleh 5, Marianna Dourou 6, Jazem A. Mahyoub 7, Mohammed N. Baeshen 3, Hekmat R. Madian 8 and George Aggelis 3,6,*Round 1
Reviewer 1 Report
This work studies the enzymatic synthesis of glucose fatty acid esters using single cell oils. More concretely the work studies the esterification and transesterification reactions between these oils and glucose, catalyzed by immobilized lipase Candida antarctica B.
In my opinion the work is acceptable and could be published in Applied Sciences. Only I want to do the following comments:
Page 2, line 88. Reference [36] is really the reference [35]. It would be convenient revise all the reference numbers.
Page 2, lines 92-94. The last sentence “We concluded that GEs…” seems a conclusion and this is the introduction section. Therefore it is not the more suitable place for this sentence.
Page 3, line 141 and along the article. I do not understand why the authors always write “% conversion” or “conversion %”. I think that writing “conversion” is enough. The “%” is the unit and it is not necessary to write the unit each that the word “conversion” appears.
Page 4, line 157. I think that washing the lipase with ethanol is not a good idea because it is known that short chain alcohols (methanol and ethanol) can deactivate the lipases.
Page 6, lines 224-227. In this paragraph the authors speak about the reusability of lipase CA. They say that lipase is stable for three reaction cycles. However they do not show the results of these experiments. Why?. I think that some figure or table where this stability can be observed should be shown.
Page 11, lines 325-327. I am not an expert English speaker but I think that the sentence “C. echinulata-GEs and EPA-GEs significantly affected…..” is not well written.
Author Response
Dear reviewer, thank you very much for your work on our manuscript. Below is our reply to your comments.
Page 2, line 88. Reference [36] is really the reference [35]. It would be convenient revise all the reference numbers.
Re: The reference numbers were corrected.
Page 2, lines 92-94. The last sentence “We concluded that GEs…” seems a conclusion and this is the introduction section. Therefore it is not the more suitable place for this sentence.
Re: We agree that this is a conclusion. But it is a common style adopted by many journals, so that the main conclusion is available to readers early. However, if you insist, we could remove this sentence in a second round of review.
Page 3, line 141 and along the article. I do not understand why the authors always write “% conversion” or “conversion %”. I think that writing “conversion” is enough. The “%” is the unit and it is not necessary to write the unit each that the word “conversion” appears.
Re: According to the reviewer's suggestion, the respective sentences were rephrased and in many cases the unit % was removed.
Page 4, line 157. I think that washing the lipase with ethanol is not a good idea because it is known that short chain alcohols (methanol and ethanol) can deactivate the lipases.
Re: We agree with reviewer that short chain alcohols can deactivate lipases. However, the use of ethanol here is necessary to remove any traces of FAMEs that may be present. We explain this in the revised version of the manuscript (page 4: “Short chain alcohols may deactivate lipase, but the use of ethanol here is necessary to remove any traces of FAMEs that may be present”).
Page 6, lines 224-227. In this paragraph the authors speak about the reusability of lipase CA. They say that lipase is stable for three reaction cycles. However they do not show the results of these experiments. Why?. I think that some figure or table where this stability can be observed should be shown.
Re: According to the reviewer’s suggestion we provide the following data in the revised version: “It was found that the conversion rate using the regenerated enzyme remained essentially the same for three reaction cycles, while in the fourth cycle the conversion rate was reduced to 88% of the original, which is important for the viability of the process”. We think that providing data in the form of a Table or Figure will not be of interest to readers.
Page 11, lines 325-327. I am not an expert English speaker but I think that the sentence “C. echinulata-GEs and EPA-GEs significantly affected…..” is not well written.
Re: According to the reviewer suggestion we reworded the sentence as follows: “C. echinulata-GEs and EPA-GEs were more effective against all tested bacteria compared to N. gaditana-GEs and olive oil-GEs”.
Reviewer 2 Report
The manuscript deals with an enzymatic synthesis of glucose fatty acid esters. The authors have presented well-reported research, the touch very good points and research should be focussed on such type of esters.
The topic is in line with the scope of this journal and relevant for the synthesis such type of esters.
Please avoid lump sum references such as [1-4] in line 49, [24-26] in line 72 or [29-32] in line 77. Each reference should be described in detail, discriminating the main outcomes among all.
In line 99 in the formula MgSO4, 4 should be subscript
In line 177 should be define SPSS 9.0
During the interpretation of the FTIR spectra should make the analysis of the origin signal at 3380 cm-1 derived from (OH). Whether they come from sugar or other compounds, for example acid.
Overall, the manuscript has been well presented showing interesting results. Please emphasise the conclusion section summarizing the main outcomes to improve the archival. In general, the plots' readability and quality should be improved.
I would like to recommend it for publication after a revision, please consider to highlights the novelty of this manuscript.
Author Response
Dear reviewer, thank you very much for your work on our manuscript. Below is our response to your comments.
Please avoid lump sum references such as [1-4] in line 49, [24-26] in line 72 or [29-32] in line 77. Each reference should be described in detail, discriminating the main outcomes among all.
Re: According to the reviewer’s suggestion the references were separated and moved to the right place in the sentences.
In line 99 in the formula MgSO4, 4 should be subscript
Re: Done
In line 177 should be define SPSS 9.0
Re: Done
During the interpretation of the FTIR spectra should make the analysis of the origin signal at 3380 cm-1 derived from (OH). Whether they come from sugar or other compounds, for example acid.
Re: Dear reviewer, this is already explained in section 3.3.
Overall, the manuscript has been well presented showing interesting results. Please emphasise the conclusion section summarizing the main outcomes to improve the archival. In general, the plots' readability and quality should be improved. I would like to recommend it for publication after a revision, please consider to highlights the novelty of this manuscript.
Re: We tried to improve Conclusion and various parts of the manuscript. Please consider the marked version of the manuscript.
