Progress in Enzymatic Biodiesel Production and Commercialization

Round 1

Reviewer 1 Report

The paper requires major revision such as the following;

1. Generally, the grammar in the paper can be improved greatly. Please pay close attention to the use of past, present and future tenses
2. It is suggested that the authors include some explanatory diagrams to enhance the readability of the paper
3. The connectivity between sections is unclear. Please make sure each section is well introduced in the section before a given section. For example, there is no clear introduction to section 2.1 and etc
4. The paper lacks some fundamental information behind lipase production. It is suggested that such content be added to the paper. The current paper dives quite deep without any prior basic information
5. Please provide a more analytical comparison in Section 5. Authors may consider adding tables and diagrams to help with the analysis of the different enzymatic processes.

Author Response

Dear Editor,

The paper has been revised and the specific revisions are listed as follows:

 

1. Generally, the grammar in the paper can be improved greatly. Please pay close attention to the use of past, present and future tenses

 

Response: corrected.

 

2. It is suggested that the authors include some explanatory diagrams to enhance the readability of the paper

Response: This paper is sort of mini-review to review the most recent progress especially related to industrialization of enzymatic process.

 

3. The connectivity between sections is unclear. Please make sure each section is well introduced in the section before a given section. For example, there is no clear introduction to section 2.1 and etc

Response: rearranged.

4. The paper lacks some fundamental information behind lipase production. It is suggested that such content be added to the paper. The current paper dives quite deep without any prior basic information

Response: Yes, just some simple information related lipase production and focus is put on process improvement in this paper since there is no much significant improvement achieved in the field of reducing the cost of lipase production.

 

5. Please provide a more analytical comparison in Section 5. Authors may consider adding tables and diagrams to help with the analysis of the different enzymatic processes.

 

Response: just a sort of summary and hard to analyze in details.

Reviewer 2 Report

The authors investigate the technological and economic advances achieved in enzymatic biodiesel production process. In my opinion, the review work is well-written and properly structured but some style implementations are needed to better highlight the innovations and progress achieved in the enzymatic biodiesel sector. In this direction, I would propose to include, for some sections, summary tables that compare the yield and economic impact of the various methods and processes discussed in the review. For example:

• In section 2.1, i suggest a summary table or graph on the yield performance of the various microorganism used in free lipase-catalyzed process

 

• In section 2.2, i suggest a summary table or graph on the yield performance and costs of the various technologies used in immobilization process

 

• In section 5, a summary table on pro&cons about the enzymatic process could be useful for readers

Other comments on the paper are reported below:

• Introduction:.....which mainly includes reducing enzyme cost, expanding low quality raw materials and improving enzymatic process and reactors. Please, provide references about this statement.

 

• Introduction: I suggest implementing the introduction with by mentioning the application fields of biodiesel technology

 

• Section 2.1: Please, specify the meaning of LipC

 

• Section 2.1:  Cesarini et al.....Please, provide reference.

 

• Section 4: Provide a brief description of the novel reactors discussed in the section.

 

• Section 6: This section would seem more a conclusion/summary of the manuscript rather than an analysis of the future prospects of the enzymatic biodiesel production technology. Please, revise it.

Author Response

• Dear Editor,

  The paper has been revised and the specific revisions are listed as follows:

  In section 2.1, i suggest a summary table or graph on the yield performance of the various microorganism used in free lipase-catalyzed process
• Response: this focus of this part is not comparing the performance of lipases produced by different microorganisms and there is no enough information available for the comparison.
• In section 2.2, i suggest a summary table or graph on the yield performance and costs of the various technologies used in immobilization process
• Response: the performance comparison has been given in many other reviews and this review focus on the most recent progress of enzymatic process improvement. The cost information is available.
• In section 5, a summary table on pro&cons about the enzymatic process could be useful for readers
• just a sort of summary and hard to analyze in details.

Other comments on the paper are reported below:

• Introduction:.....which mainly includes reducing enzyme cost, expanding low quality raw materials and improving enzymatic process and reactors. Please, provide references about this statement.
• Response: added.
• Introduction:I suggest implementing the introduction with by mentioning the application fields of biodiesel technology
• Response: More information has been added in the introduction part.
• Section 2.1:Please, specify the meaning of LipC
• Response: Corrected.
• Section 2.1:Cesarini et al.....Please, provide reference.
• Response:Provided.
• Section 4:Provide a brief description of the novel reactors discussed in the section.
• Response: Provided.
• Section 6: This section would seem more a conclusion/summary of the manuscript rather than an analysis of the future prospects of the enzymatic biodiesel production technology. Please, revise it.
• Response: Yes & Revised.

Reviewer 3 Report

Authors provided a review article referring to enzymatic biodiesel synthesis, as well as its development and commercialization. The manuscript consists of 6 sections, but most of them are relatively short and sections are not comprehensively described and in my opinion, should be definitely improved. Review article provided some interesting information and fits Processes journal scope, but should be reconsidered after major revision.

 

Below I present comments and suggestions:

1. The aim of the work should be specified and rephrased in the abstract and introduction.
2. The manuscript has not any figures and tables, which in my opinion is unacceptable. Review articles are written to review the knowledge on a selected research issue. Collecting the data in tables makes it easier for readers to analyze them later. I propose to add, e.g. scheme of the biodiesel synthesis.
3. I suggest also to prepare some tables to improve the manuscript, e.g. table referring processes for enzyme protection or utilization of raw materials or wastes for biodiesel synthesis.
4. Section 4. should be expanded.
5. Section 6. should be rephrased. The last section should summarize the information found in the manuscript. At the moment, these paragraphs are short and too concise.
6. More new articles should be added to the manuscript. Less than 15% of the articles cited are from 2018-2020. After a while of searching, you can easily find many articles on enzymatic biodiesel synthesis:
7. https://doi.org/10.3390/pr8091118
8. https://doi.org/10.3390/en13102588
9. https://doi.org/10.1515/ijfe-2019-0089
10. https://doi.org/10.1002/btpr.3109
11. https://doi.org/10.1007/s10562-020-03367-w
12. https://doi.org/10.3390/catal10070738
13. https://doi.org/10.1016/j.renene.2020.02.100

 

Minor suggestions:

1. In 2.1. Subsection it should be: "Cesarini et al. [reference number] conducted..."
2. The same on the 5th page ("Li et al used free lipase").
3. In the paragraph: "Some plant oils, like crude palm oil and PFAD" the references are missed. Besides this subsection is quite short and should be improved. Surely You can find more scientific literature on this issue.
4. Please, correct the reference list according to Instruction for authors.

Author Response

Dear Editor,

The paper has been revised and the specific revisions are listed as follows:

 

1. The aim of the work should be specified and rephrased in the abstract and introduction.

Response: Improved.

2. The manuscript has not any figures and tables, which in my opinion is unacceptable. Review articles are written to review the knowledge on a selected research issue. Collecting the data in tables makes it easier for readers to analyze them later. I propose to add, e.g. scheme of the biodiesel synthesis.

Response: this paper is sort of mini-review to review the most recent progress especially related to industrialization of enzymatic process. There are tremendous review about lipase-mediated biodiesel production published and this review specially focus on some significant improvement on enzymatic process especially for industrial application.

 

 

3. I suggest also to prepare some tables to improve the manuscript, e.g. table referring processes for enzyme protection or utilization of raw materials or wastes for biodiesel synthesis.

Response: this paper is sort of mini-review to review the most recent progress especially related to industrialization of enzymatic process. There are tremendous review about lipase-mediated biodiesel production published and this review specially focus on some significant improvement on enzymatic process especially for industrial application.

 

4. Section 4. should be expanded.

Response:This mini-review specially focus on some significant improvement on enzymatic process especially for industrial application.

 

5. Section 6. should be rephrased. The last section should summarize the information found in the manuscript. At the moment, these paragraphs are short and too concise.

Response: revised.

6. More new articles should be added to the manuscript. Less than 15% of the articles cited are from 2018-2020. After a while of searching, you can easily find many articles on enzymatic biodiesel synthesis:

Response：some most related reference added.

Minor suggestions:

1. In 2.1. Subsection it should be: "Cesarini et al. [reference number] conducted..."
2. The same on the 5th page ("Li et al used free lipase").
3. In the paragraph: "Some plant oils, like crude palm oil and PFAD" the references are missed. Besides this subsection is quite short and should be improved. Surely You can find more scientific literature on this issue.
4. Please, correct the reference list according to Instruction for authors.

Response: Corrected.

 

Round 2

Reviewer 1 Report

Authors have addressed all comments

Author Response

Response: Thanks for your comments on the paper.

Reviewer 2 Report

Although the changes to Section 6, Section 4 and references have been correctly performed, the request to insert summary tables or graphics was not accepted by the authors. This greatly limits the clarity of the manuscript.

However, in order to provide a mini-review, I consider the article to be published.

Author Response

Response: Yes, it is a mini-review and thanks for your understanding.

Reviewer 3 Report

As the authors themselves have noted the tremendous amount of review articles about lipase-mediated biodiesel production were published in recent years, hence I think that authors' mini-review should summarize recent insights and advances in biodiesel research and authors should focus more on the recently published articles. The aim of the mini-reviews is to evaluate the progress, as well as show the future perspectives.

The manuscript has been improved only in part. In my opinion, most of the suggestions of reviewers should be taken into account.

I found that the authors did not add any new references, besides no 73, which was not included in the reference list earlier.

A part of the red colour improvements it is just a rephrased text of the previous version of the manuscript.

In my opinion, the tables, schemes or figures should definitely appear in the final version of the manuscript.

Minor suggestions:
- On the 5th page it should be: "Li et al. [reference number] used free lipase...".
- The last reference in the reference list should be corrected.

 

Author Response

Response: 

1. To avoild the similarity issue, we rephrased some part sentences as requried in the revised version. And we think it is necessary.
2. Yes. We added reference 73 based on the related information. the reference is cited is depended on the contents necessary cited in the paper.
3. The format of the last reference is corrected.
4. The place of refence 56 is corrected.
5. Fig.1 indicating "Biodiesel production contribution by different countries for the year 2018" is inculded in the review.

Round 3

Reviewer 3 Report

The manuscript should be accepted.

Author Response

Thanks.