Biotechnological Potential of Lignocellulosic Biomass as Substrates for Fungal Xylanases and Its Bioconversion into Useful Products: A Review
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript demonstrates biotechnology potential of lignocellulosic biomass for fungal xylanase production, their purification, molecular substrates to improve their efficiency, and their applications in the production of valuable products and other industrial processes. This study focuses on the use of microbial enzymes to transform agricultural residues into different value-added products, which makes the biological process more sustainable economically. Therefore, I recommend its publication after major revision. Some additional comments are listed as follows:
1. In the third part, xylanase should be described in more detail, and the mechanism that xylanase combines with different enzymes to hydrolyze polysaccharides in destroying plant cell walls should be introduced in detail.
2. In the fourth part of xylanase production, authors emphasize two production methods are SMF and SSF, and different conditions affected xylanase production are introduced in detail. However, the comparison between SMF and SSF is not mentioned, which should be added to highlight the advantages of SSF.
3. Why is the seventh part after the fifth part? 7.3 is followed by 7.5, and part 7.4 is missing. The format should be checked.
4. In the seventh part, the application of fungal xylanase in the biotransformation of lignocellulose into useful products, there are references to the biotransformation of lignocellulose biomass into biofuels and prebiotics, the biological bleaching of paper and kraft pulp, and the nutritional enhancement in plant-based diet. Therefore, the food modification mentioned above should be discussed in detail?
5. The conclusion mentions that RDT, synthetic biology and conventional technology are working together to achieve the goal of effective xylanase production with the required industrial characteristics. The comparison of these three methods should be added to respond to this conclusion.
Comments on the Quality of English LanguageModerate editing of English language required
Author Response
Reviewer 1:
This manuscript demonstrates biotechnology potential of lignocellulosic biomass for fungal xylanase production, their purification, molecular substrates to improve their efficiency, and their applications in the production of valuable products and other industrial processes. This study focuses on the use of microbial enzymes to transform agricultural residues into different value-added products, which makes the biological process more sustainable economically. Therefore, I recommend its publication after major revision. Some additional comments are listed as follows:
Q.1. In the third part, xylanase should be described in more detail, and the mechanism that xylanase combines with different enzymes to hydrolyze polysaccharides in destroying plant cell walls should be introduced in detail.
Response: We have added the information in revised manuscript (Line No. 141-194).
Q.2. In the fourth part of xylanase production, authors emphasize two production methods are SMF and SSF, and different conditions affected xylanase production are introduced in detail. However, the comparison between SMF and SSF is not mentioned, which should be added to highlight the advantages of SSF.
Response: We have added the information in line no. 211 to 223.
Q.3. Why is the seventh part after the fifth part? 7.3 is followed by 7.5, and part 7.4 is missing. The format should be checked.
Response: Thank you very much. We have corrected the numbering.
Q.4. In the seventh part, the application of fungal xylanase in the biotransformation of lignocellulose into useful products, there are references to the biotransformation of lignocellulose biomass into biofuels and prebiotics, the biological bleaching of paper and kraft pulp, and the nutritional enhancement in plant-based diet. Therefore, the food modification mentioned above should be discussed in detail?
Response: Thank you very much. We have discussed in detail about the food modification using xylanases (Line no. 637-737).
Q.5. The conclusion mentions that RDT, synthetic biology and conventional technology are working together to achieve the goal of effective xylanase production with the required industrial characteristics. The comparison of these three methods should be added to respond to this conclusion.
Response: Thank you very much. We have added this information at the end of conclusion section (Line no. 769-774).
Q.6. Moderate editing of English language required
Response: Thank you very much. We have improved the language of the article.
Reviewer 2 Report
Comments and Suggestions for AuthorsComments on fermentation-2812935-peer-review-v1:
This article offers a comprehensive analysis of the utilization of lignocellulosic biomass in biotechnological applications, focusing particularly on fungal xylanases. It covers various aspects such as the categorization and action mechanism of xylanases, their production, and the application of fungal xylanases in different industries. It also explores molecular strategies for improving the efficiency of fungal xylanases and discusses their role in the bioconversion of lignocellulosic biomass into valuable products. My overall opinion is that this paper could be a interesting valuable paper if major modifications are implemented.
1.Elaborate on the methodologies used for the production and application of fungal xylanases. Specific technical details can enhance the paper's utility for researchers in the field.
2.Please express incorporate case studies or real-world examples to illustrate the practical applications of fungal xylanases. This can help bridge the gap between theory and practice.
3.Please draw a comparative analysis of different fungal xylanases, highlight their unique properties and efficiencies in various.
4.Please Utilize more charts, graphs, or infographics to represent complex data or processes. Visual aids can make the paper more accessible and engaging.
5.Add a section discussing the environmental impact of using lignocellulosic biomass, addressing sustainability concerns.
6. The references should be expanded. Some new literatures might be help the authors to further deepen the understanding of reaction mechanism as well as newest developing in this field (Journal of Environmental Management, 2023, 326: 116790 Regeneration mechanism of a novel high-performance biochar mercury adsorbent directionally modified by multimetal multilayer loading).
Author Response
Reviewer 2:
This article offers a comprehensive analysis of the utilization of lignocellulosic biomass in biotechnological applications, focusing particularly on fungal xylanases. It covers various aspects such as the categorization and action mechanism of xylanases, their production, and the application of fungal xylanases in different industries. It also explores molecular strategies for improving the efficiency of fungal xylanases and discusses their role in the bioconversion of lignocellulosic biomass into valuable products. My overall opinion is that this paper could be an interesting valuable paper if major modifications are implemented.
Q.1. Elaborate on the methodologies used for the production and application of fungal xylanases. Specific technical details can enhance the paper's utility for researchers in the field.
Response: Thank you very much. We have given this information in manuscript (Line no. 233-332).
Q.2.Please express incorporate case studies or real-world examples to illustrate the practical applications of fungal xylanases. This can help bridge the gap between theory and practice.
Response: Thank you very much. We have already added the available information in manuscript.
Q.3. Please draw a comparative analysis of different fungal xylanases, highlight their unique properties and efficiencies in various.
Response: We have added details on different fungal xylanses (Supplementary Fig. 2 and supplementary Table 3).
Q.4.Please Utilize more charts, graphs, or infographics to represent complex data or processes. Visual aids can make the paper more accessible and engaging.
Response: We have added some more figures in revised manuscript (Fig. 2). More figures are given in supplementary data.
Q.5.Add a section discussing the environmental impact of using lignocellulosic biomass, addressing sustainability concerns.
Response: Thank you very much. We have added this information in revised manuscript (line no. 96-105).
Q.6. The references should be expanded. Some new literatures might be help the authors to further deepen the understanding of reaction mechanism as well as newest developing in this field (Journal of Environmental Management, 2023, 326: 116790 Regeneration mechanism of a novel high-performance biochar mercury adsorbent directionally modified by multimetal multilayer loading).
Response: Thank you very much. We have added this information in revised manuscript (ref. No. 118).
Reviewer 3 Report
Comments and Suggestions for AuthorsThe subject of this review is relevant. Overall, the review on the xylanase production was good, but application part needs to improve. Below are detailed comments:
1. Line 37, Hemicellulose should be in plural. Please make the change throughout the manuscript.
2. Line 55, megaram change to Tonne to be consistent.
3. Table 1, please list what types of xylananse as those shown in Fig. 1b. If combinations of types of xylanase, please also make it clear.
4. Line 223, “improving”
5. Line 426, replace “changed” with “fractionated”
6. Lines 427-430, Dilute acid pretreatment (line 429) is known incapable of delignification (Line 427). Ref. [49] is a review itself, you need to provide original work.
7. Line 430, “cellulase” not “cellulose”
8. Lines 432 – 443, using g/l has no meaning as the concentration large depends on biomass solids loading.
9. Section 7.5, Xylanase cannot remove lignin, it only remove xylanase, so, it cannot be “an alternative to chlorine-containing chemicals” (line 527). Lines 531-532, needs to illustrate the mechanism of xylanase improving bleaching. Please refer to the work of J. Cleaner Production 363, 132351 DOI:10.1016/j.jclepro.2022.132351 on the mechanism of xylanase improving bleaching: improving the bleaching chemical accessibility to substrate lignin by remove xylan form substrate.
10. Overall, the application sections, needs to point out the xylanase type as shown in Fig. 1a. Needs better explain the performance of a specific xylanase application.
Author Response
Reviewer 3:
The subject of this review is relevant. Overall, the review on the xylanase production was good, but application part needs to improve. Below are detailed comments:
Q.1. Line 37, Hemicellulose should be in plural. Please make the change throughout the manuscript.
Response: Thank you very much. We have corrected this information in revised manuscript.
Q.2. Line 55, megaram change to Tonne to be consistent.
Response: Thank you very much. We have corrected in revised manuscript.
Q.3. Table 1, please list what types of xylananse as those shown in Fig. 1b. If combinations of types of xylanase, please also make it clear.
Response: Thank you very much. We have added this information in revised manuscript.
Q.4. Line 223, “improving”
Response: Thank you very much. We have added this information in revised manuscript.
Q.5. Line 426, replace “changed” with “fractionated”
Response: Thank you very much. We have added this information in revised manuscript.
Q.6. Lines 427-430, Dilute acid pretreatment (line 429) is known incapable of delignification (Line 427). Ref. [49] is a review itself, you need to provide original work.
Response: Thank you very much. This is a general process used for bioethanol production i.e. delignification, saccharification and fermentation. So, there is no need for original reference here.
Q.7. Line 430, “cellulase” not “cellulose”
Response: Thank you very much. We have corrected this information in revised manuscript.
Q.8. Lines 432 – 443, using g/l has no meaning as the concentration large depends on biomass solids loading.
Response: This is the original data taken from literature and authors have presented in g/l. Therefore, we have added as such from these papers.
Q.9. Section 7.5, Xylanase cannot remove lignin, it only remove xylanase, so, it cannot be “an alternative to chlorine-containing chemicals” (line 527). Lines 531-532, needs to illustrate the mechanism of xylanase improving bleaching. Please refer to the work of J. Cleaner Production 363, 132351 DOI:10.1016/j.jclepro.2022.132351 on the mechanism of xylanase improving bleaching: improving the bleaching chemical accessibility to substrate lignin by remove xylan form substrate.
Response: Thank you very much. We have corrected this information in revised manuscript (Line no. 607-611).
Q.10. Overall, the application sections, needs to point out the xylanase type as shown in Fig. 1a. Needs better explain the performance of a specific xylanase application.
Response: Fig. 1 a represents different types of xylanolytic enzymes. Endoxylanases are used in production of prebiotic, Exoxylanases and beta-xylosidases are used in the production of biofuels. This information is well known and explained in many review articles. All types of xylanases are useful in food and feed industries. We have added this information in revised manuscript.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsAll questions I raised previously have been solved, so I would like to recommend its publication on Fermentation.
Reviewer 2 Report
Comments and Suggestions for AuthorsI am very satisfied with the updated and revised version of the manuscript. The authors have greatly improved the quality of the data presented and have addressed all my comments and concerns. I therefore recommend the publication of this research study in its present form.
