Production of the Cellulase Enzyme System by Locally Isolated Trichoderma and Aspergillus Species Cultivated on Banana Pseudostem during Solid-State Fermentation
Round 1
Reviewer 1 Report
The purpose of the study was to use the banana pseudostem as an inducing substrate for cellulase production by locally isolated Trichoderma and Aspergillus species in the solid state fermentation (SSF) process. It was mentioned by the authors that cellulases are mostly obtained through submerged fermentations (SmF) using genetically modified strains of Trichoderma. However, the production costs of these enzymes in SmF are very high. The work is an important from economic and ecological point of view. The authors underline that the use of agricultural biomass such as banana waste as feedstock may reduce the use of food crops such as corn and wheat used as carbon source for biotechnological processes. It also can minimize the generation of pollutants and harmful wastes. The manuscript is an interesting piece of work. The experiments were well designed, the content of the state of art provides useful information about the topic. As was mentioned by the authors the results of the study showed that banana pseudostem had the potential as a cheap and abundant substrate for the production of cellulases. However the manuscript has to be revised. My recommendation is to accept the article for the possible publication in “Fermentation” after the revision.
Authors need to revise the methodology references sections.
Lines 106
The authors mentioned microbiological medium Malt extract, but they did not include companies (which should be in brackets) e.g.: Malt extract (MEA) (company, city country);
Lines 106
The authors mentioned chemicals such as: Tween 80 (Merck), but they did not include companies (which should be in brackets) e.g.: Tween 80 (Merck, city country);
Line 116
Beckman Coulter Allegra X 22R refrigerated benchtop centrifuge (company, city, country) is required;
Lines 127, 128, 138
Scientific, Digital Model 127 no. 276 (company, city country),
crushing machine (Zhuans, Electric model, company, city country);
(HL-340 Vertical Type Steam Steri- 138 lizer, company, city, Taiwan)
Line 159
(Incubator Shaker Series, New Brunswick, EXCELLA E25R, city, country);
Line 167, 195
Beckman Coulter Allegra X 22R refrigerated benchtop centrifuge (city country),
Beckman Coulter, DU® 195 720 UV/Vis spectrophotometer (city country)
Additionally, References section should be revised throughout according to instructions for authors of the Fermentation journal (Journal Names should be listed as Abbreviated Journal Names).
Author Response
Dear Reviewer
Thank you for the critical reviewing and the constructive feedback on the manuscript titled “ Production of the cellulase enzyme system by locally isolated Trichoderma and Aspergillus species cultivated on banana pseudostem during solid-state fermentation - 2312307” sent to the Journal Processes. The concerns/comments/suggestions were addressed as outlined below.
Authors need to revise the methodology references sections.
Lines 106
The authors mentioned microbiological medium Malt extract, but they did not include companies (which should be in brackets) e.g.: Malt extract (MEA) (company, city country);
Response – information is added
Lines 106
The authors mentioned chemicals such as: Tween 80 (Merck), but they did not include companies (which should be in brackets) e.g.: Tween 80 (Merck, city country);
Response – information is added
Line 116
Beckman Coulter Allegra X 22R refrigerated benchtop centrifuge (company, city, country) is required;
Response – information is added
Lines 127, 128, 138
Scientific, Digital Model 127 no. 276 (company, city country),
crushing machine (Zhuans, Electric model, company, city country);
(HL-340 Vertical Type Steam Steri- 138 lizer, company, city, Taiwan)
Response – information is added
Line 159
(Incubator Shaker Series, New Brunswick, EXCELLA E25R, city, country);
Response – information is added
Line 167, 195
Beckman Coulter Allegra X 22R refrigerated benchtop centrifuge (city country),
Beckman Coulter, DU® 195 720 UV/Vis spectrophotometer (city country)
Response - information
Additionally, References section should be revised throughout according to instructions for authors of the Fermentation journal (Journal Names should be listed as Abbreviated Journal Names).
Response – references are corrected according to the Journal style.
Reviewer 2 Report
1) The introduction is deficient in reviewing the current state of the research field. Reference 31 should be included in order to make clear that intention in the manuscript was to increase the volumetric activity of the purified enzymes as compared to the fungal strains. The activity enhancement should then be included in the discussion of Table 1 with some standardization of how activity is expressed in order to assist comparisons.
Other relevant studies should be included and briefly discussed, such as, C Krishna, Production of bacterial cellulases by solid state bioprocessing of banana wastes, Bioresource Technology 69 (1999) 231-239. The results in Table 1 should be compared with these references along with activity specifications for commercial cellulases.
The $.30 cost on line 37 seems out of date.
2) Only a limited number of references in the discussion section actually deal with banana waste fermentation, 77 and 81-84. This number should be increased to include temperature and moisture content parameters and more details given for all with respect to comparisons with the current study.
3) There is no follow-up to the statement on line 575 about the dominance of Trichoderma in co-cultivation relative to A. fumigatus. This could possibly be evaluated in the literature from the point of view of the Trichoderma species known biostimulant and pesticide properties towards banana plants.
Experimentally, the co-cultivation of T. longibrachiatum and T. harzianum would be interesting.
4) The improved designation on line 614 is somewhat misleading since it was T. longibrachiatum acting alone which gave the highest cellulase activity according to Fig 5. What is confirmed on line 614 is that co-cultivation gave more activity than the two strains acting individually.
Author Response
Dear Reviewer
Thank you for the critical reviewing and the constructive feedback on the manuscript titled “ Production of the cellulase enzyme system by locally isolated Trichoderma and Aspergillus species cultivated on banana pseudostem during solid-state fermentation - 2312307” sent to the Journal Processes. The concerns/comments/suggestions were addressed as outlined below.
1) The introduction is deficient in reviewing the current state of the research field. Reference 31 should be included in order to make clear that intention in the manuscript was to increase the volumetric activity of the purified enzymes as compared to the fungal strains. The activity enhancement should then be included in the discussion of Table 1 with some standardization of how activity is expressed in order to assist comparisons.
Other relevant studies should be included and briefly discussed, such as, C Krishna, Production of bacterial cellulases by solid state bioprocessing of banana wastes, Bioresource Technology 69 (1999) 231-239. The results in Table 1 should be compared with these references along with activity specifications for commercial cellulases.
The $.30 cost on line 37 seems out of date.
Response – Additional information is provided in the respective section according to the comments. -
2) Only a limited number of references in the discussion section actually deal with banana waste fermentation, 77 and 81-84. This number should be increased to include temperature and moisture content parameters and more details given for all with respect to comparisons with the current study.
Response – additional information pertaining banana wastes is provided
3) There is no follow-up to the statement on line 575 about the dominance of Trichoderma in co-cultivation relative to A. fumigatus. This could possibly be evaluated in the literature from the point of view of the Trichoderma species known biostimulant and pesticide properties towards banana plants.
Experimentally, the co-cultivation of T. longibrachiatum and T. harzianum would be interesting.
Response – clarity is provided.
4) The improved designation on line 614 is somewhat misleading since it was T. longibrachiatum acting alone which gave the highest cellulase activity according to Fig 5. What is confirmed on line 614 is that co-cultivation gave more activity than the two strains acting individually.
Response – the statement is been clarified.
Reviewer 3 Report
This manuscript needs major revision as follows;
1. It is recommended to include the rationale of research in the last section of introduction.
2. Fig cation 1 must be incoporated with Fig 1.
3. Improve the discussion part.
4. to include the statistically significant level in each graph.
Author Response
Dear Reviewer
Thank you for the critical reviewing and the constructive feedback on the manuscript titled “ Production of the cellulase enzyme system by locally isolated Trichoderma and Aspergillus species cultivated on banana pseudostem during solid-state fermentation - 2312307” sent to the Journal Processes. The concerns/comments/suggestions were addressed as outlined below.
This manuscript needs major revision as follows;
- It is recommended to include the rationale of research in the last section of introduction.
Response – additional information is provided
- Fig caption 1 must be incorporated with Fig 1.
Response – this has been rectified.
- Improve the discussion part.
Response – additional information is provided
- To include the statistically significant level in each graph.
Response – information is provided.
Round 2
Reviewer 2 Report
The first paragraph of the discussion would be more readable if broken into several shorter ones, such as at lines 403, 416 and 434. The first paragraph in 4.4 could be broken at line 625.
Reviewer 3 Report
The revised manuscript can be considered for further journal process.
