Simultaneous Bioconversion of Gelatinized Starchy Waste from the Rice Noodle Manufacturing Process to Lactic Acid and Maltose-Forming α-Amylase by Lactobacillus plantarum S21, Using a Low-Cost Medium

Round  1

Reviewer 1 Report

- Please clearly state why your work differs from your previous articles: a) Kanpiengjai, A.; Lumyong, S.; Pathom-aree, W.; Khanongnuch, C. Starchy effluent from rice noodle manufacturing process as feasible substrate for direct lactic acid production by Lactobacillus plantarum S21. J. Korean Soc. Appl. Biol. Chem. 2014, 57, 217-220, doi:http://dx.doi.org/10.1007/s13765-013-4311-2 and b) Kanpiengjai, A.; Rieantrakoonchai, W.; Pratanaphon, R.; Pathom-aree, W.; Lumyong, S.; Khanongnuch, C. High efficacy bioconversion of starch to lactic acid using an amylolytic lactic acid bacterium isolated from Thai indigenous fermented rice noodles. Food Sci. Biotechnol. 2014, 23, 1541-1550, doi:http://dx.doi.org/10.1007/s10068-014-0210-5. Please underline these novel aspects in the title and in the abstract, clearly differentiating it from your previous studies, providing good reason to cite this article in addition to your past works.

- please report the strain name also for V. cholera throughout the manuscript

- please cite throughouth the manuscript references testifying the interest of Fermentations and MDPI Publisher in the subjects you deal with…e.g.

https://www.mdpi.com/2311-5637/5/1/26

https://www.mdpi.com/2311-5637/5/1/20

https://www.mdpi.com/2311-5637/5/1/12

- In the introduction, please introduce in few lines the potential of L. plantarum in food biotechnology…e.g.

https://www.mdpi.com/2304-8158/6/12/110

https://www.mdpi.com/2072-6643/11/2/353

https://www.mdpi.com/2311-5637/3/4/65

- Line 19: please italicized bacterial name

- Line 30: please italicized bacterial names

- Line 56: Yousuf, - please eliminate the comma

- Line 57: pretreatment

- Line 70: generally recognized as safe (GRAS)

- Caption figure 4: please italicized bacterial names

- Line 271: you mention ‘activity against E. coli 25922’…why you do not report this finding also in the abstract/discussion

- Lines 289-292: please change as follows “The result of nitrogen source screening clearly confirmed the importance of the nutritional requirements for the growth of LAB [12,22] as the highest yield of lactic acid was achieved from the original MRS medium tailored for LAB development”

- Line 310 : was able to lead to an increased convertion

- Please discuss the relevance of your findings also in the field of pasta cooking. You propose a possible further piece in the puzzle of LAB application in pasta-making https://www.frontiersin.org/articles/10.3389/fmicb.2012.00094/full

Author Response

Response to reviewer 1 comments

Point 1.           Please clearly state why your work differs from your previous articles: a) Kanpiengjai, A.; Lumyong, S.; Pathom-aree, W.; Khanongnuch, C. Starchy effluent from rice noodle manufacturing process as feasible substrate for direct lactic acid production by Lactobacillus plantarum S21. J. Korean Soc. Appl. Biol. Chem. 2014, 57, 217-220, doi:http://dx.doi.org/10.1007/s13765-013-4311-2 and b) Kanpiengjai, A.; Rieantrakoonchai, W.; Pratanaphon, R.; Pathom-aree, W.; Lumyong, S.; Khanongnuch, C. High efficacy bioconversion of starch to lactic acid using an amylolytic lactic acid bacterium isolated from Thai indigenous fermented rice noodles. Food Sci. Biotechnol. 2014, 23, 1541-1550, doi:http://dx.doi.org/10.1007/s10068-014-0210-5.

Respond 1:     Reference (a) is the report described the production of lactic acid by L. plantarum S21 using the starchy effluent (non-gelatinized starchy waste) from noodle factory and the experiments on lactic acid production are based on the MRS medium. While the reference (b) described the production of lactic acid by the same LAB strain, but using cassava starch as a substrate and based on MRS medium.

Differ from both (a) and (b), the recent paper described the efforts to change the medium composition and we have succeeded in optimization and achieved the low cost medium containing only gelatinized starchy waste (GSW) from noodle factory and corn steep liquor (CSL).

Point 2            Please underline these novel aspects in the title and in the abstract, clearly   differentiating it from your previous studies, providing good reason to cite this article in addition to your past works.

Respond 2:     The difference between the results in this manuscript to the previous work is the “type of starchy waste”. So, we inserted the word “gelatinized” in the title. Additional to the difference in substrate, we want to emphasize the successful achieving “a low cost medium” that contains only GSW and CSL and it is already appeared in the title (green highlighted). The other novelties of this work are also presented in the green highlighted

Point 3.-          please report the strain name also for V. cholera throughout the manuscript

Respond 3:     The strain name of V. cholerae is “TH-001” which is a clinical strain obtained from School of Allied Health Science, University of Phayao (clearly stated in the section materials and method). The strain name is corrected throughout the manuscript as suggested.

Point 4            please cite throughouth the manuscript references testifying the interest of Fermentations and MDPI Publisher in the subjects you deal with…e.g.

https://www.mdpi.com/2311-5637/5/1/26   

https://www.mdpi.com/2311-5637/5/1/20

https://www.mdpi.com/2311-5637/5/1/12

- In the introduction, please introduce in few lines the potential of L. plantarum in food biotechnology…e.g.

https://www.mdpi.com/2304-8158/6/12/110

https://www.mdpi.com/2072-6643/11/2/353

https://www.mdpi.com/2311-5637/3/4/65

Respond 4:     All suggested six references were cited in the manuscript as suggested and also added to reference list (No. 10, 11, 20, 21, 22 and 33). The changed points are the blue highlighted

Point 5-           Line 19: please italicized bacterial name

Respond 5 : Bacterial name is italicized as suggested (line 20).

Point 6-           Line 30: please italicized bacterial names

Respond 6 :    Bacterial name is italicized as suggested (line 31).

Point 7            Line 56: Yousuf, - please eliminate the comma

Respond 7 :    Comma is eliminated as suggested (line 58).

Point 8            Line 57: pretreatment

Respond 8 :    The word is corrected as suggested (line 59).

Point 9            Line 70: generally recognized as safe (GRAS)

Respond 9 :    The word is corrected as suggested (line 75).

Point 10          Caption figure 4: please italicized bacterial names

Respond 10 : The word is corrected as suggested.

Point 11          Line 271: you mention ‘activity against E. coli 25922’…why you do not report this finding also in the abstract/discussion.

Respond 11 :  Due to word number in the abstract is limited to not more than 200 words, then we deleted the name of E. coli ATCC 25922 from the abstract. However, we have already added this information in the abstract in revision R1.

Point 12-          Lines 289-292: please change as follows “The result of nitrogen source screening clearly confirmed the Importance of the nutritional requirements for the growth of LAB [12,22] as the highest yield of lactic acid was achieved from the original MRS medium tailored for LAB development”

Respond 12:   The sentence is changed as suggested (line 297-299).

Point 13          Line 310 : was able to lead to an increased conversion

Respond 13:   The sentence is changed as suggested (line 322).

Point 14-         Please discuss the relevance of your findings also in the field of pasta cooking. You propose a possible further piece in the puzzle of LAB application in pasta-making https://www.frontiersin.org/articles/10.3389/fmic

Respond 14:    The discussion on the relevance of this paper to our finding is added in the part of introduction and discussion as suggested (No.23) (line 366-372).

Reviewer 2 Report

I consider that the study performed and presented in the manuscript “ Simultaneous bioconversion of starchy waste from 2 rice noodle manufacturing process to lactic acid and 3 maltose-forming -amylase by Lactobacillus 4 plantarum S21 using a low-cost medium” is of interest for audience looking at the production of lactic acid and enzymes from low cost substrates.  Thus, I believe that this article is suitable for the journal of Fermentation MDPI. However, I suggest that some minor corrections are required in the manuscript before full acceptance. 1.- pg.3 L110: Can you please confirm if the MRS medium was formulated with all nutrients of MRS and only the conventional nitrogen source (yeast extract, beef extract and peptone) was replaced by the low cost nitrogen sources. 2.- Table 2 and Table 3 please add as a table foot note or in the table headings the conditions at which the fermentation was performed. 3.- pg7, L224: Can you please explain what is your justification for the selected CSL values in section 3.3. As in previous assays your values were of 1 to 10 g/L and in the CCD test your CSL values were 86.6 g/L to 300 g/L. 4.- pg7, L246: correct "in in"

Author Response

Response to reviewer 2 comments

Comments and Suggestions for Authors

I consider that the study performed and presented in the manuscript “Simultaneous bioconversion of starchy waste from rice noodle manufacturing process to lactic acid and maltose-forming a-amylase by Lactobacillus plantarum S21 using a low-cost medium” is of interest for audience looking at the lactic acid production and enzymes from low cost substrates. Thus, I believe that this article is suitable for the journal of Fermentation MDPI. However, I suggest that some minor corrections are required in the manuscript before full acceptance.

Point 1.            pg.3 L110: Can you please confirm if the MRS medium was formulated with all nutrients of MRS and only the conventional nitrogen source (yeast extract, beef extract and peptone) was replaced by the low cost nitrogen sources.

Respond 1      Thank you for this suggestion. In this experiment, the modified MRS medium was used and have already revised sentence and cite the reference paper (line 115-116, yellow highlighted). Yes, we confirm our experiment is conducted by removal of yeast extract, beef extract and peptone and replaced by the tested low cost nitrogen sources.

Point 2.           Table 2 and Table 3 please add as a table foot note or in the table headings the conditions at which the fermentation was performed.

Respond 2      The culture condition was added on the table headings as suggested (yellow highlighted).

Point 3.            pg7, L224: Can you please explain what is your justification for the selected CSL values in section 3.3. As in previous assays your values were of 1 to 10 g/L and in the CCD test your CSL values were 86.6 g/L to 300 g/L.

Respond 3      To our justification, the proper concentration that should be used in CCD     experiment is designed based on the values of Coefficient and p-value (in Table 2) which is obtained from the analysis of data from Plackett and Burman design”. The plus symbol (+) of coefficient indicated the positive effect of CSL is the nutritional factor influence on the target product (lactic acid). That means in CCD experiment, the quantity of CSL must be increase corresponding to the degree of the coefficient.

Table 2. The Plackett-Burman design for screening significant variables in lactic acid production under static condition at 37 ^oC for 24 h.

Point 4.            pg7, L246: correct "in in" 

Respond 4      We have corrected as suggested (line 259).

Reviewer 3 Report

Well-designed and described experimental section. The originality of the concept was not high from a short research in the literature, but the way experiments are exhibited is interesting. I would like to see extra comments for the limitations that may occur if the bioconversion takes place in industrial scale. 

Author Response

Response to reviewer 3 comments

Well-designed and described experimental section. The originality of the concept was not high from a short research in the literature, but the way experiments are exhibited is interesting. I would like to see extra comments for the limitations that may occur if the bioconversion takes place in industrial scale. 

Respond to reviewer 3

We have succeeded in optimization for lactic acid production in laboratory scale. However, the up-scaling in the pilot scale is our target prior the production in the large or industrial scale. We would like to explain for some li

The limitation may rise from some natural properties of substrate. The gelatinized starchy waste is the cooked starch remaining the noodle processing. The viscosity of this substrate can cause the problem of mixing, but it will be better after the rapid growth of L. plantarum S21 which is originally isolated from fermented starch.

In additional to the problem caused from the substrate viscosity, the properties of CSL available from factory might be also the problem due to the different in composition particularly protein content and metal ion. Lower in protein content may effect on either the lactic acid yield or conversion efficiency. Some undesirable metal ion may inhibit the growth of microbe. However, the standardization of CSL before using is necessary requirement.

Round  2

Reviewer 1 Report

Dear Authors, 

thank you for your revisions. Regards,

Author Response

Response to Reviewer 1 (round 2)

Respond:

We appreciated your kind suggestion. We have carefully checked again for English spelling and have also corrected totally 11 points as showed by the pink highlighted in R2 version. We hope that the R2 version will be possible to publish in the Fermentation.

In addition, we would like to inform that before submitting to the Fermentation, our manuscript has been sent to edit for English by Elsevier English editing. (The certificated and invoice are attached). We also would like to confirm that if the Fermentation (MDPI) judged that our manuscript still required more English Editing, we will follow the suggestion. However, due to the time limited, it will take at least 2-3 days, that would be late for the manuscript acceptance we need. It would be grateful if we will be able to get the acceptance first, then we will process the English editing later.