Amylolytic Capability and Performance of Probiotic Strains in a Controlled Sorghum Fermentation System
Round 1
Reviewer 1 Report
Comments and Suggestions for Authorsfermentation-2996818-peer-review-v1
Generally, the quality of the manuscript is poor. There is a lack of explanation of replicates and statistical methods used in the study.
1. Introduction, the novelty of the work (and how it is filling the current gap) is missing. Has any similar study been published before? What difference does your work make?
2. It is not clear what the specific purpose of this research is.
3. Why do the authors select strains X and Y as controls?
4. Is the amylase activity important for the selection of Lactobacillus strains for the sorghum fermentation? The exact amylase activity value should be calculated.
5. It is confusing that only four strains were selected for the viscosity measurement. What about the other strains? The caption of Figure 1 should be revised.
6. The error bar and statical results in Figs. 2-5 should be added.
Author Response
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Reviewer 2 Report
Comments and Suggestions for Authors
The study focusses on the evaluation of potential probiotic strains to conduct fermentation of sorghum. The most relevant finding is the amylolytic capacity of two strains allowing them to grow on this substrate which would allow further applications. Main concern about the manuscript relies on the concept of probiotic which is misunderstood. Not all LAB are probiotics and even for LAB species traditionally used as probiotics, not all strains can be considered “probiotic” or beneficial unless this capability has been demonstrated. Material and Methods section should be reorganized. Provide more information about the strains and procedures used. Some specific comments and suggestions follow below:
Abstract
Line 19 “Lactobacillus” should be in italics. Check it all through the text.
Introduction
Lines 28-29, the sentence is not true as it is written. The concept of probiotic is misunderstood. Not all LAB are probiotics nor normal inhabitants of healthy gut. Even for LAB species traditionally used as probiotics, not all strains can be considered “probiotic” or beneficial unless this capability has been demonstrated.
Lines 39-41, this statement should be focused in LAB metabolism which is the objective of the study.
Lines 53-58, it is well documented that organic acids derived from the LAB metabolism have antimicrobial properties. This paragraph should be rewritten in this general sense.
Lines 66-68, the sentence “were shown to possess probiotic properties, even though the assessments were undertaken on different microbiological media and not in the sorghum slurries. Therefore, it is possible to develop probiotic-based sorghum products” should be reworded. It is not clear how the probiotic properties were determined.
Line 69, Lactobacillus plantarum should be Lactiplantibacillus plantarum.
Line 70, “commonly used probiotic strain” this is not correct since no strain is mentioned. It could be said “members of the species L. plantarum”
Material and Methods
Line 81, “2.1 Sample collection” this title makes no sense. Instead, 2.1 and 2.2 should be in the same paragraph as “Bacterial strains and culture conditions”. The list of strains and their source/origin should be provided.
Line 91, it is not clear what kind of control are the strains isolated from pharmaceutical probiotic supplements and who provided these strains to the researchers for the study.
Line 103, 25 ml was the inoculum size or the final volume??
Lines 105, “2.3. Screening and amylolytic activity of potential probiotic strains” Please clarify if strains used in this study are “probiotic or potential probiotics” for coherence with the rest of the text. In addition, “screening” makes no sense as a heading.
I would suggest reorganizing the Mat & Met with a section named i.e. “Sorghum fermentation with LAB strains”, including subsections 2.4-2.7 which correspond to the fermentation experiments and subsection 2.3 renamed as “Amylolytic activity of LAB strains” which in fact contains fermentation experiments in porridges. Strains used for these experiments, D7 and D12 as positive and K20 and T12 as negative controls, were they selected based on results of the present study?
Line 115, “with grams iodine” please explain how it was performed.
Line 135, explain why 37ºC was selected as growth temperature if strains were isolated from food matrices.
Lines 159-160, include these strains in a table with all strains used in the study.
Line 181, Table 1 shows all strains used and not “selected strains”. This table makes no sense. It should be removed.
Line 198, “as compared paired to controls” please rephrase for better understanding.
Line 202, LAB can be used all the text through instead of “Lactic acid bacteria”.
Figure 23, Time (Hour) “hours”.
Line 336, “The selected 9 potential probiotic strains” please revisit the “concept of probiotic”.
Line 353, define ALAB
Line 366, remove “sugar” it is twice.
Lines 390-393, the sentence should be reworded since the production of “bacteriocins” was not demonstrated in this study.
Lines 406-407, please reword the sentence “in the preparation fermented porridges will not be effective as probiotics are said to be strain dependent” taking into account that probiotic character is strain dependent but not related with fermentative capacity.
Supplementary material
Check the way to designate subspecies in all the Tables: i.e. Lacticaseibacillus paracasei subsp. Paracasei it should be written in this way Lacticaseibacillus paracasei subsp. paracasei
Comments on the Quality of English LanguageEnglish should be checked. Some sentences need to be reworded for understanding.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe statical results in the figures are not clear. What do these letters represent?
Author Response
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Reviewer 2 Report
Comments and Suggestions for Authors
The revised ms has been greatly improved but there are still some pending issues that have not been addressed or properly addressed.
- The new title fits much better with the content and aim of the study, but I would suggest a minor change to increase its impact: substitute “assay” by “capability/ability”
Amylolytic (assay) ability and performance of probiotic strains in a controlled sorghum fermentation system
- Regarding introduction, main subject of the study is “sorghum fermentation” by probiotic strains. Therefore, it is not appropriate to start with the definition of probiotics. Instead, the narrative should start highlighting the role of LAB in food fermentations, and following with the fact that some LAB are probiotics.
I strongly suggest removing the sentences in lines 28-29 and start highlighting “the role of LAB in food fermentations”, followed by “some probiotics are LAB”. The message in the sentence “They are normally inhabitants of a healthy gut” is not correct. Better to delete it.
Line 43, delete “the” and include “other substrates i.e. starch” as follows …. the it must be obtained from other substrates i.e. starch, during fermentation….
Line 60, delete “Microorganims” start the sentence with “LAB”
Line 62, as indicated in the previous review, it is not correct to say “Lactiplantibacillus plantarum, a commonly used probiotic strain”. If you mean a “strain” reference should be provided (i.e. DSM 324). But in coherence with the rest of the sentence I would suggest rephrasing as follows: “Probiotic strains belonging to Lactiplantibacillus plantarum commonly used in the food industry, have frequently been isolated from traditional cereal-based…. “
Lines 68-69, “There is also a possibility of producing high energy, drinkable food products that could be consumed by younger children if the probiotic bacteria have amylolytic abilities.”
I would suggest an alternative sentence that fits better in the wording:
“Younger children could benefit from high energy, drinkable food products derived from starchy substrata (i.e. sorghum) fermentation by amylolytic probiotic strains”.
Line 77, change “in a possible use” by “for application”
Line 84, change “identified” by “determined”
Lines 196-197, “The amylase enzyme was further confirmed through PCR amplification for Strains D7 and D17 which were successfully amplified. The results of PCR amplicons for the detected gene are demonstrated in supplementary Figure S2 which was positive for amylase”
Line 299, the sentence “Some of the properties of probiotics is that the strains should survive processing conditions and be a lactic acid producer, “ is not correct as it is. Authors probably mean “The applicability of probiotic strains in functional food development requires to survive processing conditions and low pH derived from lactic acid production”
Line 345, Lactobacillus fermentum it was renamed as Limosilactobacillus fermentum. It should read Limosilactobacillus fermentum (former Lactobacillus fermentum)
Line 348, 4 probiotic … “strains” is missing.
Line 371, “…. are completely inhibited to prevent diseases caused by…” it cannot be totally guarantied. Better to say “would help to prevent”
Line 374, “This findings in line with the work conducted by [14], [33]. [33], also reported…. ” please check the sentence.
- Supplementary material
Table S1, “origin” column should be deleted since origin of strains is a previous study.
Figure S1, legend should read as follows:
Figure S1: Fermentation products showing the effect of amylase positive strains D7 and D12 on sorghum gruel.
Figure S2, legend should read as follows:
Figure S2: Agarose gel electrophoresis showing positive results for PCR amplification of phes gene in strains D7 and D12.
Tables S3, S4, S5, correct 24hours, 8hours
Comments on the Quality of English LanguageEnglish language should be professionally checked
Author Response
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