Culture Age, Growth Medium, Ultrasound Amplitude, and Time of Exposure Influence the Kinetic Growth of Lactobacillus acidophilus

Round 1

Reviewer 1 Report

Title: Culture age, growth medium and ultrasound amplitude, and time of exposure influence the kinetic growth of Lactobacillus acidophilus

This interesting paper deals with food processing by ultrasound on the kinetic growth of Lactobacillus acidophilus. In my opinion, the article is well structured, many experimental methods have been used, and the results are clearly presented and discussed.

 

I think the article presents a valuable work that will be of high interest to the readers of the journal, as it presents novel approaches which still need to be further studied. I would suggest the article be published. 

One minor change that I would recommend is to change the title: Culture age, growth medium, ultrasound amplitude, and time of exposure influence the kinetic growth of Lactobacillus acidophilus 

Author Response

First of all, thanks for the comments and observations. The authors made the changes in the title according to the reviewer's suggestion.

Reviewer 2 Report

This manuscript is about a investigation of the influence of the growth medium, culture age, and ultrasound treatment on the kinetic parameters of L. acidophillus. Though the topic is not meaningless, the experimental design is simple, the discussion and conclusion are superficial. It could provide little useful information for readers in this field.

 

Other comments:

1.The usage and representativeness of Lactobacillus acidophilus (LA-5) were not explained.

2.It was not indicated how many replicates were used in each experiment.

3.Figures 2,3,4,5,6 and 7 --The experimental data and corresponding model prediction should be presented in the same figure.

4.Line 182, Cultures with a larger Lag phase require major fermentation times to achieve the require pH-- No pH data could be found in this section.

5.Line 147, L. acidophilus growth was quantified at the beginning and at the end of the fermentation period...-- How were the beginning and at the end of the fermentation determined?

6.Figure 4 and 7--It is inappropriate that most of the survival percentage are above 100%. 

Author Response

Response to Reviewer 2 Comments

First at all, thanks for the comments and observations, authors take all them in account to improve the manuscript.

1.The usage and representativeness of Lactobacillus acidophilus (LA-5) were not explained.

Lines 93-97 mentioned the application in industry and main bioeffects of LA-5.

2.It was not indicated how many replicates were used in each experiment.

the Statistical analysis is mentioned in line 167 and on lines 113, 127, 144 and 146 it is mentioned that the experiments were performed in triplicate.

3.Figures 2,3,4,5,6 and 7 --The experimental data and corresponding model prediction should be presented in the same figure.

Experimental data cannot be presented in the same figure because each figure corresponds to different experimental conditions. Figure 2 shows the effect of inoculum age on the growth curve of Lactobacillus acidophilus. Figures 3 and 4 evaluate the effect of sonication time on the growth curve and percentage survival of Lactobacillus acidophilus. While Figures 5, 6 and 7 show the effect of ultrasound amplitude on the growth curve, pH kinetics and biomass increase of Lactobacillus acidophilus.

4. Line 182, Cultures with a larger Lag phase require major fermentation times to achieve the require pH-- No pH data could be found in this section.

Line 186 the sentence was modified since in this part pH was not evaluated.

5.Line 147, L. acidophilus growth was quantified at the beginning and at the end of the fermentation period...-- How were the beginning and at the end of the fermentation determined?

Line 153 mentions the methodology used to quantify the growth of LA-5 at the beginning and at the end of the fermentation period, the determination was made by the MRS agar plate count methodology.

6.Figure 4 and 7--It is inappropriate that most of the survival percentage are above 100%.

A modification was made in Figures 4 and 7, survival percentage was changed by increase in biomass (%). The initial concentration was considered as 0% growth.

NOTE: The lines were moved by the addition of text in the introduction section.

 

Reviewer 3 Report

Dear Authors,

Please refer to the attached Word file with my comments. Thank you.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, All your comments have been considered to improve the quality of the manuscript. The authors remain attentive to any other observations.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

I personally think that limited improve has been made in the revision. For example, I cannot understand why experimental data cannot be presented in the same figure. This is an usual practice in modelling and has nothing to do with different experimental conditions. I still think that the experimental design is simple, the discussion and conclusion are superficial. It could provide little useful information for readers in this field.

Author Response

Dear reviewer,

The article has been improved and various changes have been made throughout it; the authors hope that these changes have improved its quality.

The OFAT approach is used in which one factor is changed at a time while other factors are kept constant. The appropriate input value of each factor is determined and kept consistent in the succeeding experiment.

Therefore, since the OFAT approach is carried out in a sequence of experiments, the results are shown in the same sequence. Putting the results together in a single graph could confuse the reader.

Reviewer 3 Report

Dear Authors,

Please refer to the attached Word file listing few additional minor editing comments/corrections for improvement.

Comments for author File: Comments.pdf

Author Response

Dear Reviewer, Thank you for your comments, each of them have been taken into account to improve the quality of the manuscript. The changes are highlighted in yellow in the document.

Round 3

Reviewer 2 Report

The revisions are almost acceptable

Author Response

Dear Reviewer, Thank you for your comments, each of them have been taken into account to improve the quality of the manuscript. The changes are highlighted in yellow in the document.