Round 1

Reviewer 1 Report

The present study evaluated the effect of starter cultures on pH and microbial population during table olive fermentation and determined the changes of Lactobacilli during fermentation by qPCR. This manuscript shows that the starter facilitates the safety of table olives in the industrial production of table olives. However, there are several vital issues did not clearly describe. It should be made a minor modification before considering to accept.  

 

1 In this study, the strains used for experimental fermentation were isolated from previous brine samples, so why not use commercial strains? Was W. anomalus F5.60.5 strain also isolated from previous brine samples? It should be clarified.

 

2 W. anomalus F5.60.5 strain is the main difference between L and LY groups, but in this present study, why is qPCR used to determine the relative abundance of Lactobacilli instead of W. anomalus F5.60.5? It should be provided more discussion.

 

3 The full name of strains, such as L. plantarum and W. anomalus, should be used when they first appeared in the manuscript. Moreover, the format of the strain name in the present manuscript needs to be checked and confirmed.

 

4 In Line 262, the result of qPCR can only show the relative abundance of Lactobacilli. There is no relevant data to prove that Lactobacilli play a dominant role in the whole fermentation process. It should be given more explanation or supplementary data.

Author Response

1 In this study, the strains used for experimental fermentation were isolated from previous brine samples, so why not use commercial strains? Was W. anomalus F5.60.5 strain also isolated from previous brine samples? It should be clarified.

Thanks for your comment. The yeast W. anomalus F5.60.5 strain was previously isolated from the brine of Sicilian table olive naturally fermented. Details about the F5.60.5 strain were included in the materials and methods section (line 86). In the present study commercial starter strains were not used because one of the main goals of the present study was to evaluate the effects of indigenous strains, as starters, on both microbiological and physico-chemical parameters of table olives produced at the industrial level.

2 W. anomalus F5.60.5 strain is the main difference between L and LY groups, but in this present study, why is qPCR used to determine the relative abundance of Lactobacilli instead of W. anomalus F5.60.5? It should be provided more discussion.

Thanks for your comment. The qPCR assay was applied to quantify only the lactobacilli population since it can be considered as a positive biomarker for table olives fermentation. In addition, our study demonstrated that the sample inoculated only with lactobacilli exhibited a more pronounced decrease of spoilage bacteria related to a quick and more pronounced reduction of pH, which assure the safety and quality of the final product (lines 277-281).

3 The full name of strains, such as L. plantarum and W. anomalus, should be used when they first appeared in the manuscript. Moreover, the format of the strain name in the present manuscript needs to be checked and confirmed.

 Thank you for the suggestion. We used the full name of the species Lactiplantibacillus plantarum and Wickerhamomyces anomalus in the introduction section (lines 55 and 56) whereas reported the abbreviation L. plantarum and W. anomalus through the text.

4 In Line 262, the result of qPCR can only show the relative abundance of Lactobacilli. There is no relevant data to prove that Lactobacilli play a dominant role in the whole fermentation process. It should be given more explanation or supplementary data.

Thanks for your comment. In the present study, both culture-dependent and -independent (qPCR) techniques, showed the dominance of the lactobacilli, in both brine and olives samples, till the end of the fermentation process. In addition, the more pronounced reduction of pH, in L brine samples rather than LY and control samples, suggests the dominance of lactobacilli through the fermentation process. In fact, LY samples maintained a constant pH value of 4.17 till the end of the process, while the L fermentation exhibited a lower pH value.

Reviewer 2 Report

Comments for author File: Comments.pdf

Author Response

General Notes:

• An acronym must be explained the first time it is used. Once explicit, however, there is no need to repeat the explanation each time, otherwise, there is no point in using the abbreviation:
  • For qPCR, made explicit at R55, the explanation is also repeated at R64, R120, R186, and R298, while in the abstract the acronym is used without explaining what it is (R17).
  • For IOOC, made explicit at R28, it is also repeated in full at

 

Thanks for your comment. We made the corrections through the text as you suggested.

Since the chapter "Conclusions" is rather short, consider putting it at the end of the chapter "Discussions" as the last paragraph, or expand it.

Thanks for your suggestion. We included the conclusions in the discussion section.

 

• At the plagiarism check, the sentence at R108 'Results were expressed as log10 CFU/mL for brine and log10 CFU/g 108 for olive samples and standard deviation' is plagiarised. In my opinion, it can also remain so, as it is a sentence in the chapter "Materials and Methods" that does not detract from the merit of others, but I have a duty to point this out in the general report and the editor must

Thank you for the accurate correction.

Specific Comments:

R3 Add “an” (industrial scale).

Thanks for the suggestion. We included “an” in the title.

R25 The acronym LAB can have several meanings, make the meaning explicit or use the meaning in full directly as a "keyword".

Thanks for the suggestion. We both included the meaning among keywords and provided the full meaning of “LAB” in the text.

R28 The full name lacks "Oil".

Thanks for the suggestion. We added it.

R55 Remove "the".

Thanks for the suggestion. We applied the correction.

R60 "Deal with", not "deal at"; add "the" olive microbiota.

Thanks for the correction. We applied the correction.

R62 Replace "was" with "is".

Thanks for the suggestion. We replaced it.

R97 Explain the meaning of "LAB", if not already done in the keywords.

 Thank you for the suggestion. We both included the meaning among keywords and provided the full meaning of “LAB” in the text.

R154 Consider writing the results shown in the table in a smaller font because as they are shown, the last digit and its superscripts are always on the next line, creating confusion when reading. Alternatively, you can use a larger table that projects beyond the left margin (such a layout is usually possible).

Thanks for the suggestion. We reduced the font.

R165 What is the significance of this sentence? Does not the regulation require them to be searched? Or are they looked for but must not be there? In the second case, rewrite the sentence more clearly.

Thank you for your comment. We modified the sentence clarifying the meaning as you suggested (lines 176-183). The detection of both spoilage and foodborne pathogens was done by culture-dependent analysis according to the current regulation.

 

R192 A value is missing: R2 and E were 99.9 and? Especially if you write 'respectively' after it.

Thanks for the comment, we corrected the sentence as you suggested (lines 209,210).

R193-R195 Up to now 'Logarithm' has been abbreviated to 'log', whereas in these lines and in Table 3 use 'Log'. Always use the same form or explain the difference.

Thanks for the suggestion, we leveled up the “logarithm” abbreviation, reporting “log” through the text.

R212 Add 's' to 'standardise'.

Thank you for the correction, we modified it.

R213 Change "Allow" to "Allowing".

Thank you for the correction, we modified it.

R215 Replace "its" with "their" (ecological versatility).

Thank you for the correction, we modified it.

R216 Add "a" or "the" stressful environment, or change "environment" to plural.

Thank you for the correction, we modified it.

R244 Add "the" (selected starter cultures)

Thank you for the correction, we modified it.

R245 "In accordance with" not "to". Remove the comma after "strains".

Thank you for the correction, we modified it.

R248 Add "a" (starter).

Thank you for the correction, we modified it.

R255 Change to "with combined culture-dependent".

Thank you for the correction, we modified it.

R256 and R259 Add "the" (microbial community and microbial population).

Thank you for the correction, we modified it.

R261 The only one representative (remove "one").

Thank you for the correction. We removed it

R264 Add 'the' (olive surface).

Thank you for the correction, we modified it.

R282 Put the year in bold as in all other references.

Thanks, we corrected it.