Molecular Identification and Biochemical Characterization of Novel Marine Yeast Strains with Potential Application in Industrial Biotechnology

Round 1

Reviewer 1 Report

The paper, for me, is fine.

May be in another work, one can look if these strains are halophilic, halotolerant or mesophilic but found accidentally in such environment.

Please, take care of subscripts.

Also, units are over-repeated.

Author Response

Dear Reviewer,

I would like to thank you for evaluating this work as well as for your recommendations that have improved this manuscript.

Please find the answers below each of your question/suggestion (in bleu color)..

Please, take care of subscripts., also, units are over-repeated.

All subscripts and units were checked and modified in the text.

Suggestion: May be in another work, one can look if these strains are halophilic, halotolerant or mesophilic but found accidentally in such environment.

Thank you for your suggestion, we planned to study the salinity effects on yeast growth of these selected strains.

Sincerely yours with best regards,

Prof. Saloua Sadok

Head of Laboratory Blue Biotechnology and Aquatic Bioproducts (B3Aqua)

Institut National des Sciences et Technologies la Mer (INSTM)

28 Rue 2 Mars 1934, Carthage Salammbô – 2025 Tunisia

Tel: 00216 71735848; Fax: 00216 71732622.

Corresponding author E-mail: [email protected]

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, five marine yeast strains were isolated, molecularly identified and biochemically characterized. The research is somewhat lacking in novelty.

Some other points are outlined below:

1 Lines 147 - 156, A detailed oven temperature program should be listed for fatty acid content analysis.

2 Why did the authors choose to use human embryonic kidney cells (HEK293) for the cytotoxicity assay?

3 Table 4, “South Sea of chine” should be “South China Sea”.

4 Table 5, column “Mineral”,”Ash”,”Carbohydrate”..., “,” should be “.”?

5 The contents of the column "fatty acid" in Table 5 and Figure 2 are somewhat duplicated, and it is recommended to keep only one.

6 Figure 3A, horizontal axis label should be “0, 0.12, 0.25, 0.5, 1”? in fig.3B, the first rows and third rows are T=0, the second rows and fourth rows are T=24?

Author Response

Dear Reviewer,

I would like to thank you for evaluating this work as well as for your recommendations that have improved this manuscript.

Please find the answers below each of your question (underlined)..

• Lines 147 - 156, A detailed oven temperature program should be listed for fatty acid content analysis.

Specification of the oven temperature for fatty acid analysis were added in the text (L152-153).

• Why did the authors choose to use human embryonic kidney cells (HEK293) for the cytotoxicity assay?

We chose HEK293 cells for the simple reason that it is the most used eukaryotic model and the closest to yeast. With this model we can mimic the process of decomposition and use of marine yeast in humans and therefore confirm the non-toxicity of our product for human cells and thus the application of our products for useful purposes in pharmacy and food. Also, HEK293 cells are embryonic kidney cells which are immune and it is the most used model to test the toxicity.

• Table 4, “South Sea of chine” should be “South China Sea”

As you suggest modification was made in table 4.

• Table 5, column “Mineral”,”Ash”,”Carbohydrate”..., “,” should be “.”?

Ash, mineral and carbohydrate were part of the full biochemical composition in this study. In our vision, it was indispensable to have an idea about those parameters in aims to handle correctly those strain especially for fermentation, feed application and enzyme production.

• The contents of the column "fatty acid" in Table 5 and Figure 2 are somewhat duplicated, and it is recommended to keep only one.

As you recommend, we decide to keep only the table which resume all the biochemical composition.

• Figure 3A, horizontal axis label should be “0, 0.12, 0.25, 0.5, 1”? in fig.3B, the first rows and third rows are T=0, the second rows and fourth rows are T=24?

For the horizontal axe in fig3.A, values (0, 0.12, 0.25, 0.5, 1) represent the quantity of yeast strain added to the culture media. For the fig 3.B, as mentioned in text, Analysis of HEK293 cells morphology in untreated (a) and treated HEK293 cells (b) with the marine yeast 1 (TaTun15), 2 (RmTun15), 3 (YlTun15), 4 (DhTun2015), and 5 (CtTun15) after 24 h of incubation. We revise the fig title to make it clearer.

Sincerely yours with best regards,

Prof. Saloua Sadok

Head of Laboratory Blue Biotechnology and Aquatic Bioproducts (B3Aqua)

Institut National des Sciences et Technologies la Mer (INSTM)

28 Rue 2 Mars 1934, Carthage Salammbô – 2025 Tunisia

Tel: 00216 71735848; Fax: 00216 71732622.

Corresponding author E-mail: [email protected]

Author Response File: Author Response.pdf