Selection of Saccharomyces cerevisiae Isolates from Helan Mountain in China for Wine Production
Round 1
Reviewer 1 Report
In general it is a great job. However, I attach some comments to improve the quality of the manuscript.
1. S. cerevisiae should be italicized in the abstract and in some parts of the text
2. Figure 1 does not have a title. 7A and 7B.
3. In 2.3.1 Some yeast strains that precipitate easily can cause interference in the reading (microplate) compared to those that do not precipitate. The authors can explain if they incorporated any method to control this.
Results and discussion
4. Table 2 is not fully appreciated. What does it mean A: [41]; B: [49]; C: [50] D: [51].
5. Although it is not the objective, the authors can report and discuss the non-Saccharomyces strains found. Many of these strains can have good fermentation ability and give promising regional characteristics.
6. In 2.4 explain better: The final wines were added with 50 mg/L SO2 and named as SCw and FSCw, respectively.
7. Very confusing is the fact that the authors discuss SCw in a comparative way but do not show a table or figure with these data.
8. You must explain the sensory evaluation again. It has two figures and you do not explain them in detail. Match the attributes to compare. In figure 7A it has 5, and in figure 7B has 6. Perhaps it is not the best way to compare in this case due to the large number of samples.
9. In several parts of the article the authors mention that they want to obtain a strain with regional characteristics, however, the selection and comparison method was based in some cases on the comparison with the FSC strain, which is an introduced strain, so they are going to finding a strain similar to the control, authors can emphasize the regional characteristics they are looking for in the wine
Author Response
Reviewer 1:
In general, it is a great job. However, I attach some comments to improve the quality of the manuscript.
Response: Thanks for your time and sincere efforts. We also appreciate the Editors and Referees for their valuable suggestions and comments.
- S. cerevisiae should be italicized in the abstract and in some parts of the text.
Response: S. cerevisiae in the paper had been italicized.
- Figure 1 does not have a title. 7A and 7B.
Response: The title for Figure 1, 7A and 7B had been added.
- In 2.3.1 Some yeast strains that precipitate easily can cause interference in the reading (microplate) compared to those that do not precipitate. The authors can explain if they incorporated any method to control this.
Response: Plates were incubated at 28 ℃ for 48 h and microshocked until turbid to reduce the interference of precipitate in the reading before measuring the absorbance at 600 nm using a Multifunctional microplate reader.
Results and discussion
- Table 2 is not fully appreciated. What does it mean A: [41]; B: [49]; C: [50] D: [51].
Response: Sorry for our carelessness, Table 2 is reorganized to present a better appreciation effect. In addition, A, B, C, and D indicated the corresponding reference: [41], [42], [43], [44] in the revision.
- Although it is not the objective, the authors can report and discuss the non-Saccharomyces strains found. Many of these strains can have good fermentation ability and give promising regional characteristics.
Response: The non-Saccharomyces strains found were not discussed in this paper, because the research on them have been completed and will be presented in another manuscript.
- In 2.4 explain better: The final wines were added with 50 mg/L SO2 and named as SCw and FSCw, respectively.
Response: “The final wines were added with 50 mg/L SO2 and named as SCw and FSCw, respectively” have been changed into “The final wines were added with 50 mg/L SO2. Wines fermented by 14 S. cerevisiae isolated strains and FSC were named as SCw and FSCw, respectively.
- Very confusing is the fact that the authors discuss SCw in a comparative way but do not show a table or figure with these data.
Response: SCw indicated the wines fermented by 14 isolated S. cerevisiae strains.
- You must explain the sensory evaluation again. It has two figures and you do not explain them in detail. Match the attributes to compare. In figure 7A it has 5, and in figure 7B has 6. Perhaps it is not the best way to compare in this case due to the large number of samples.
Response: The number of wine samples are too many to clearly present in one radar plots, so the 15 samples were presented on two radar plots (Figure 7A and 7B). In addition, all wines exhibited aromas characterized by red fruity, black fruity, floral, green, and spices, with some samples (F9-23w, SXY-4w, and MXY-19w) also showing varying degrees of yeasty notes. Therefore, we grouped the sensory evaluation of these three samples together in Figure 7B, which includes an additional yeasty indicator compared to Figure 7A.
- In several parts of the article the authors mention that they want to obtain a strain with regional characteristics, however, the selection and comparison method was based in some cases on the comparison with the FSC strain, which is an introduced strain, so they are going to finding a strain similar to the control, authors can emphasize the regional characteristics they are looking for in the wine.
Response: The research aim is to obtain some original S. cerevisiae with original regional characteristics. The introduced FSC strain was the most popular for producer in China, so we used it as the reference strain. In fact, we are under consideration in this aspect.
Reviewer 2 Report
Comments for author File: 
Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
The paper Hu and his collaborators proposed is very interesting for the topic of Saccharomyces cerevisiae strains as a tool in wine fermentation. They present a very well experimented method for the identification of strains suitable for wine production, in terms of oenological properties, low H2S production, suitable flocculation ability, L-malic acid reducing ability, and content of polyphenol, anthocyanin, tannin, terpenes. Using their strategy for the selection of indigenous S. cerevisiae strains for wine fermentation, they isolated and identified 199 strains from the vineyards and spontaneous fermentation must at the eastern foot of Helan Mountain in China. Among them, 14 strains exhibited excellent tolerance abilities to sugar, SO2, and ethanol and one strain present the best abilities required for large-scale wine fermentation.
The work is well-presented and structured. The experiments have been very well designed and carried out and the conclusions achieved based on the experimental data are well justified and very useful. The methods used in this study are specific and the experiments are clearly explained.
I accept the publication of the manuscript in the present form, with the special mention that the species name should be written in all document in italic font.
Author Response
Reviewer 3:
The paper Hu and his collaborators proposed is very interesting for the topic of Saccharomyces cerevisiae strains as a tool in wine fermentation. They present a very well experimented method for the identification of strains suitable for wine production, in terms of oenological properties, low H2S production, suitable flocculation ability, L-malic acid reducing ability, and content of polyphenol, anthocyanin, tannin, terpenes. Using their strategy for the selection of indigenous S. cerevisiae strains for wine fermentation, they isolated and identified 199 strains from the vineyards and spontaneous fermentation must at the eastern foot of Helan Mountain in China. Among them, 14 strains exhibited excellent tolerance abilities to sugar, SO2, and ethanol and one strain present the best abilities required for large-scale wine fermentation.
The work is well-presented and structured. The experiments have been very well designed and carried out and the conclusions achieved based on the experimental data are well justified and very useful. The methods used in this study are specific and the experiments are clearly explained.
I accept the publication of the manuscript in the present form, with the special mention that the species name should be written in all document in italic font.
Response: Thanks for your affirmation and constructive suggestions. We deliver our sincere gratitude towards the reviewers for their efforts and valuable advice on our manuscript which we believe greatly improved our manuscript. In addition, the species name in all document have been written in italic font.
