Versatility of Saccharomyces cerevisiae 41CM in the Brewery Sector: Use as a Starter for “Ale” and “Lager” Craft Beer Production
, Francesca Coppola 2, Francesco Letizia 1, Gianluca Albanese 1, Julian Karaulli 3, Mamica Ruci 3, Marco Pistillo 4, Giacinto Salvatore Germinara 4, Maria Cristina Messia 1, Mariantonietta Succi 1, Franca Vergalito 1, Patrizio Tremonte 1, Silvia Jane Lombardi 1 and Massimo Iorizzo 1,*
Round 1
Reviewer 1 Report
The manuscript “Versatility of Saccharomyces cerevisiae 41CM in the brewery 2 sector: use as a starter for the “Ale” and “Lager” craft beers production” evaluated the fermentative performance of S. cerevisiae 41CM yeast which was isolated from the vineyard environment, for Ale and Lager craft beers production on a laboratory scale. The overall experimental design is reasonable, and the data processing is also standardized. However, I have several concerns
1, Basic biological research should be carried out on the selected S. cerevisiae 41CM strain, including morphology, some physiological and biochemical indicators, etc. If there is such information, it is recommended to add it in the manuscript.
2, I found the sequence information of Saccharomyces cerevisiae strain 41CM in Genebank, it only showed the partial sequence (584bp) of large subunit ribosomal RNA gene. Although the whole genome sequence is not absolutely necessary for the publication of this manuscript, it is important to recognize a new strain. If there is any information in this part, it is recommended to upload it again.
3, It is very interesting that the metabolic substances and flavor substances of beer produced by several strains are different. However, how to explain the causes of these differences requires the author to rethink in the discussion section.
4, The ability of S. cerevisiae 41CM yeast strain to both ferment at 12 ° C and 20 ° 340 C and could be used both for the production of Ale beers and lager beers is a very interesting feature. But what is the reason and what factors cause the strain to play a role under the temperature conditions with large differences? The author needs to make some explanations in the discussion section.
Author Response
Reviewer 1
The manuscript “Versatility of Saccharomyces cerevisiae 41CM in the brewery 2 sector: use as a starter for the “Ale” and “Lager” craft beers production” evaluated the fermentative performance of S. cerevisiae 41CM yeast which was isolated from the vineyard environment, for Ale and Lager craft beers production on a laboratory scale. The overall experimental design is reasonable, and the data processing is also standardized. However, I have several concerns
1, Basic biological research should be carried out on the selected S. cerevisiae 41CM strain, including morphology, some physiological and biochemical indicators, etc. If there is such information, it is recommended to add it in the manuscript.
The Authors integrated the section (L. 62-64). In future will be carried out further morphological, physiological, and genetic characterizations.
2, I found the sequence information of Saccharomyces cerevisiae strain 41CM in Genebank, it only showed the partial sequence (584bp) of large subunit ribosomal RNA gene. Although the whole genome sequence is not absolutely necessary for the publication of this manuscript, it is important to recognize a new strain. If there is any information in this part, it is recommended to upload it again.
The Authors thank the reviewer for the suggestion. The complete genome of strain 41CM is currently unavailable, but one of our next activities will include this further genotypic characterization.
3, It is very interesting that the metabolic substances and flavor substances of beer produced by several strains are different. However, how to explain the causes of these differences requires the author to rethink in the discussion section.
The Authors integrated the discussion and added a reference n. 36 (L. 323-326).
4, The ability of S. cerevisiae 41CM yeast strain to both ferment at 12°C and 20°C and could be used both for the production of Ale beers and Lager beers is a very interesting feature. But what is the reason and what factors cause the strain to play a role under the temperature conditions with large differences? The author needs to make some explanations in the discussion section.
The Authors integrated the discussion (L. 287-290; 323-326).
Reviewer 2 Report
In this manuscript, S. cerevisiae 41CM isolated from a vineyard was tested for Ale and Larger beer brewing, and compared with commercial yeasts. It is helpful for the new yeast starter development. I think it can be accepted for publication after some clarifications and revisions.
1. Why were the yeast starters cultured in YEPD broth, not in wort directly?
2. The yeasts viability was evaluated using WL nutrient agar medium (line 78), then how to control the inocula at 106 yeast cells/mL(line 93)?
3. “3.1. Fermentative kinetics”, I think it just “the changes of pH, ethanol and yeast amount during fermentation”, not the kinetics, because rates of growth, media consumption and ethanol production were not calculated.
4. Figure caption should be presented in the bottom of figure 1, and the lines should be designated for ethanol or for pH.
5. Check the references or grammar errors.
For example:
(1) Line 92, add comma between “S-04 Ale” and “and”. Add “, respectively” after “W-34/70 Lager”.
(2) Line 154, “has gradually decreased” should be “gradually decreased”.
(3) incomplete references 4, 9, 29.
Author Response
Reviewer 2
In this manuscript, S. cerevisiae 41CM isolated from a vineyard was tested for Ale and Larger beer brewing and compared with commercial yeasts. It is helpful for the new yeast starter development. I think it can be accepted for publication after some clarifications and revisions.
- Why were the yeast starters cultured in YEPD broth, not in wort directly?
Starter cultures were grown in YEPD broth to optimize cell growth; once grown, the culture was centrifuged, and the pellet was washed. It was then resuspended in beer wort and was then inoculated at a final concentration of 106 cells/mL (L. 72-79).
- The yeasts viability was evaluated using WL nutrient agar medium (line 78), then how to control the inocula at 106yeast cells/mL (line 93)?
The Authors integrated the section (L. 80-82).
- “3.1. Fermentative kinetics”, I think it just “the changes of pH, ethanol and yeast amount during fermentation”, not the kinetics, because rates of growth, media consumption and ethanol production were not calculated.
The title and figure were changed considering also the suggestions of the third reviewer (L. 158;178-179).
- Figure caption should be presented in the bottom of figure 1, and the lines should be designated for ethanol or for pH.
The Authors moved the caption at the bottom of Figure 1 and modified the figure/caption as suggested by the third reviewer (L. 178-179).
- Check the references or grammar errors.
Done.
For example:
(1) Line 92, add comma between “S-04 Ale” and “and”. Add “, respectively” after “W-34/70 Lager”.
Done (L. 100-102)
(2) Line 154, “has gradually decreased” should be “gradually decreased”.
Done (L. 163)
(3) incomplete references 4, 9, 29.
Done.
Reviewer 3 Report
The manuscript “Versatility of Saccharomyces cerevisiae 41CM in the brewery 2 sector: use as a starter for the “Ale” and “Lager” craft beers production” submitted by Testa et al exposes the fermentative aptitudes of a yeast strain isolated from vineyard S. cerevisiae 41CM.
The work is within the scope of the journal and is very interesting and pertinent, since it investigates the characteristics of lager and ale beers fermented with alternative yeasts to commercial ones, isolated from natural environments, allowing brewers to counter with new strains that provide characteristics distinctive to their products.
The work is concise, concrete, with clear objectives and results in accordance with the stated objectives.
This referee considers that the work is of good scientific quality and that it is in a position to be published.
Just a few minor comments:
1) At the end of the introduction, authors claim that the strain 41CM was “selected for its good technological properties and 64 its capacity to ferment at low temperatures” and they refer to a prior published paper where they approach the study of 124 strains. It should be interesting if authors give a little more the information and deepen the justification of the strain selection (i.e.: Hydrogen Sulfide (H2S) Production, flocculation, etc.).
2) It would be desirable for the authors to provide a little more information on the elaboration of the used wort (type of malts used and hops).
3) in Figure 1 it should be noted that the continuous lines correspond to ethanol and that the dashed lines correspond to pH.
4) Saccharomyces cerevisiae in the title should be in italics
5) the language must be revised
Author Response
Reviewer 3
The manuscript “Versatility of Saccharomyces cerevisiae 41CM in the brewery 2 sector: use as a starter for the “Ale” and “Lager” craft beers production” submitted by Testa et al exposes the fermentative aptitudes of a yeast strain isolated from vineyard S. cerevisiae 41CM.
The work is within the scope of the journal and is very interesting and pertinent, since it investigates the characteristics of lager and ale beers fermented with alternative yeasts to commercial ones, isolated from natural environments, allowing brewers to counter with new strains that provide characteristics distinctive to their products.
The work is concise, concrete, with clear objectives and results in accordance with the stated objectives.
This referee considers that the work is of good scientific quality and that it is in a position to be published.
Just a few minor comments:
1) At the end of the introduction, authors claim that the strain 41CM was “selected for its good technological properties and 64 its capacity to ferment at low temperatures” and they refer to a prior published paper where they approach the study of 124 strains. It should be interesting if authors give a little more the information and deepen the justification of the strain selection (i.e.: Hydrogen Sulfide (H2S) Production, flocculation, etc.).
The Authors integrated the section (L. 62-64).
2) It would be desirable for the authors to provide a little more information on the elaboration of the used wort (type of malts used and hops).
Done (L. 86-91).
3) in Figure 1 it should be noted that the continuous lines correspond to ethanol and that the dashed lines correspond to pH.
The Authors modified the figure and the caption (L. 178-179).
4) Saccharomyces cerevisiae in the title should be in italics
Done.
5) the language must be revised
The manuscript was revised by a native speaker English.
Round 2
Reviewer 1 Report
The author answered my concerns in the revised manuscript and I suggest accepting the publication
Reviewer 2 Report
The authors have revised the manuscript as suggested, and I think it can be accepted for publication.
Reviewer 3 Report
Manuscript was impoved according to this reviewer´a comment. In my opinion, it is alredy suitable for publication in Processes Journal.
