Integration of Corn and Cane for Ethanol Production: Effects of Lactobacilli Contamination on Fermentative Parameters and Use of Ionizing Radiation Treatment for Disinfection

Round 1

Reviewer 1 Report

Line 111, "which corn was the only carbohydrate source," ...authors should have information about composition of corn, such as proximate analysis. Also the composition of cane should be analyzed too

- section 2.2.3 it will be better if authors add diagram for figure about this radiation set up

- 167, 6 m/min...so what is the flow rate of liquid sample?

-Table 2 authors should indicated what is the sampling time to measure residual sugars

- 215-216, this assumption, authors should do sampling with multiple time to confirm this 

-Section 3.2.1 authors should determine the initial concentration of contaminated bacteria in the sample before treatment

- 272-273 "the yeast in the contaminated treatment." ..did authors measure concentration of contaminated yeast?

- 289-291 please recheck this sentence...ethanol decrease ethanol yield?

- 337-339 please explain why authors selected this dose for treatment. please review other related work if any tested with higher or lower dosage

- 356, it will be more beneficial to readers if authors also provide the operation cost for this study too. or just electricity cost

Author Response

Dear reviewer, thank you very much for your comments and for helping improve the quality of the manuscript. We went through your comments and made the following modifications as you suggested:

• Line 111, "which corn was the only carbohydrate source," ...authors should have information about composition of corn, such as proximate analysis. Also the composition of cane should be analyzed too
•  in table 1 we provide the fermentable sugars and mannitol + glycerol content of the energy cane juice, which are parameters of interest in this study. We have now added more information about the composition of the corn in the materials section (lines 98-99)

• 167, 6 m/min...so what is the flow rate of liquid sample?
• Thanks for your comment. The electron accelerator was for a pilot scale, so we did the treatment in batches. We rewrote the sentence (lines 164-168) and added a fluxogram in Figure 1 to make it more clear to the reader how the irradiation process was carried out in this study. 

• -Table 2 authors should indicated what is the sampling time to measure residual sugars
• We have added in the table caption that the results indicated in the table were at the end of the fermentation, at 24 hours (line 209).
• 215-216, this assumption, authors should do sampling with multiple time to confirm this
• Thanks for your comment. We have removed this assumption as we do have the data to confirm it and it is not relevant to the scope of the study.   
• Section 3.2.1 authors should determine the initial concentration of contaminated bacteria in the sample before treatment.
• This is shown in figure 4.
• 272-273 "the yeast in the contaminated treatment." ..did authors measure concentration of contaminated yeast?
• The yeast used in this study did not have contamination. We rewrote the sentence and it now says: (the yeast in the contaminated wort), to make it clear to the reader that the contamination is in the wort, not in the yeast.
• 289-291 please recheck this sentence...ethanol decrease ethanol yield?
• We rewrote this sentence to make it more clear (lines 287-289)
• 337-339 please explain why authors selected this dose for treatment. please review other related work if any tested with higher or lower dosage
• We have added in the materials and methods that this dose was selected based on Calegari et al. (2023) results with sugarcane juice (Lines 170-171). We also mention in lines 352-357 that Calegari et al. tested different doses in another study. We added a sentence in the conclusions (lines 370-371) highlighting that a study to assess lower radiations should be performed.
• 356, it will be more beneficial to readers if authors also provide the operation cost for this study too. or just electricity cost
• Calegari et al. (2023) calculated the costs per cubic meter and we added a sentence and cited it in line 357.

Reviewer 2 Report

но и к развитию реального производства этанола в условиях возможности использования двух разных видов сырья (кукурузного крахмала и сахаросодержащего тростникового сока). Новинка не очевидна на первый взгляд. Фактически авторы пытаются предвидеть риски производства этанола в новых условиях и научно обосновать основные принципы и подходы к устранению этих рисков. Сильной стороной статьи является формулировка авторами узких мест цели: этанол можно получить в таких условиях, но не исключено, что процесс будет более затратным из-за необходимости замены традиционных антибиотиков ионизирующим излучением. Слабой стороной статьи являются политические аспекты введения. Очевидно,

Issues and comments to be addressed:

1. There are typos in the text, “?” is repeatedly consumed.

2. It is recommended to rewrite the first sentences of the introduction, indicating the continuation of the most interesting topic of obtaining ethanol using a mixture from two sources of raw materials. At the same time, exclude political motives.

3. References are given in the form of numbering and at the same time also occurs in the form of "Last name, year of publication." It is recommended to bring to uniformity.

4. В статье дважды говорится о возможности применения ионизирующего излучения: во введении и в разделе «3.2.3. Дезинфекция ионизирующим излучением» (ссылка Calegari et al. (2023)). Создается впечатление, что авторы заранее знали результат будущего исследования. Нам нужно изменить эту ситуацию.

Author Response

Dear reviewer, thank you very much for your comments and for helping improving the quality of the manuscript. We went through your comments and made the following modifications as you suggested:

Issues and comments to be addressed:

1. There are typos in the text, “?” is repeatedly consumed.

Thanks for calling attention to that. We went over the text and removed the “?”.

2. It is recommended to rewrite the first sentences of the introduction, indicating the continuation of the most interesting topic of obtaining ethanol using a mixture from two sources of raw materials. At the same time, exclude political motives.

we have removed that sentence as it was just an introductory sentence and was not relevant for the study.

3. References are given in the form of numbering and at the same time also occurs in the form of "Last name, year of publication." It is recommended to bring to uniformity.

We changed the references and used only numbers.

4. The article mentions the possibility of using ionizing radiation twice: in the introduction and in the section “3.2.3. Disinfection with ionizing radiation” (ref. Calegari et al. (2023)). It seems that the authors knew in advance the result of the future study. We need to change this situation.

 Calegari et al. studied it just for sugarcane juice, no studies had been performed yet with the mixture of corn and cane juice. We now added a sentence in lines 81-83, explaining that with more details. I hope it is more clear.

Round 2

Reviewer 1 Report

All comments were responsed and the revised manuscript is looked good now

Reviewer 2 Report

The authors corrected the article in accordance with the comments. Therefore, you can publish in the presented form.