Effect of Novel Penicillium verruculosum Enzyme Preparations on the Saccharification of Acid- and Alkali-Pretreated Agro-Industrial Residues

Round 1

Reviewer 1 Report

I think that this paper is improved

Author Response

Dear Reviewer, 

Thank you very much for you comment.

Best regards,

Dr. Alexandra Rozhkova

Reviewer 2 Report

Generally, compared to the last version, the quality of this version improves a lot. The authors addressed most issues proposed by the reviewers. Some minor issues:

1. Table 1: the authors didn't mention where they got these composition data or what methods they used to analyze the composition.
2. Figures 1-3: Please provide figures with higher resolution.

Author Response

Point 1: Table 1: the authors didn't mention where they got these composition data or what methods they used to analyze the composition.

Response 1: Relevant analytical methods have been added below Table 1 in the Materials and Methods section.

Point 2: Figures 1-3: Please provide figures with higher resolution.

Response 2: Please, find Figures 1-3 with adjusted resolution (to 500 dpi) in the final version of Manuscript.

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

Journal: Agronomy

Manuscript: agronomy-883516-v1

Title: Effect of Acid and Alkaline Pretreatments on the Enzymatic Saccharification of Different Agro-Industrial Residues by Novel Penicillium verruculosum Enzyme Preparations

This paper deals with the evaluation of two types of pretreatments (in acidic or alkaline conditions) ir order to increase the enzymatic susceptibility of three lignocellulosic materials of residual nature (sugarcane bagasse; soybean husks; palm empty fruit bunches) using in situ enzymes. The topic may be interesting for the readers of Agronomy, but the paper has some important issues:

1. Lines 93-98 of introduction section are conclusions of this work, and must be removed of this section.
2. Table 1 is not necessary; its information is redundant with that the text.
3. Data about lignocellulosic raw materials composition are essential.
4. Pretreatments were carried out in single, arbitrarily fixed conditions, without justification. If one of the main objectives of this work is to evaluate the effect of the pretreatments, more conditions should have been evaluated.
5. Data about pretreatments performance are essential: solid yields and composition of solid phases (at least). Without these data, it is impossible to evaluate this work and the enzymatic hydrolysis.
6. Figures 1, 2 and 3 are neither logical nor useful for the readers. These figures show the time course of glucose release in enzymatic hydrolysis, but for a normal comparison the figures must be modified, grouping in the same figure the data for 3, 24 and 48 h, not in different figures. The same must be applied to the rest of figures.

Reviewer 2 Report

This manuscript can't be accepted for the following reasons:

1. Lack of Novelty

• All three substrates have been extensively investigated before.
• Two pretreatment (NaOH and H2SO4) methods have been extensively investigated before.
• Acid/Alkaline + saccharification has been extensively investigated before.
• The authors mentioned the penicillium verruculosum is novel but didn't give any background about it in the manuscript.

2. In the Method section, please provide the composition of the three substrates. Although the authors provide the literature data in the introduction, the composition of substrates from different sources vary a lot. The authors should provide their own data.

3. The workload is not enough.

4. When comparing the treated materials with the untreated materials to evaluate the pretreatment performance, the authors should calculate all yield data based on the mass of untreated samples. The composition of the substrate changes a lot after acid or alkaline pretreatment. For example, lignin might be partially removed during the pretreatment. To make a fair comparison, the authors should use the same basis.

5. The authors reviewed a lot of literature in the discussion section but didn't provide any substantial insights.

Figure 1: the highest amount is less than 40g/L, why did the authors set the scale of y-axis 0-100 g/L?