Review Reports - Evaluation of Using Spent Mushroom Sawdust Wastes for Cultivation of Auricularia polytricha

Round 1

Reviewer 1 Report

Please indicate in the introduction the specific conditions for A. polytricha cultivation .

Indicate in the conclusions the measurable effect of research.

In abstract please provide full species name when using first time.

Author Response

Please indicate in the introduction the specific conditions for A. polytricha cultivation .

(Response: OK. We added one paragraph in the third section of introduction by red words)

Indicate in the conclusions the measurable effect of research.

(Response: OK. We added one paragraph in the last of conclusions by red words)

In abstract please provide full species name when using first time.

(Response: OK. Revised.)

Author Response File: Author Response.docx

Reviewer 2 Report

The aims and scopes and the objectives are well defined.

Introduction:

Should be improved! The potential application opportunities of these materials are wider even in mushroom production. More references are needed.

Materials and Methods:

Clear. What is reason that only C and N contents were measured? The other parameters are not important in mushroom production? More measurements are suggested to explain the results.

Result:

Clear. Probably it should contain the relationship between the results if any.

Discussion:

In the present form it is a long abstract, or just a summary of the results part. There are no explanations of the results, what can be the causes of these values, what are the relationships between the results etc. The significances of the results should be explored!

Reference list:

Should be improved, and should be in alphabetic order.

Author Response

The aims and scopes and the objectives are well defined.

Introduction:

Should be improved! The potential application opportunities of these materials are wider even in mushroom production. More references are needed.

(Response: OK. We added one paragraph in the second section of introduction by red words)

Materials and Methods:

Clear. What is reason that only C and N contents were measured? The other parameters are not important in mushroom production? More measurements are suggested to explain the results.

(Response: When mushroom hyphae grow, they secrete enzymes to decompose cellulose, hemicellulose and lignin in sawdust (these components belong to the C content), and then convert them into the carbon structure and carbohydrates of fruiting body. In addition, the N-contain components in the medium were decomposed into enzymes and protein in fruiting body. Therefore, the contents of C and N are the most need components for mushroom growth and development. During the mixing process of the medium ingredients, calcium carbonate is added to the culture medium to adjust the pH value. Wood chips and rice bran also contain minerals, but they are not the main research in this study.)

Result:

Clear. Probably it should contain the relationship between the results if any.

Discussion:

(Response: We added one paragraph in the third section of discussion by red words. “Mycelium growth and fruiting body production of Pleurotus spp. are affected by cellulose: lignin and carbon: nitrogen ratios [26]. SMSW does not produce good yield when it is used again in mushroom production as a substrate, due to subsequent utilization of nutrients by mycelium resulted in depletion of nutrients [27]. Compared with uncultivated sawdust, most of SMSWs (Table 1) with reduced carbon content but increased nitrogen content can still grow other mushrooms and increase the yield. In this study, the mycelial growth and yield of fungus did not show a high correlation with a specific carbon-nitrogen ratio.”)

Reference list:

Should be improved, and should be in alphabetic order.

(Response: The references are arranged in Arabic numeral order according to the instructions for authors.)

Author Response File: Author Response.docx

Reviewer 3 Report

Review manuscript agronomy-999479

“Evaluation of Using Spent Mushroom Sawdust Wastes for Cultivation of Auricularia polytricha”

General comments

Thus, my suggestion is major revision.

Specific comments

First section in the introduction – the last sentence is strange.

The description in section 2.4 is not clear to me. Was the spawn added only to the bottom and grew upwards? This measurement needs to be described clearer.

In section 2.5 it is stated that mean ± std is shown. However, in table 2 standard error is used. Be consistent.

Section 3. Result is misspelled

Table 1. Please do not start with the abbreviations – include the full name of the treatment in the table.

Reference 4 – why are the fungal strains in bold text?

Author Response

This manuscript concerns the reuse of spent mushroom substrate for further mushroom production. Spent mushroom substrate is produced in large amounts and it is beneficial to find uses for it. Thus, the topic is of interest for sustainable development of mushroom production. The scientific work is sound, however, the number of replicates needs to be stated more clear in the material section (n=6 throughout the study?). (Response: We revised to “Thirty replicate polyethylene bags were used for each medium formula, and six bags were randomly sampled during sampling.”) My main concern with this manuscript is that the authors only focus on C/N values and the differences in these values are quite small between the different treatments. Also other factors must be of interest in relation to production of fruiting bodies – how about phosphorus, trace metals, quality of the organic carbon etc. (Response: When mushroom hyphae grow, they secrete enzymes to decompose cellulose, hemicellulose and lignin in sawdust (these components belong to the C content), and then convert them into the carbon structure and carbohydrates of fruiting body. In addition, the N-contain components in the medium were decomposed into enzymes and protein in fruiting body. Therefore, the contents of C and N are the most need components for mushroom growth and development. During the mixing process of the medium ingredients, calcium carbonate is added to the culture medium to adjust the pH value. Wood chips and rice bran also contain minerals, but they are not the main research in this study. The difference in carbon and nitrogen content in the medium of single mushroom SMSW is relatively large, but the difference in carbon and nitrogen content in the medium composed SMSW of P. eryngii, P. ostreatus, and P. cystidiosus in different ratios (1:2, 1:1, 2:1) is small.) My suggestion is that the authors add a section about this in the discussion, which should be considerable more profound and detailed then the current section on hot water extract. (Response: Mycelium growth and fruiting body production of Pleurotus spp. are affected by cellulose: lignin and carbon: nitrogen ratios [26]. SMSW does not produce good yield when it is used again in mushroom production as a substrate, due to subsequent utilization of nutrients by mycelium resulted in depletion of nutrients [27]. Compared with uncultivated sawdust, most of SMSWs (Table 1) with reduced carbon content but increased nitrogen content can still grow other mushrooms and increase the yield. In this study, the mycelial growth and yield of fungus did not show a high correlation with a specific carbon-nitrogen ratio.) I would also suggest that the manuscript is subjected to professional language editing.

Thus, my suggestion is major revision.

Specific comments

First section in the introduction – the last sentence is strange.

(Response: In Taiwan, most of the SMSW will be added with chicken manure to make organic fertilizer, and a small part of the SMSW is placed in the mushroom production area and allowed to decompose and rot. Due to environmental protection issues, burning SMSW has been banned. We slightly modified this sentence.)

The description in section 2.4 is not clear to me. Was the spawn added only to the bottom and grew upwards? This measurement needs to be described clearer.

(Response: The mycelial growth rate was measured by measuring the length of the mycelium from the top to the bottom of the substrate when the mycelium was about to grow over the substrate, and then dividing by the incubation time. We change “After the mycelia fully colonized the substrate” to “When the substrate was about to fully colonize by the mycelia” in the sentence.)

In section 2.5 it is stated that mean ± std is shown. However, in table 2 standard error is used. Be consistent. (Response: Revised)

Section 3. Result is misspelled (Response: Revised)

Table 1. Please do not start with the abbreviations – include the full name of the treatment in the table. (Response: The abbreviation saves space in the table)