Optimal Production of Ganoderma formosanum Mycelium with Anti-Melanogenic Activity

Round 1

Reviewer 1 Report

The manuscript ID fermentation-2294726:  Liu et al. entitled “Optimal production of Ganoderma formosanum mycelium with anti-melanogenic activity” describes optimization of the most favorable conditions for production mycelium endemic mushroom Ganoderma formosanum as well as the anti-melanogenic activity of extracts in vivo and in vitro

 My suggestion is to make minor changes

-       Line 51: Indicate which species of Aspergillus produces kojic acid

-       Line 237: In vitro in italic font

-      Line 310: review the literature and indicate whether the GFE are comparable with extracts from mushrooms, mycelia of other types of mushrooms

In my opinion, the manuscript is well written, the data presented in this are new and interesting, and my suggestion is to accept it for publication in Fermentation.

Author Response

Reviewer 1

• Line 51: Indicate which species of Aspergillus produces kojic acid

We appreciated this valuable suggestion. We add the information of the species of Apergillus which were reported producing kojic acid. The manuscript was corrected accordingly. (Line 52-53)

• Line 237: In vitro in italic font

We corrected in vitro and in vivo in italic font. (Line 255, 274)

• Line 310: review the literature and indicate whether the GFE are comparable with extracts from mushrooms, mycelia of other types of mushrooms

We appreciated this valuable suggestion. We searched and added some mushrooms extracts with anti-melanogenic activity. (Line 344-351)

Reviewer 2 Report

The manuscript is about the optimisation of the medium and culture conditions of the fungus Ganoderma formosanum for the production of mycelium with anti-melanogenic activity. Overall the content and experiments are clear and precise. The conclusions are in line with the results obtained. But some minor considerations should be take into account:

More information on other melanin extraction agents, compounds or methods could be provided. Moreover, it would change the proposed objective of the article, as it does not focus on finding the extraction conditions but on the growing conditions (line 71).

Hasn't cultivation or fermentation under liquid conditions been considered? I wonder if the agar has no effect on the extraction process of the GF extract?

Why Duncan test is applied instead HSD Tukey for multiple comparisons? Duncan’s test raises the type I error rates, and I think this would have to be reconsidered as these are in vivo trials, with the strong implication that they could have with false positives.

Consideration could be given to growing the fungal mycelium at pH 5.5 versus pH 7, as the difference in biomass (Figure 1A) compensates for the small difference in tyrosinase inhibition (Figure 1B).

>Line 41: melnin?

Author Response

Reviewer 2

• More information on other melanin extraction agents, compounds or methods could be provided.

We appreciated the suggestion. We added citations related to improve our manuscript according to your suggestion. (Line 129-130)

• Moreover, it would change the proposed objective of the article, as it does not focus on finding the extraction conditions but on the growing conditions (line 71).

We appreciated this important suggestion. This study aims to investigate the. composition of the ingredients used in liquid fermentation culture to afford Ganoderma formosanum mycelia for improving the anti-melanogenic activity. We correct the description of Line 71-72 to be “The objective of this study is to optimize to optimize the liquid fermentation culture medium composition for improving the anti-melanogenic activity of GF mycelium extracts by using one-step-at-a-time method.” (Line 77-79)

• Hasn't cultivation or fermentation under liquid conditions been considered? I wonder if the agar has no effect on the extraction process of the GF extract?

The GF mycelia used in this study was obtained from liquid fermentation.

• Why Duncan test is applied instead HSD Tukey for multiple comparisons? Duncan’s test raises the type I error rates, and I think this would have to be reconsidered as these are in vivo trials, with the strong implication that they could have with false positives.

We appreciate the suggestion about the statistical analysis methods. We generally used Tukey post hoc test for 2 groups with even numbers. In this study, there are more than 2 groups with variant numbers in analysis. Therefore, we used Duncan test in this study.

• Consideration could be given to growing the fungal mycelium at pH 5.5 versus pH 7, as the difference in biomass (Figure 1A) compensates for the small difference in tyrosinase inhibition (Figure 1B).

Thank you for the comment. We will also study on the samples from pH 5.5 in the future study.

• Line 41: melnin?

It should be “melanin”. We corrected this typo. (Line 41)