Antibacterial Activity of Green Synthesised Silver Nanoparticles on Saccharomyces cerevisiae

Round 1

Reviewer 1 Report

The Authors present a green synthesis of Silver Nanoparticles (AgNPs) to be used for a new cheap drug for  antibacterial infection especially for thoise that present an antibiotic- resistance. The Authors present neither physical-chemical characterization of the Silver nanoparticles nor those of surnatant.  There is no discusssion of how these AgNPs must be employed in the new drug they quote. The toxicity of AGNPs they report can damage also healthy tissue. There is also no discussion on the advantage of the green synthesis (especially for the antibiotic resistance) toward the usual processes. The article needs a revision.

Author Response

Hello,

Thank you for your review and comments about the article.

Our responses are below.

The Authors present neither physical-chemical characterization of the Silver nanoparticles nor those of supernatant. 

The aim of this study was to demonstrate the antibacterial activity of nanoparticles. Determination or confirmation of the physicochemical properties of silver nanoparticles and supernatant in this context was not an object for study. For this reason, to confirm the content of nanoparticles, we limited ourselves to the simplest method – spectroscopy.

There is no discussion of how these AgNPs must be employed in the new drug they quote.

We are not discussing how to use Ag nanoparticles in a new drug. The main task was to show the possibility of obtaining a substance with a pronounced antibacterial effect by green synthesis. To discuss the direct use as a finished drug, a number of complex and multi-stage studies must be carried out. In this article, we are talking about the prospect of using an antibacterial substance for drug development. The next step will be a thorough study of the possibility of using this substance as a medicine.

The toxicity of AGNPs they report can damage also healthy tissue.

Yes, this really can be. The article discusses bactericidal action. Studies on cell cultures or tissues of humans and animals have not been conducted. In the future, when developing the form of a potential drug, we will naturally conduct studies of cytotoxicity and genotoxicity.
We only studied the effect of nanoparticles on pathogenic bacterial cells. At this stage of research, there is no question of the direct development of drugs for use on living objects.

There is also no discussion on the advantage of the green synthesis (especially for antibiotic resistance) toward the usual processes.

Nanoparticles do not have an advantage, but are an alternative, as indicated in the article. The problem lies in the resistance of bacteria to antibiotics, which means that other sources of drugs with antibacterial action must be sought.

Reviewer 2 Report

The work presented by Kharchenko and colleagues deals with the proposed topic in an organic way. The manuscript is well written and performed experiments support conclusions in an appropriate way. I propose the acceptance of this work as it is.

Author Response

Hello,

Thank you for your review and good comments about the article.

Best wishes,

the authors of the article

Reviewer 3 Report

This manuscript entitled “Antibacterial activity of green synthesised silver nanoparticles on Saccharomyces cerevisiae” reveals supernatant-synthesised nanoparticles have higher antibacterial activity than nanoparticles synthesized using yeastlysate.  This study is valuable for drug application. However, there are still several mistakes in this manuscript.

Please add the title on X and Y axis in figure 1 and Figure 2.

This study objective is comparing antibacterial activity between supernatant-synthesised and yeastlysate. In Fig 3, Fig 4, Fig 5, Fig 6, just demonstrated that antibacterial activity of supernatant-synthesised or yeastlysate at different Ag concentration. I suggest that author should compare the antibacterial activity between supernatant-synthesised and yeastlysate at each concentration. That may be best way to display different antibacterial of these two nanoparticles. These figures need to be revised.

Author Response

Hello,

Thank you for your review and good comments about the article.

Our responses are below.

Please add the title on X and Y axis in figure 1 and Figure 2.

We added the title on X and Y axis in figure 1 and Figure 2.

This study objective is comparing antibacterial activity between supernatant-synthesised and yeast lysate. In Fig 3, Fig 4, Fig 5, Fig 6, just demonstrated the antibacterial activity of supernatant-synthesised or yeast lysate at different Ag concentrations. I suggest that the author should compare the antibacterial activity between supernatant-synthesised and yeast lysate at each concentration. That may be the best way to display different antibacterial of these two nanoparticles. These figures need to be revised.

Thanks for the suggestion to compare the antibacterial activity between the synthesized supernatant and the yeast lysate at each concentration. I think it is a good idea. But for now, the aim of the study is to study the antibacterial effect of nanoparticles obtained in different ways – thanks to supernatant and yeast lysate. We need to understand how effective this or that concentration of the initial salt of the initial cerium nitrate added to the synthesizing agent (supernatant or yeast lysate) is. For this reason that, for the most informative graphical representation, a comparison of the concentrations of the lysate and supernatant separately for the entire spectrum of bacterial strains was chosen. I agree that in Figures 3, 4, 5, 6 one could take as a basis for comparing the difference in antibacterial activity between the supernatant and lysate samples, but the graphical representation is not very informative and differs little from what is already there. Moreover, in my opinion, the most informative difference between the antibacterial action of the yeast lysate and the supernatant is the determination of the MIC, which is just presented in the article.

On the other hand, we could compare these indicators and broaden the horizons of our article, but the main part of the research conducted was carried out on the basis of Kyiv University. Due to the military situation in Ukraine, we cannot continue research at the moment. Also, we cannot send samples for research to our colleagues from Lithuania.

Best wishes,

the authors of the article

Round 2

Reviewer 1 Report

The article deals witha not very original topic. It was already revised by the authors and now it seems appropriate. So we propose to accept that.