Oxygen Uptake Rate as an Indicator of the Substrates Utilized by Candidatus Accumulibacter
, Yulia Berestovskaya 1, Evgeny Gruzdev 2, Andrey Mardanov 2 and Nikolai Pimenov 1Round 1
Reviewer 1 Report
I have included some of the recommendations and observations in the attached document.
Comments for author File: 
Comments.pdf
Author Response
Dear Reviewer,
thank you for being a very good observer!
We have made several changes in the text according to your recommendations. At the same time, we have left the units P-mol/S-mol and РО43--P/L the same as they are widely used (For example see Wang, L.; Liu, J.; Oehmen, A.; Le, C.; Geng, Y.; Zhou Y. Butyrate can support PAOs but not GAOs in tropical climates. Water Res. 2021, 193, 116884. https://doi.org/10.1016/j.watres.2021.116884).
Regarding your question about style of “Candidatus Accumulibacter” we can comment, that this style is convenient and is generally accepted in microbiological papers. Accordingly, Ca. is abbreviation from Candidatus.
The best quality drawings were sent with original materials at submission.
Reviewer 2 Report
The paper is of interest in the field of biotechnology research, and the results promise to bring added value to identify the spectrum of organic substrates used as energy sources by a Candidatus Accumulibacter.
1. Introduction
The introduction is very well documented and updates the approached issue.
Line 86. Please mention in text what FISH means.
2. Materials and Methods
Correct and comprehensive description of materials is presented.
Some supplementary information is needed, as follows:
-Line 152. Please mention in text what COD means.
-Line 181. Please mention in text what TSS and VSS mean.
-Line 184. Please mention the statistical program used for data processing.
3. Results are presented clear, and
4. Discussions are detailed and documented.
5.Conclusion
Conclusions are consistent with the goal of the presented research, but we recommend authors to mention the novelty brought by their research compared to the present level of knowledge in the field.
Author Response
Dear Reviewer,
thank you very much for taking the time to review this manuscript.
Please find the detailed responses below.
Comments 1: Line 86. Please mention in text what FISH means.
Response 1: Dear Reviewer, we replaced “FISH” with “fluorescence in situ hybridization”.
Comments 2: Line 152. Please mention in text what COD means.
Response 2: Dear Reviewer, we have added a deciphered abbreviation to the text:
«Chemical Oxygen Demand (COD)»
Comments 3: Line 181. Please mention in text what TSS and VSS mean.
Response 3: Dear Reviewer, we have added a deciphered abbreviation TSS and VSS to the text:
“Phosphate ion concentration, Total Suspended Solids (TSS), and Volatile Suspended Solids (VSS) were determined as described previously”
Comments 4: Please mention the statistical program used for data processing.
Response 4: : Dear Reviewer, we have made the following changes to the Statistical data processing section (underlined text):
Average values and standard deviation were calculated for each experimental point using statistical functions in Microsoft Excel software. The deviation was within the limits of experimental data scattering and did not exceed 5%. It is shown on the graphs as data scattering.
Comments 5 Conclusions are consistent with the goal of the presented research, but we recommend authors to mention the novelty brought by their research compared to the present level of knowledge in the field.
Response 5: Dear Reviewer, we have made changes in conclusion (underlined text):
«In the present work, the oxygen uptake rates of Ca. Accumulibacter-enriched culture were measured for 17 organic substrates in order to determine the spectrum of the sub-strates used by Ca. Accumulibacter. The highest OUR values were observed for tryptone, acetate, propionate, butyrate, succinate, pyruvate, aspartate, and glutamate. Dynamics of phosphate release/uptake upon respective shift from anaerobic to aerobic conditions was studied for these compounds in batch experiments. Based on stoichiometric data and the results of metagenomic analysis, it was concluded that all studied compounds could be used by Ca. Accumulibacter as substrates. In this work, for the first time, a correlation was discovered between OUR and the amount of phosphates consumed during the aerobic phase. OUR was proposed as a rapid indicator for search of the substrates used by Ca. Accumulibacter.
