Review Reports

Round 1

Reviewer 1 Report

This is an interesting paper that presents novel work on the phytoremediation of soils contaminated with heavy metals.  The authors tested the effectiveness of different soil characteristics and rhizobacteria on the growth of narra trees.  Their work will be of interest to the scientific community. 

 

Before this paper can be published the authors should address the following comments: 

 

Abstract needs to be rewritten to fix a number of mistakes:

1.  Line 23, I don’t think the word “proven” should be used.  I suggest changing “proven” to “understood”.  

2.  Line 23, change “before as a soil bioremediation agent” to “before it can be used as a soil bioremediation agent”.  

3.  Line 25, change micro-organisms to microorganisms

4.  Line 25, capitalize “Narra”

5.  Line 37, italicize “Pseudomonas synxantha”.

6.  Line 37, what does ACC stand for in ACC deminase?  The first time an abbreviation is used it should be spelled out in full, i.e, it should read “1-aminocyclopropane-1-carboxylate (ACC) deaminase”. 

7. Line 40, P. synxantha PbSM 2.1 should be replaced with either “P. synxantha  A1” or “PbSM 2.1”.

8.  Line 41, should the word “narra” be capitalized or in lower case?  In some instances the authors use “Narra” and in other instances the authors use lower case “narra”.  Authors should be consistent throughout paper.  

 

Material and Methods:

9.  Line 107, The soil was collected from Kentrong, but the authors don’t provide information on how the soil was stored (e.g., temperature, humidity, light/dark, etc.) before the soil was used in their experiments.  They should provide this information.  

10. Line 113, the authors describe three bacteria species used in their experiments and say where they were isolated from and that they demonstrated in-vitro plant growth properties.  They need to provide citations for references that describe these characteristics.  If references don’t exist, they need to provide data for these assertions.  

11.  Line 118, “Randomized Completely Design” doesn’t make sense.  Did the authors mean to write “Completely randomized design”?  

12.  Line 130, was the 1 kg of soil wet weight or dry weight?  

13.  Line 146, how was the pellet re-suspended in the sterile solution?  Was a vortex mixer used or mixing by hand or pipette or shaker table?

14.  Line 152, shouldn’t narra be capitalized?

15.  Line 154, approximately how often were plants watered?  Were they watered with dH2O or tap water?

16.  Line 161, “have” should be changed to “had”.

17.  Line 164, should read “…soil parameters used in this study have been previously described in Evict and Sulaeman {29]”.  

18.  Line 167, please provide weblink or reference for SPSS Version 25.  

 

Results:

19.  Line 217, I’m not familiar with the term “Aldd”.  Did the authors mean to write “Al” or aluminum?

20.  Please provide a reference for their statement that Al content could be toxic to plant.  Or data for how they determined that Al was toxic to plant at this concentration.  

21.  Line 223, this seems like it would be better suited for Discussion section rather than Results section: “Aside from hydrogen and aluminum ion toxicity in such acid soil, the toxicity of Mn and added Cu became constrain to plant and microorganism growth. Liming and compost application were needed to improve the fertility of this soil.”

22.  Table 2, Table 3 and Table 4, authors don’t explain what a, b, c, d, e, f, g are.  They should include this information in the Table.  I’m not sure what LF0,1, C0,4 and I0 mean.  They should explain this better in Table 2 legend.  

23.  Lines 263-290 seems like it should all be included in Discussion section and not Results.

24.  Line 278, authors should provide citations to Reference(s) where this information on phytoextraction was obtained.    

 

Discussion:

25.  Line 343, provide citation(s) for this statement.  

26.  Line 370, what do the asterisks mean?

27.  Lines 383-390, sometimes “Shoot Cu” was used and other times “shoot Cu” was used.  Please be consistent with capitalization.  

28.  Line 399, reference table that provides data showing Kentrong soil had hummus similar to soil organic matter.  

 

Conclusion:

29.  Line 447, this sentence doesn’t make sense to me, please re-write.  

Author Response

Thanks for the input from the reviewers. We have corrected the manuscript point by point in accordance with the suggestions from the reviewers.  

Reviewer 2 Report

the author highlight the importance of lime

should provide the mechanism involved for lime to plant growth promotion

why the author didn't check the heavy metal absorption (isotherm kinetics)?

why the author using artificial soil for this experiment? any specific method involved in this research?

did the author refer any other microbial consortium for metal removal process?

Author Response

1.Liming and compost application were needed to improve the fertility of this soil. In agricultural practice, liming is carried out for reducing soil acidity and Lime the recommended  were  used as positive controls to evaluate the ability of inoculations and composts to promote the growth and used as positive controls to evaluate the ability of inoculants.

2. The author didn't check the heavy metal absorption (isotherm kineticks), but we done uptake of Cu. Plant Cu uptake had a significant negative correlation with shoot Cu content (r = -0.441) (Table 4).

3.This research does not use artificial soil but uses soil from field. We soil was collected from Kentrong, Banten Province, Indonesia. 

4. Three rhizobacteria used in this experiment, i.e., CuNFbM 4.1, MGR 333, and PbSM 2.1 are HM resistant and isolated from the Cu mining site in Marinduque.

Reviewer 3 Report

The article can be accepted with modification in english language and improvement in discussion section.

Author Response

We have been improvement modification in english language and improvement in discussion section. The improvements directly poured in the paper.

Thanks you

Round 2

Reviewer 1 Report

This is important research and worthy of publication.  The manuscript is well written.  The authors have addressed all concerns in their revised manuscript.  Publish manuscript.