Sustainable Microalgae and Cyanobacteria Biotechnology

Round 1

Reviewer 1 Report

Suggestions:

1. Please add definition of  'microalgae' to the introduction 

2. I believe it would be good to include a few facts on microalgae use in biotechnology in the historical perspective to the introduction

3. Some discussion on what prevents  microalgae applications in biotechnology  to be widespread till this moment 

4. The sustainability aspect of microalgae potential could be expanded 5.  What is the reason for this manuscript to discuss pigments and Superoxide dismutases in multiple details like their absorbance wavelengths?  6. The manuscript presents actual cases of successful application of microalgae to waste management and biofuels but lacks examples for other the fields mentioned like phycoremediation, additives for animal feeding, health care, and cosmetics.   7. missing references and style issues: a) The systematic names of the microalgae sometimes written in italic, other times in a regular font, yet should be consistent.  b) Please provide references supporting fact in Lines 46-47 - "microalgae and cyanobacteria. These organisms grew faster than terrestrial plants" as well as in lines 74-83  c) Line 103 has information that repeats itself from line 91 and I do not see a reason for such repetition d) Please expand the fact presented in the following sentence: Lines 162-163: "The natural isomers of microalgae carotenoids were found to be far superior to the synthetic all-trans form" e) Line 308 "Anti-immflamatory" should be changed to "anti-inflammatory" f) Lines 470-492 has formulas like ??/? =?? − ?0/?0 − ?? that are missing info on what their variables like S and Y are. Also, it's not clear to me what is the purpose to present these formulas here g) Lines 436 and 516 show the exact same equation, maybe you could just refer to it? h) Line 550 "The use of microalgae as nutritional additives for animal feed and human consumption has been used for many years"  This sentence should be re-written.  i) Line 723 HYDA genes are introduced without an explanation of what they stand for.  j) Please edit Lines 738-739 "Understanding the  regulation of the HYDA gene in order to facilitate biohydrogen production The industrial application of algal H2 production is complicated by oxygen sensitivity", I think some words are missing here      

Author Response

Please fine the document attached with the aswers to your suggestions 

Author Response File: Author Response.docx

Reviewer 2 Report

The manuscript reviews the potential of microalgae and cyanobacteria for production of high-value bioproducts and biofuel, as well as it’s biotechnological application for bioremediation. Overall, this is an important research that demonstrates the biotechnology potential of microalgae and cyanobacteria. A number of shortcomings that exist including some of major nature, which need to be addressed.  Should all comments be adequately addressed, publication in MDPI would be recommended. The English used in the manuscript is sub-standard and the grammar is not acceptable for publication in the present format, only two sections were looked at closely.

Microalgae derived high-value bioproducts is not new and the authors did not mention poly unsaturated fatty acids such as DHA and EPA, and company such as DSM has decades of experiences.

The comparison undertaken in the study would be particularly more relevant if conducted for microalgae species achieving commercial success with both higher biomass and high-value bioproducts.

The authors need to further clarify how sustainable development of microalgal biotechnology. For example the cost of bioreactors and downstream processes such as dewatering, drying, extraction methods will need to clarify for their energy uses and capital costs due to the fact that the cell concentration is often very low 0.3 g/L as illustrated in Table 4.

L 74 The authors need to rewrite section 2 Applications of microalgae biotechnology as it does not make sense. I personally disagree that the duration of application of certain product could be defined by time. 

L 75 Please define the applicability over time, with short, medium, and long term applications and developments. Short as in 1-2 years or months? 

Table 1. Please further explain the term for the ‘period of Time’ for the development for different application sector.

Line 153 Formatting error: ‘I’ should be (i)

Line 401 open raceway pond should be mentioned, as it has been the method of choice for microalgae

L 434 There appears to be excessive formulas for the manuscript.  The authors should consider which formulas are really essential, and cut some out.

L 643 ‘Tool’ not toll 

L763 there is no Figure 4

Why is it commercial production of microalgae is still not economical viable?

Perhaps the author can evaluate the viability of microalgal biorefinery with multiple product technology to enhance business development by producing high-value low-volume bioproducts coupled to biofuel production.

 

Author Response

Please find your answers in the attached document

Author Response File: Author Response.docx

Reviewer 3 Report

I have evaluated the manuscript (applsci-1759252) and  I found this article interesting for the readers and follow the scope of the journal Applied sciences. I don’t have any major comments as this review article is well organized, however, the author needs to elaborate the discussion of results with collected data, and the conclusion should be included with expert comments and a path forward. There are technical errors, and grammatical errors, I hope the editor will take care of them.

I would recommend the article could be published in Applied sciences. after minor corrections. 

Author Response

Please find your answer in the attached document

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Text still requires extensive editing. for example

  lines 62 and 66 are missing references for the presented facts line 120 - second "microalgae" should be "macroalgae" references list is not in a uniform format, and should be consistent. For example, lines 756, 741, 759, 763 and more has a different reference format, year is not in bold Line 271 has only one dot and nothing else Line 288 has a term "blue-green algae" that had been replaced many years ago to cyanobacteria. Also, the new, cyanobacteria, term is used a lot in the manuscript and their connection is not explained   *The manuscript is about microalgae and authors describe microalgae as eukaryotic species but there is a great length of facts on prokaryotic cyanobacteria in it. I suggest the title should be adjusted to include cyanobacteria.   

Author Response

Thank you for your revision

Author Response File: Author Response.docx

Reviewer 2 Report

Overall the authors responded to the queries and comments. 

However some minor editing is required before publication. Table1 'Bioprospecting' not 'Bioprospection',

Second column misspell 'health' 

Line 401 delete the repeated full stop

Line 472 check formulas order. Missing formulas no. 5 -6 and repeated no. 7.

Author Response

Thank you for your revision

Author Response File: Author Response.docx