Recent Advances in Biosurfactant Production in Solid-State Fermentation
, Luis V. Rodríguez-Durán 1,*, María Alejandra Pichardo-Sánchez 1,2, Nubia R. Rodríguez-Durán 1, Nadia A. Rodríguez-Durán 1, Daniel Trujillo-Ramírez 1 and Rodolfo Torres-de los Santos 1Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe manuscript presents a comprehensive and timely review of recent advances in biosurfactant production through solid-state fermentation. The topic is relevant to the journal’s scope and provides valuable insights into sustainable bioprocessing. Overall, the manuscript is well organized and informative. To further strengthen its quality, a few minor improvements are suggested below.
- The review provides valuable insights into SSF-based biosurfactant production. Including a short comparative discussion on factors affecting yield differences among substrates or microbial strains would further enhance the scientific depth of the manuscript.
- The advantages of SSF are well summarized. However, briefly addressing its current challenges—such as substrate heterogeneity or scale-up issues—could provide a more balanced and comprehensive overview.
- The section on AI and modeling is interesting but rather brief. Expanding it with one or two recent examples of AI-based optimization could strengthen the technological relevance of the review.
In summary, the manuscript is of good quality and contributes to the field. Addressing the above points would further improve its clarity and overall impact.
Author Response
Comment 1: The review provides valuable insights into SSF-based biosurfactant production. Including a short comparative discussion on factors affecting yield differences among substrates or microbial strains would further enhance the scientific depth of the manuscript.
Response 1: New information on the effect of carbon sources and strain differences on biosurfactant production has been added to the end of sections 5.1 and 5.2.
Comment 2: The advantages of SSF are well summarized. However, briefly addressing its current challenges—such as substrate heterogeneity or scale-up issues—could provide a more balanced and comprehensive overview.
Response 2: A new section (7) was added at the end of the manuscript
Comment 3: The section on AI and modeling is interesting but rather brief. Expanding it with one or two recent examples of AI-based optimization could strengthen the technological relevance of the review.
Response 3: New information added at the end of section 6
New references were added
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsComments and Suggestions for Authors
The study focuses on evaluating the production of biosurfactants using solid-state substrates, which—unlike the more commonly used liquid media—remain a less popular cultivation method. The authors also provide a classification of biosurfactants based on their chemical structure. A key aspect of the paper is the discussion of strategies that may enhance the yield of these valuable compounds in solid-state fermentation. The article serves as a valuable source of information for researchers interested in alternative methods of biosurfactant production. However, it should be noted that, although the authors consistently emphasize the potential use of waste products exclusively in solid-state cultivation, numerous literature reports indicate that such materials can also be successfully applied in submerged fermentation. In my opinion, the study requires some editorial revision.
Some minor suggestions:
L27: what is mean : bed temperaturę?
L61: The table lacks a descriptive title.
L63-64: This sentence is unclear and needs to be revised.
Comments for author File: Comments.pdf
Author Response
Comment 1: The study focuses on evaluating the production of biosurfactants using solid-state substrates, which—unlike the more commonly used liquid media—remain a less popular cultivation method. The authors also provide a classification of biosurfactants based on their chemical structure. A key aspect of the paper is the discussion of strategies that may enhance the yield of these valuable compounds in solid-state fermentation. The article serves as a valuable source of information for researchers interested in alternative methods of biosurfactant production. However, it should be noted that, although the authors consistently emphasize the potential use of waste products exclusively in solid-state cultivation, numerous literature reports indicate that such materials can also be successfully applied in submerged fermentation. In my opinion, the study requires some editorial revision.
Response:
Solid byproducts have been used as a carbon source for biosurfactant production in submerged fermentation. However, to utilize the nutrients in these byproducts, they must undergo processes such as thermal pretreatment, chemical or enzymatic hydrolysis, and detoxification. These steps increase the energy requirements and overall cost of the process. SSF allows the use of solid lignocellulosic by-products with minimal pretreatment. These by-products can be used as inert support or as both a support and substrate. This information was added to section 3 (L78 to 84).
Some minor suggestions:
Comment 1: L27: what is mean: bed temperaturę?
Response 1: Bed temperature is a term commonly used in SSF to refer to the temperature of the solid substrate. To avoid confusion, the word "bed" has been removed.
Comment 2: L61: The table lacks a descriptive title.
Response 2: A descriptive title was added to Table 1
Comment 3: L63-64: This sentence is unclear and needs to be revised.
Response 3: The sentence was rephrased
"Please see the attachment."
Author Response File: Author Response.pdf
