Cited by 2,082Algal biology and biofuel productionMicrobial Metabolic Engineering and BioproductionSeaweed-derived Bioactive Compounds

The DOI matches its Crossref record; 242 of the 247 references it cites were found in a registry or an index; 2 of the 160 sources its claims cite were checked for support.

The promising future of microalgae: current status, challenges, and optimization of a sustainable and renewable industry for biofuels, feed, and other products

Open access
Khan, Muhammad Imran, Shin, Jin Hyuk, Kim, Jong Deog·2018·Microbial Cell Factories

Abstract

Microalgae have recently attracted considerable interest worldwide, due to their extensive application potential in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae are renewable, sustainable, and economical sources of biofuels, bioactive medicinal products, and food ingredients. Several microalgae species have been investigated for their potential as value-added products with remarkable pharmacological and biological qualities. As biofuels, they are a perfect substitute to liquid fossil fuels with respect to cost, renewability, and environmental concerns. Microalgae have a significant ability to convert atmospheric CO 2 to useful products such as carbohydrates, lipids, and other bioactive metabolites. Although microalgae are feasible sources for bioenergy and biopharmaceuticals in general, some limitations and challenges remain, which must be overcome to upgrade the technology from pilot-phase to industrial level. The most challenging and crucial issues are enhancing microalgae growth rate and product synthesis, dewatering algae culture for biomass production, pretreating biomass, and optimizing the fermentation process in case of algal bioethanol production. The present review describes the advantages of microalgae for the production of biofuels and various bioactive compounds and discusses culturing parameters.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

This review argues that microalgae are promising renewable feedstocks for biofuels, feed, and bioactive products, but commercialization requires overcoming growth, harvesting, pretreatment, and fermentation bottlenecks. It surveys cultivation parameters, strain improvement, and product classes while noting costs and technical limitations.

Key findings

  • Microalgae can fix 1.83 kg of CO2 per kg of algal biomass, and CO2 constitutes 50% of dry weight of algal biomass; many species accumulate 50–70% lipids, with *B. braunii* reaching up to 80%.
  • Reported algal oil productivity is 58,700 L/ha, which can yield 121,104 L/ha biodiesel; bioethanol production from microalgae is limited by low carbohydrate content, pretreatment, and fermentation efficiency.
  • Techno-economic estimates cited include biodiesel below $5/gallon gasoline equivalent and bioethanol at $2.95/gal as economically viable, while some studies suggest $1/L as feasible; commercial algal bioethanol output is cited at 1 billion gallons/year at 85 cents/L.
  • Microalgae produce valuable bioproducts including carotenoids, sterols, proteins, polyunsaturated fatty acids, vitamins, and toxic metabolites with antioxidant, anticancer, anti-obesity, and antimicrobial activities.

Methods

  • Design: narrative review; no primary experiments or systematic literature-search strategy are described.
  • Data/sample: synthesizes published literature and examples across microalgal species, cultivation systems, pretreatment and fermentation, and bioproducts; no original dataset is reported.
  • Main analysis: qualitative synthesis of advantages, challenges, and optimization parameters including light, temperature, nutrients, mixing, pH/salinity, mixotrophic cultivation, genetic modification, biomass pretreatment, and fermentation.

Limitations

  • The paper states that major challenges remain: enhancing microalgae growth rate and product synthesis, dewatering algae culture for biomass production, pretreating biomass, and optimizing fermentation for algal bioethanol.
  • It states that algal biofuels are not yet economically feasible, with high operational, maintenance, harvesting, and conversion costs, and that at least 10 more years of research and development are needed for economic viability.
  • Evident from the text: as a narrative review, it does not report systematic inclusion criteria, search methods, or quantitative synthesis, and many yield and cost figures rely on cited secondary sources rather than primary validation.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1186/s12934-018-0879-x

Cites

242 of 242 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Figures

Fig. 1 Microalgae convert atmospheric CO2 to carbohydrates, lipids, and other valuable bioproducts by using light. Microalgae biomass is a rich source for biofuels and bioactive compounds
Fig. 1 Microalgae convert atmospheric CO2 to carbohydrates, lipids, and other valuable bioproducts by using light. Microalgae biomass is a rich source for biofuels and bioactive compoundsCC BY · PubMed Central
Fig. 2 Different species of carbohydrate-rich microalgae that compose feasible feedstock for bioethanol production
Fig. 2 Different species of carbohydrate-rich microalgae that compose feasible feedstock for bioethanol productionCC BY · PubMed Central
Fig. 3 Pretreatment of microalgae biomass for biofuels production. Different types of biofuels can be produced depending on the raw materials used (carbohydrates and lipids) and the pretreatment prior to fermentation
Fig. 3 Pretreatment of microalgae biomass for biofuels production. Different types of biofuels can be produced depending on the raw materials used (carbohydrates and lipids) and the pretreatment prior to fermentationCC BY · PubMed Central
Fig. 4 Some value-added compounds produced by microalgae. a Astaxanthin, a strong antioxidant produced by the microalga Haematococcus pluvialis. b β-Sitosterol, produced by various genera of micro algae. Different species of Glaucocystophyte produce β-sitosterol. c Microcolin-A, an immunosuppressive agent produced by the microalga Lyngbya majuscule. d Docosahexaenoic acid DHA produced by the engineered strain of diatom Phaeodactylum tricornutum. e Structure of vitamin E (tocopherols), the microalga Haslea ostrearia naturaly produce vitamin E. f Chemical structure of okadaic acid, an anti-fungal agent produced by some species of dinoflagellates. g Chemical structure of microcystin-LR, produced by the blooming Microcystis aeruginosa
Fig. 4 Some value-added compounds produced by microalgae. a Astaxanthin, a strong antioxidant produced by the microalga Haematococcus pluvialis. b β-Sitosterol, produced by various genera of micro algae. Different species of Glaucocystophyte produce β-sitosterol. c Microcolin-A, an immunosuppressive agent produced by the microalga Lyngbya majuscule. d Docosahexaenoic acid DHA produced by the engineered strain of diatom Phaeodactylum tricornutum. e Structure of vitamin E (tocopherols), the microalga Haslea ostrearia naturaly produce vitamin E. f Chemical structure of okadaic acid, an anti-fungal agent produced by some species of dinoflagellates. g Chemical structure of microcystin-LR, produced by the blooming Microcystis aeruginosaCC BY · PubMed Central

Verification

Claims the paper makes

108 Not checked yet · 23 No basis given · 15 Own interpretation · 1 Supported so far · 1 Couldn’t confirm · accuracy not yet measured

Verify all 158 references — free account

Show all 67 claims

  • It may state two separate claims as one. 52
  • Probably not a substantial claim. 51
81 of 81
  • The paper relies on this without support.

    On a large scale, algal biomass pretreatment is a bottleneck and potentially costly step in biofuel production.

    “On a large scale, biomass pretreatment is a bottleneck and potentially costly step in biofuels production.”
  • The paper relies on this without support.

    There is still no optimal, highly productive method for pretreatment of algal biomass.

    “Many different methods have been described for the pretreatment of algal biomass, but there is still no optimal, highly productive method.”
  • The paper relies on this without support.

    Microalgae production has not been fully commercialized because of several obstacles and challenges.

    “Although microalgae have many potential applications for biofuel and other useful products, 48 their production has not been fully commercialized because of several obstacles and challenges.”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

4 of 4

Citations

Cites

1 retracted

Show all 247 references

Research works printed but not linked: 20

  1. Medipally SR, Fatimah M, Banerjee YS, Shariff M. Microalgae as sustainable renewable energy feedstock for biofuel production. Biomed Res Int. 2015. https://doi.org/10.1155/2015/519513 . · DOI · Paper page
  2. Gendy Tahani S, Seham A. El-temtamy commercialization potential aspects of microalgae for biofuel production: an overview. Egyptian J Pet. 2013;22:43–51. · DOI · Paper page
  3. Duvall MN, Fraker RN. Algae-based biofuels attract incentives and investments. Washington, D.C.: Beveridge & Diamond, P.C.; 2009.
  4. Ozkurt I. Qualifying of safflower and algae for energy. Energy Educ Sci Tech. 2009;23:145–51.
  5. Craggs RJ. Wastewater treatment by algal turf scrubbing. In: 7th international conference on wetland systems for water pollution control, Lake Buena Vista: I Wa Publishing; 2000.
  6. Mata TM, Martins AA, Caetano NS. Microalgae for biodiesel production and other applications: a review. Renew Sust Energy Rev. 2010;14:217–32. · DOI · Paper page
  7. Alabi AO, Tampier M, Bibeau E. Microalgae technologies and processes for biofuels bioenergy production in british columbia. Current technology, suitability and barriers to implementation. Final report submitted to The British Columbia innovation council. Cambridge: Seed Science Press; 2009.
  8. Carvalho AP. Light requirements in microalgal photobioreactors. Berlin: Springer; 2010.
  9. Dragone G, Fernandes B, Vicente A, Teixeira JA. Third generation biofuels from microalgae, current research, technology and education. Appl Microbiol Biotechnol. 2010;2:1355–66.
  10. Jensen GS, Ginsberg DI, Drapeau MS. Bluegreen algae as an immuno-enhancer and biomodulator. J Am Nutraceutical Assoc. 2001;3:24–30.
  11. Cornet JF. Le technoscopeles photobioreacteurs. Biofutur. 1998;176:1–10.
  12. Pulz O, Gross W. Valuable products from biotechnology of microalgae. Appl Microbiol Biotechnol. 2004;65:635–48. · DOI · Paper page
  13. Sathasivam R, Juntawong N. Modified medium for enhanced growth of Dunaliella strains. Int J Curr Sci. 2013;5:67–73.
  14. Raposo MFJ, Mendes-Pinto MM, Morais R. Carotenoids, foodstuff and human health. In: Morais R, editor. Functional foods an introductory course. Porto: Universidade Católica Portuguesa—Escola Superior de Biotecnologia; 2001.
  15. Cuvelier M-E. Antioxidants. In: Morais R, editor. Functional foods: an introductory course. Portugal: Escola Superior de Biotecnologia/UCP; 2001. p. 97–108.
  16. . Zhang Y. Sterols in Microalgae: Euglena gracilis and Selenastrum sp. master’s thesis University of Helsinki, Faculty of Agriculture and Forestry, Department of Food and Environmental Sciences.
  17. Gouveia L, Batista AP, Sousa I, Raymundo A, Bandarra N. Microalgae in novel food products. In: Konstantinos N, Papadopoulos PP, editors. food chemistry research development. New York: Nova Science Publishers; 2008. p. 75–112.
  18. . Guedes ACA. Production, extraction and characterization of selected metabolites from microalgae and cyanobacteria. Ph.D. Thesis Porto,: Escola Superior de Biotecnologia, Universidade Católica Portuguesa; 2010.
  19. Sarrobert B, Dermoun D. Extraction et valorisation de molecules à haute valeur ajoutée chez la microalgae Porphyridium cruentum. Premier Colloque Scientifique Français sur la Biotechnologie des Microalgues et des Cyanobacteries Appliquée au Thermalisme, vol. 24. France: Centre d’Études Nucléaires de Cadarache; 2008. p. 109–14.
  20. Nair S, Bhimba BV. Bioactive potency of cyanobacteria Oscillatoria spp. Int J Pharm Pharm Sci. 2013;5:611–2.

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Metadata

Authors
Khan, M. I., Shin, J. H., & Kim, J. D.
Affiliations
Chonnam National University (KR)
Corresponding author
Kim, Jong Deog
Venue
Microbial Cell Factories
Published
2018-03-05
Volume
17
Issue
1
Pages
36-36
ISSN
1475-2859 (ISSN-L)
OpenAlex
W2802803660
Cited by
2,082
References
247
Citations by year
2026: 162 · 2025: 274 · 2024: 301 · 2023: 317 · 2022: 352 · 2021: 321 · 2020: 223 · 2019: 121 · 2018: 9
FWCI
9.01
Type
journal article
Language
en
Open access
Licence
cc-by
Locations
  • Microbial Cell Factories (publishedVersion, cc-by)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Topics
  • Physical Sciences › Energy › Renewable Energy, Sustainability and the Environment › Algal biology and biofuel production
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Microbial Metabolic Engineering and Bioproduction
  • Life Sciences › Agricultural and Biological Sciences › Aquatic Science › Seaweed-derived Bioactive Compounds
Keywords
microalgae, algal biofuels, bioethanol production, CO2 fixation, biomass pretreatment, fermentation optimization, bioactive compounds, microalgae feed, biopharmaceuticals, nutraceuticals, industrial scale-up
MeSH terms
Biopharmaceutics, Fermentation, Industrial Microbiology, Biomass, Biofuels, Microalgae

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