Applied Phycology – Role of algae in the environment, agriculture, biotechnology and industry

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Phycology is the study of algae. It is also known as algology. It is a branch of biology and deals with different algal forms.

In phycology, the structure, classification, physiology, ecology and distribution of algae are studied. It includes both small algae and large seaweeds. Cyanobacteria, microalgae, macroalgae and seaweeds are included in this study.

Algae are divided into different groups. Some important groups are Chlorophyta, Rhodophyta, Phaeophyta and cyanobacteria. This classification is made on the basis of pigments, cell structure and reproduction.

The physiological study of algae includes photosynthesis, food storage, growth and nutrient uptake. Algae prepare food by photosynthesis. So they act as important producer in water bodies.

The ecological study of algae is also included in phycology. Algae are found in freshwater, marine water and moist land places. They form food for many aquatic animals and also produce oxygen.

Algae have many economic uses. They are used as food, medicine, fertilizer and in industries. They are also studied for biofuel, bioremediation and bioactive compounds.

Algae are used as bioindicators also. Changes in algal growth shows change in water quality. It also indicates nutrient level and condition of aquatic ecosystem.

Role of algae in the environment

  1. Oxygen production– Algae produce oxygen by photosynthesis. Oxygen is released in water and air. Nearly 50% oxygen of earth is produced by algae. It is useful for microbes, fishes and other living forms.
  2. Food web– Algae are primary producers. They prepare food by sunlight. Small animals eat algae. Then larger animals eat those small animals. So food chain is maintained.
  3. Biodiversity– Algae support many organisms in water body. They give food and base for aquatic life. Due to this biodiversity of ecosystem is maintained.
  4. Carbon fixation– Algae absorb carbon dioxide from air and water. Carbon is fixed in their body during growth. So algae act as carbon sink.
  5. Climate balance– By fixing carbon dioxide, algae reduce some greenhouse gas. So they have role in climate balance. It helps against climate change in natural way.
  6. Air purification– Some algae take nitrogen oxides (NOx) from atmosphere. This reduces air pollution in some extent. So algae also help in air cleaning.
  7. Water purification– Algae absorb extra nitrogen and phosphorus from water. Nutrient pollution become less. Water body remain more balanced.
  8. Pollutant removal– Some algae break organic pollutants. Some algae bind heavy metals also. Thus polluted water become cleaner by algal action.
  9. Biogeochemical cycle– Algae take part in carbon cycle, nitrogen cycle and phosphorus cycle. Nutrients move from one part to another part. So ecosystem function continues.
  10. Algal bloom– Algae may be harmful when they grow very fast. In nutrient rich water, algal bloom is formed. After death of bloom, decomposers use oxygen from water. Oxygen become low and fishes may die.

Role of algae in the agriculture

  1. Biofertilizer– Algae are used as biofertilizer. They give nitrogen, phosphorus, potassium, calcium and magnesium to soil. Soil organic matter increase. Use of chemical fertilizer become less. Cyanobacteria fix atmospheric nitrogen by nitrogenase enzyme.
  2. Plant growth– Algal extract helps in plant growth. It helps seed germination. It helps seedling development. Crop yield also increase. Auxins, cytokinins, gibberellins and abscisic acid are present.
  3. Stress resistance– Algal polysaccharides and extract help crop during stress. They help in drought condition. They help in extreme temperature and high salinity also. So plant survive better.
  4. Pest control– Some algae produce secondary metabolites. These substances work against fungi, bacteria, virus, insects and nematodes. They also stimulate defence system of crop plant.
  5. Nutrient uptake– Algae act on root region or rhizosphere. They help to make minerals available in soil. So plant absorb nutrients easily.
  6. Animal feed– Some algae are used in cattle feed. Red seaweed Asparagopsis taxiformis reduce methane formation in rumen. It suppress methanogenic bacteria. Feed efficiency also improve.
  7. Runoff treatment– Microalgae are used in agricultural wastewater treatment. They absorb excess fertilizer from runoff water. They also degrade pesticides and herbicides before water pollution.

Role of algae in the biotechnology

  1. Biofactories– Microalgae are used as small biofactories. By CRISPR/Cas9 and genetic engineering method, they produce recombinant enzymes, therapeutic proteins, human antibodies and edible vaccines.
  2. Bioplastics and biopolymers– Algae are source of biopolymers. They produce polyhydroxyalkanoates (PHAs), alginate and agar. These are biodegradable materials and used instead of petrochemical plastics in packaging and industrial materials.
  3. Medical use– Algal compounds are used in medical biotechnology. Carrageenan, fucoidan and alginate are used in drug delivery, wound dressing and tissue engineering scaffold. Some marine compounds show antiviral, antimicrobial and anticancer property.
  4. Nutraceuticals– Algae are grown for useful health compounds. They produce omega-3 fatty acids like EPA and DHA, vitamins and antioxidant pigments. Astaxanthin and β-carotene are important pigments obtained from algae.
  5. Cosmetics– Algal extracts are used in cosmetic products. They are used for skin hydration, anti-aging, natural UV protection and hair care. These compounds are obtained from bioactive molecules of algae.
  6. Energy storage– Algal biopolymers are studied in material science. They are used for making green battery components. They can work as solid polymer electrolyte, binder and separator membrane.
  7. Biofuel– Algae are used as third generation feedstock. Algal biomass gives biodiesel, bioethanol, biohydrogen and biomethane. So algae are useful renewable source instead of fossil fuel.

Role of algae in the industry

  1. Food and beverage industry– Algae are used as functional food and dietary supplement. They are source of protein and omega-3 fatty acids. Agar, alginate and carrageenan are used as thickener, stabilizer and gelling agent. Astaxanthin and phycocyanin are used as natural food colour. Algal coating is also used in edible packaging and increase shelf life of fresh food.
  2. Pharmaceutical and biomedical industry– Algal biopolymers are useful in medicine industry. They are used in drug delivery system, wound dressing, tissue engineering scaffold and 3D bioprinting material. Some algal compounds show antiviral, antimicrobial, anticancer and anti-inflammatory property. Microalgae also work as biofactories and produce therapeutic proteins, human antibodies and edible vaccines.
  3. Cosmetics and personal care industry– Algal extracts are used in skin care and hair care products. They have antioxidant, hydrating and skin regenerating property. Fucoxanthin and phloroglucinol give protection from UVA and UVB rays. So they are used in sunscreen and anti-aging products.
  4. Energy and biofuel industry– Algal biomass is used as third generation fuel source. It gives biodiesel, bioethanol, biomethane and biohydrogen. These fuels are renewable and less harmful than fossil fuels.
  5. Plastics and material industry– Algae are source of biopolymers like polyhydroxyalkanoates (PHAs). These are used for biodegradable plastics and compostable packaging. Algal biopolymers are also used in green battery study as solid polymer electrolyte and separator membrane.
  6. Chemical manufacturing industry– Microalgae give useful chemicals like lactic acid, succinic acid and 5-hydroxymethylfurfural. These are renewable chemicals and can replace fossil oil based chemicals. Algal pigments are also used for natural dyes and paints.
  7. Wastewater and environmental industry– Algae are used in phycoremediation. They treat sewage, agricultural runoff and industrial wastewater such as dairy, paper and tannery effluents. They remove heavy metals, excess nutrients and organic pollutants. They also absorb carbon dioxide from industrial flue gases.
  8. Animal feed and aquaculture industry– Algal biomass is used as feed supplement. It is used for poultry, pigs and fishes because it has amino acids and lipids. Red seaweed Asparagopsis taxiformis is used in cattle feed and it reduces methane production from rumen.

References

  1. ResearchGate. (n.d.). (PDF) Phycoremediation of industrial wastewater: review of algae consortia.
  2. A review of microalgae- and cyanobacteria-based biodegradation of organic pollutants. (n.d.).
  3. Mhamunkar, N. (2025). Algae for a cleaner future: An in-depth look at phycoremediation. Agro Morph.
  4. Advanced algal phycology and biotechnology: Structural biopolymers, agro-biotechnology, enteric methane mitigation, phycoremediation engineering, and precision CRISPR-Cas9 genomics. (n.d.).
  5. Morris, H., Coombes, Z., El Dor, Z., Rodrigues, V. J., Silkina, A., Marchese, P., Murphy, M., Adams, J. M. M., Barry, F., Fuentes-Grünewald, C., Rachidi, W., & Gonzalez, D. (2026). Algae-derived bioactive compounds as platforms for translational biotechnology and health applications. BioTech, 15(2), 34.
  6. ResearchGate. (n.d.). Algae-derived hydrocolloids in foods: applications and health-related issues.
  7. Lomartire, S., & Gonçalves, A. M. M. (2023). Algal phycocolloids: Bioactivities and pharmaceutical applications. Marine Drugs, 21(7), 384.
  8. Ansari, F. A., Hassan, H., Al-Ouweini, A. S. S., Chabukdhara, M., Shakya, A., Sheik, A. G., Alghamdi, S., Naser, I., Waqas, S., & Ahmad, I. (2026). An integrated algal biorefinery approach for wastewater treatment and biomass valorisation. Sustainability, 18(4), 2123.
  9. CRISPR-Cas technology turns Chlamydomonas reinhardtii into a flagship for algal biotechnology. (n.d.). PMC.
  10. CRISPR-Cas technology turns Chlamydomonas reinhardtii into a flagship for algal biotechnology. (n.d.). PubMed.
  11. Seralathan, M. S., Kirubha, C., Varanavasiappan, S., Suresh, R., Anandham, R., Raveendran, M., & Raghu, R. (2025). CRISPR/Cas genome editing in microalgae: Revolutionizing biotechnology through precision genetic engineering. Plant Science Today, 12(4).
  12. Cas9-mediated gene-editing frequency in microalgae is doubled by… (n.d.). PNAS Nexus.
  13. Comparative analysis of macroalgae supplementation on the rumen microbial community: Asparagopsis taxiformis inhibits major ruminal methanogenic, fibrolytic, and volatile fatty acid-producing microbes in vitro. (n.d.). PMC.
  14. Fabris, M., Abbriano, R. M., Pernice, M., Sutherland, D. L., Commault, A. S., Hall, C. C., Labeeuw, L., McCauley, J. I., Kuzhiuparambil, U., Ray, P., Kahlke, T., & Ralph, P. J. (2020). Emerging technologies in algal biotechnology: Toward the establishment of a sustainable, algae-based bioeconomy. Frontiers in Plant Science, 11, 279.
  15. Enhanced production of bioactive polyunsaturated fatty acids and pigments in Rhodosorus marinus: Optimization of thermal and photic stress conditions. (n.d.). PMC.
  16. Dele-Afolabi, T. T., Azmah Hanim, M. A., & Al-Qureshi, H. A. (2025). From petrochemical to photosynthetic: Algae-derived polymers for sustainable industrial applications. Journal of Research Updates in Polymer Science, 14, 120-134.
  17. Hassanien, A. H., Saadaoui, I. S., Schipper, K. S., Al-Marri, S. A., Dalgamouni, T. D., Aouida, M. A., Saeed, S. S., & Al-Jabri, H. M. (2023). Genetic engineering to enhance microalgal-based produced water treatment with emphasis on CRISPR/Cas9: A review. Frontiers in Bioengineering and Biotechnology, 10, 1104914.
  18. Highly valuable polyunsaturated fatty acids from microalgae: Strategies to improve their yields and their potential exploitation in aquaculture. (n.d.). PMC.
  19. Impakter. (2026, May 19). How seaweed can help curb methane emissions from cows.
  20. Industrial and biotechnological applications of algae: A review. (n.d.). Open Access Pub.
  21. Barry, S., Maier, G., Davy, J. S., Forero, L., & Warner, A. (2025). Investigating supplementation with Asparagopsis taxiformis in mineral to reduce enteric methane from grazing cattle. Methane, 4(4), 27.
  22. Micro- and macro-algae combination as a novel alternative ruminant feed with methane-mitigation potential. (n.d.). PMC.
  23. Minhas, A. K., Gaur, S., Sunny, S., Paladugu, C., Ravishankar, G. A., Pereira, L., & Ambati, R. R. (2026). Microalgae-based wastewater treatment processes for the bioremediation and valorization of biomass: A review. Phycology, 6(1), 18.
  24. ResearchGate. (n.d.). Microalgae-based biorefineries using and treating wastewater, follow the circular economy concept.
  25. Chen, W., Li, T., Du, S., Chen, H., & Wang, Q. (2023). Microalgal polyunsaturated fatty acids: Hotspots and production techniques. Frontiers in Bioengineering and Biotechnology, 11, 1146881.
  26. Vandana, R., & Rakesh, S. (2023). Phyco-remediation of sewage wastewater by microalgae. In B. K. Taşeli (Ed.), Sewage Management. IntechOpen.
  27. Schenk, P. M. (2021). Phycology: Algae for food, feed, fuel and the planet. Phycology, 1(1), 76-78.
  28. Potential applications of algae in biochemical and bioenergy sector… (n.d.).
  29. Provectus Algae. (n.d.). Product.
  30. Orejuela-Escobar, L., Gualle, A., Ochoa-Herrera, V., & Philippidis, G. P. (2021). Prospects of microalgae for biomaterial production and environmental applications at biorefineries. Sustainability, 13(6), 3063.
  31. Recent biotechnological applications of value-added bioactive compounds from microalgae and seaweeds. (n.d.). PMC.
  32. Red seaweed (Asparagopsis taxiformis) supplementation reduces… (n.d.).
  33. Red seaweed supplementation suppresses methanogenesis in the… (n.d.).
  34. Rumen microbial degradation of bromoform from red seaweed. (n.d.). eScholarship.org.
  35. Rumen microbial degradation of bromoform from red seaweed… (n.d.).
  36. Berthon, J.-Y., Michel, T., Wauquier, A., Joly, P., Gerbore, J., & Filaire, E. (2021). Seaweed and microalgae as major actors of blue biotechnology to achieve plant stimulation and pest and pathogen biocontrol – a review of the latest advances and future prospects. The Journal of Agricultural Science, 159(7-8).
  37. Smith Lab. (n.d.). Seaweed as a tool for methane reduction in livestock.
  38. Ahmad, I., Abdullah, N., Koji, I., & Yuzir, A. (2021). The contribution of microalgae in bio-refinery and resource recovery: A sustainable approach leading to circular bioeconomy. Chemical Engineering Transactions, 89, 391-396.
  39. Leong, Y. K., & Chang, J.-S. (2023). Waste stream valorization-based low-carbon bioeconomy utilizing algae as a biorefinery platform. Renewable and Sustainable Energy Reviews, 178(C).

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