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Microalgae species comparison
The main microalgae differ by group (green alga or cyanobacterium), habitat (fresh, alkaline or marine water), size and the high-value compound they accumulate. This table summarises the 9 species documented by ALGACEL, all with cited scientific data.
| Species | Group | Habitat | Size | Key compound/product | Main application |
|---|---|---|---|---|---|
| ChlorellaChlorella spp. | Eukaryotic green alga (Chlorophyta) | Freshwater | 2–10 µm | Food supplement and animal feed | Food supplement and animal feed |
| SpirulinaArthrospira platensis / A. maxima | Cyanobacterium (prokaryote) — grouped with microalgae | Alkaline freshwater | Tricomas filamentosos en espiral | Phycocyanin (blue) | Human food supplement (protein, phycocyanin) |
| ScenedesmusScenedesmus / Desmodesmus spp. | Eukaryotic green alga (Chlorophyta) | Freshwater | Cenobios de 4–8 células | Biomass and biofuel production | Biomass and biofuel production |
| HaematococcusHaematococcus pluvialis | Eukaryotic green alga (Chlorophyta) | Freshwater | 20–50 µm (quiste) | Astaxanthin | Astaxanthin for nutraceuticals |
| ChlamydomonasChlamydomonas reinhardtii | Eukaryotic green alga (Chlorophyta) | Freshwater / soil | ~10 µm | Research (photosynthesis, genetics, motility) | Research (photosynthesis, genetics, motility) |
| DunaliellaDunaliella salina | Eukaryotic green alga (Chlorophyta) | Hypersaline water | 7–25 µm | Beta-carotene | Beta-carotene for nutraceuticals and food |
| NannochloropsisNannochloropsis spp. | Eustigmatophyte (eukaryotic alga) | Marine / brackish water | 2–5 µm | EPA (omega-3) | Aquaculture (live feed and enrichment) |
| AnabaenaAnabaena / Dolichospermum spp. | Cyanobacterium (prokaryote) — grouped with microalgae | Freshwater | Filamentos (tricomas) de células | Nitrogen biofertilization (rice, Azolla–Anabaena) | Nitrogen biofertilization (rice, Azolla–Anabaena) |
| BotryococcusBotryococcus braunii | Eukaryotic green alga (Chlorophyta) | Freshwater | Colonias de células en matriz | Hydrocarbons | Biofuels (hydrocarbons) |
| EuglenaEuglena gracilis | Euglenoid (flagellate protist) — grouped with microalgae | Freshwater | 15–50 µm | Paramylon (β-1,3-glucan) | Food supplement (protein, vitamins, paramylon) |
| TetraselmisTetraselmis suecica | Eukaryotic green alga (Chlorophyta) | Marine / brackish water | 10–14 µm | Live feed in aquaculture (larvae, molluscs) | Live feed in aquaculture (larvae, molluscs) |
| PorphyridiumPorphyridium cruentum | Unicellular red alga (Rhodophyta) | Marine / moist soil | 5–10 µm | Phycoerythrin (red) | Phycoerythrin (colorant and fluorescent marker in diagnostics) |
| PhaeodactylumPhaeodactylum tricornutum | Diatom (Bacillariophyta) | Marine water | 10–35 µm (pleomórfica) | EPA (omega-3) and fucoxanthin | EPA (omega-3) for nutraceuticals and aquaculture |
Data from cited scientific literature (see sources on each species page). Ranges vary by strain and cultivation conditions.
How to choose the right microalga?
The choice depends on the target compound and end use: protein and phycocyanin point to Spirulina; astaxanthin to Haematococcus; beta-carotene to Dunaliella; omega-3 (EPA) to Nannochloropsis; and versatile biomass or water treatment to Chlorella and Scenedesmus. For agriculture and soil regeneration, freshwater species avoid adding salinity.
ALGACEL produces freshwater microalgae and supplies their biomass and ingredients to companies (B2B); specific specifications are defined per application.
Head-to-head comparisons
Frequently asked questions
Among the most cultivated, Spirulina (Arthrospira) stands out with a protein content of ≈60–70% of dry weight per FAO and the literature; Chlorella is around ≈45–60%.
Haematococcus pluvialis is the richest natural source of astaxanthin, which can reach around 5% of its dry weight (80–99% of its carotenoids).
Freshwater ones (such as Chlorella or Spirulina, which grows in alkaline waters) do not add marine salts or chlorides to the medium, which matters for agricultural and soil-regeneration uses. Nannochloropsis, by contrast, is marine/brackish.
Nannochloropsis stands out for its high EPA content (eicosapentaenoic acid, an omega-3), widely used in aquaculture and nutraceuticals.
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