Microalgae are microscopic plants that play a pivotal role in global biological productivity. They are among the most efficient photosynthetic organisms on earth and contribute significantly to the global carbon cycle. Of the thousands of species of microalgae, Chlorella is one that has gained significant attention for its potential uses in various industries, including food, pharmaceuticals, and biofuels.
Chlorella is a genus of single-celled green algae belonging to the division Chlorophyta. It is spherical in shape, about 2 to 10 µm in diameter, and is without flagella. Chlorella contains the green photosynthetic pigments chlorophyll-a and -b in its chloroplasts. It was discovered in the late 19th century by a Dutch microbiologist, Martinus Willem Beijerinck.
Chlorella has been researched for its potential as a source of nutrition due to its high protein content, which can reach up to 60% of its dry weight. It also contains significant amounts of vitamins, minerals, and dietary fiber. Additionally, it is rich in omega-3 fatty acids and antioxidants such as lutein and beta-carotene. For these reasons, Chlorella has been marketed as a "superfood" and is available in various forms such as tablets, capsules, powders, and extracts.
Apart from its nutritional benefits, Chlorella has shown potential in biotechnology applications. Its high lipid content makes it a promising candidate for biofuel production. Furthermore, it has been used in wastewater treatment due to its ability to absorb heavy metals and other pollutants.
Despite these promising aspects, large-scale cultivation of Chlorella presents several challenges. These include the need for high light intensity for optimal growth and the difficulty in harvesting due to its small size. However, advances in bioreactor design and harvesting techniques have made it possible to overcome these challenges.
Other types of edible algae include Spirulina (Arthrospira), Dunaliella, and Aphanizomenon flos-aquae (AFA). Like Chlorella, Spirulina is often marketed as a superfood due to its high protein content and rich nutrient profile. Dunaliella is notable for its high beta-carotene content, which gives it a distinct red color. AFA is a type of blue-green algae that has been used as a dietary supplement due to its rich nutrient content.
In conclusion, microalgae such as Chlorella offer significant potential for use in various industries due to their high nutrient content and other beneficial properties. Despite the challenges associated with their cultivation, continued research and technological advancements are making it increasingly feasible to harness their potential on a large scale.