Microalgae: Production, Consumption and Challenges

Microalgae are the unicellular, autotrophic organisms present in marine or fresh water environment. They may be present as single cell or in the form of colonies. Microalgae are the source of various substances that are beneficial for health like proteins, lipids, lutine, precursors of vitamins, carotenoids and vitamin A, B1, B3, B6, B12, E. Furthermore, the use of microalgae for medicinal purposes can be traced back to ancient Chinese medicines due to their antibiotic, antimycobacterial, antiviral, anti-inflammatory, analgesic, antipyretic, antiproliferative, and cytotoxic activities. Recent advances in science and technology have revealed the drawback of using synthetic products for health and environment. This revelation has compelled people to use natural products. With the increasing trend of organic products in every sector of life and their benefits over synthetic products, utilization of microalgae has also gain popularity in various sectors viz., food, pharmaceuticals, cosmetics, cosmeceuticals, biofuel, biofertilizers, bioplastics, waste water treatment, aquaculture etc. Products from microalgae help preserving the environment and reduction of environmental pollution. Microalgae are also useful in bioremediation of heavy metals like; mercury, lead, chromium, cadmium and arsenic from water. One of the examples of utilization of microalgae as food is Spirulina, which is now commercially available in the form of powder and tablets. It is known as super food because of its high macro and micronutrient content. It is also used and feed for domestic animals and fish. Other commercially grown microalgae include Chlorella, Skeletonema, Tetraselmis, Isochrysis, Pavlova, Phaeodactylum, Chaetoceros, Nannochloropsis, Oscillatoria etc. For the commercial utilization, microalgae can be cultivated in open ponds (circular ponds or raceways), closed ponds (tubular or flat-plate photobioreactors) or in natural water bodies then harvested and processed for respective use. Despite of their utilization in various products, microalgae cultivation faces many challenges like high production and maintenance cost, contamination by other microorganisms. To overcome these challenges further research and development of more cost effective and efficient methods are required.