Microalgae are basically unicellular organisms, so small that it can only be viewed under a microscope. Compared to macroalgae which are structurally more complex consisting of different cells with its own functions and purposes, microalgae in general has only basic cell construction which is just enough to ensure their survival. There are different types and varieties and among their own individual grouping, you can even sub-divide the species into several strains.
There are generally two main microalgae groups, the first one is known as “Diatoms” and another is the “Dinoflagellates”. Both of them share several common traits or properties like for example being free-floating in water is particularly important to allow these microorganisms to gain maximum exposure to sunlight whereby buoyancy is assisted by the presence of oil in their cell structure (this is what we extract for biofuel production). Also their simple cell structures have allowed the cells to propagate quickly which again is another important trait that will qualify microalgae as a feasible and economically-viable renewable energy source. One of the traits that set both them apart is basically on the mobility part in which the Dinoflagellates have flagella to help them move through water.
Microalgaes can also be categorized depending on the environment where they live in. Some are endemic depending on the availability and combination of nutrients present in that locality which are available to support their growth. Although common strains are found in freshwater environment, most of the commercially pure cultures are extracted for use as feed stock in the saltwater aquaculture industry. Microalgaes can also be classified based on their color and among those; the green algae are the ones at the center of our attention here. Some of the red and brown algae although are sometimes incorrectly classified belonging to the Diatoms and Dinoflagellates groups, these species are not free-floating in water and will provide lower yield which in economic sense will only interfere in the production of commercial biofuel. Despite sharing common traits, the challenges when it comes to finding the perfect strain for use in the biofuel industry is about locating one that give the highest yield per acre of land and produced in the shortest period of time.
