Algae are present in all existing habitats where light is available. Algae can potentially produce 1,000-4,000 gallons of oil/acre/yr, which is significantly higher than soybeans (48 gallons of oil/acre/yr) and other oil crops. Algae are not traditional foods or feeds. They can be cultivated in large open ponds or in closed photobioreactors located on non-arable land, and can grow under a wide variety of climate and water conditions.
There are four major types of cultivation conditions for algae: photoautotrophic, heterotrophic, mixotrophic and photoheterotrophic cultivation. Photoautotrophic cultivation occurs when algae use light as the energy source, and inorganic carbon (e.g. carbon dioxide) as the carbon source to form chemical energy through photosynthesis. This is the most commonly used cultivation condition for algae growth. When algae use organic carbon as both the energy and carbon sources, it is called heterotrophic cultivation. Mixotrophic cultivation is that algae use both organic compounds and inorganic carbon as carbon sources for growth. This means that the algae are able to live under either phototrophic or heterotrophic conditions, or both. Photoheterotrophic cultivation is that algae require light when using organic compounds as the carbon source. The main difference between mixotrophic and photoheterotrophic cultivations is that the latter requires light as the energy source, while mixotrophic cultivation can use organic compounds to serve this purpose.
Last date updated on June, 2014