Scientists from the Arizona State University's Biodesign Institute (United States) are working at conditions that optimize the growth of a group of microorganisms called "cyanobacteria", which are a potential source of biofuels and biochemicals. Cyanobacteria can be considered as an attractive option as a biofuel source, for the following reasons: (1) they are photosynthetic, and are able to produce "roughly 100 times the amount of clean fuel per acre compared with other biofuel crops", (2) they only need sunlight, water, carbon dioixe and a few nutrients to grow, (3) they do not compete with land that are used for food production, and can be cultivated in compact photobioreactors. According to postdoctoral research associate, Dr. Hyun Woo Kim, "Photosynthetic cyanobacteria are able to produce roughly 100 times the amount of clean fuel per acre compared with other biofuel crops". The researchers focused on the cultivation of a cyanobacterial strain, Synechocystis PC6803, in a photobioreactor. They found that phosphorus supply is an important component in the organism's ability to "make efficient use of carbon dioxide in their growth cycle". Higher biomass productivity was observed when the growth medium (called, "BG-11" medium) is supplied with additional phosphorus. "Although phosphorus content had been studied in the past with respect to the problem of eutrophication in lakes and other inland waters, its significance for controlled growth of phototrophs like cyanobacteria within a PBR (photobioreactor) had not been examined in detail". The production scenario involves the use of carbon dioxide emitted by power plants, and nutrients from wastewater streams.