American Scientist

November-December 2011

Volume: 99 Number: 6

Algae frequently are heralded as future feedstocks for biofuels, alternatives to the fossil fuels that so much of the world depends on even though their combustion keeps pumping greenhouse gases into Earth's atmosphere. The freshwater algae Botryococcus braunii, shown on the cover, are one type of microalgae that attract a lot of interest because of their adaptability and their relatively high lipid content. Found in environments as diverse as continental, temperate, alpine and tropical climate zones, the species is a particularly adept producer of hydrocarbons. As Philip T. Pienkos, Lieve Laurens and Andy Aden explain in "Making Biofuel from Microalgae," multiple scientific, environmental and economic challenges must be overcome before algae-based fuels bloom into a large-scale energy source. (Photograph by Roland Birke / Oxford Scientific.)