Rhodobacter sphaeroides was originally identified by van Niel as a non-sulfur purple photosynthetic bacterium, which is now recognized as belonging to the alpha class of gram-negative species. It is one of the most versatile and thoroughly-studied species of its kind, capable of growing photoheterotrophically on a variety of compounds and is often used in bioremediation. The SE1 strain was recently isolated and purified from the San Elijo Lagoon in SanDiego, CA.