Cover photograph (Copyright © 2006, American Society for Microbiology. All Rights Reserved.): Scanning electron micrograph of an Alcanivorax borkumensis SK2 mutant overproducing polyhydroxyalkanoate during growth on n-octadecane. Disruption of a “tesB-like” acyl-coenzyme A thioesterase gene results in overproduction and extracellular deposition of this biotechnologically important biopolymer. (Photo courtesy of Heinrich Lünsdorf, HZI Braunschweig.) (See related article on page 8452.)