AbstractCellulose is the most abundant biological polymer on Earth. It is found in wood and cotton, and forms the basic structural foundation of the cell wall of almost all eukaryotic plants. Bacteria are known to secrete cellulose as part of their metabolism of glucose and other sugars. The focus of this review is upon bacterial cellulose synmesis. We emphasize recent literature directed primarily uponAcetobacter xylinumwhich has been most widely studied. Our review covers die following topics relating to cellulose synthesis: genetics, biochemistry, ultrastructure, growth conditions, and ecological considerations as they relate to the diversity of microbes capable of synthesizing this abundant, unique polymer–cellulose.