FORMATION of bacterial cellulose in cell-free fractions of homogenates of Acetobacter xylinum, supplemented by either adenosine triphosphate1,2 or uridine diphosphoglucose3, has recently been reported. Such homogenate fractions are necessarily complex, and unequivocal identification of the immediate precursor of cellulose might be easier if a cell-free extract of cultures of this bacterium, which retains the capacity to form cellulose, could be prepared. This communication describes the preparation of such an extract.