Gluconacetobacter xylinus (Ga. xylinus) is a Gram negative bacterium which can produce an extracellular polysaccharide called bacterial cellulose. This material potentially has a wide range of applications in the food industry and other fields. In addition to fresh fruits, Kombucha, a Chinese traditional beverage fermented from tea and sugar, is also known to be one of the habitats of Ga. xylinus. Despite this, almost all previous studies on bacterial cellulose production have used Ga. xylinus strains isolated from fresh fruit sources and Kombucha strains of this species have not been extensively characterized for bacterial cellulose production. It is hypothesized that as is the subject of long-term sub-culture under static conditions, Ga. xylinus strains from Kombucha may have different cellulose producing characteristics than those typically encountered from other sources. Although bacterial cellulose has been applied in various fields, the use of bacterial cellulose thus far remains unexploited in the area of active package production. We, therefore, have undertaken this study to (i) characterize and improve cellulose production by a strain of Ga. xylinus (K3) previously isolated in our laboratory from Kombucha, (ii) develop a new application of bacterial cellulose as an active food packaging material and (iii) investigate the occurrence of spontaneous mutations in cellulose synthesis in Ga. xylinus K3 as this may impact on cellulose production. In order to characterize cellulose production by Ga. xylinus K3, cellulose yield in tea medium with both black tea and green tea, and in Hestrin-Schramm (HS) medium under both static and agitated culture, was initially compared. In tea medium the highest cellulose yield was obtained with green tea (~0.20 g l-1) rather than black tea (~0.14 g l- 1). The yield in HS was higher (~0.28 g l-1) but did not differ between static and agitated incubation. 1H NMR and 13C NMR spectroscopy indicated that the cellulose produced is pure (free of acetan) and has high crystallinity, ...