Another factor that lead to increase of microbial cellulose production in RDR is the larger surface area. The cellulose production was found to be proportional to the surface area of the culture when volume were held constant [8]. In RDR, the surface area for cellulose to attach on are higher compared to static fermentation. In this study, with good discs packing, active surface area of RDR can form up to 2.5 times compared to static fermentation. Therefore, it is demonstrated that fermentation using RDR give better cellulose yield compared to static fermentation. These phenomena are due to the fact that RDR gives better aeration for microbial cellulose production and at the same time provides larger surface area for liquid-air interface.