DESIGNING ECONOMICAL PRODUCTION OF MICROBIAL CELLULOSE FROM WASTE USING MODIFIED BIOREACTOR Khairul Azly Zahan*, Mohd Fadhrullah Mohd Sani, Norhayati Pa’e, Ch’ng Chia Hui and Ida Idayu Muhamad Department of Bioprocess Engineering, Faculty of Chemical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor Abstract. Microbial cellulose produced by Acetobacter xylinum is an alternative source for plant cellulose in industrial use. Production of microbial cellulose is receiving great attention since they can be applied in many fields. This research is carried out to study the production of microbial cellulose using Rotary Discs Reactor (RDR) by Acetobacter xylinum bacteria in pineapple waste medium. RDR is a new method developed to enhance the production of microbial cellulose in industrial field because of few advantages: it allows the oxygen enrich air to be supplied continuously, homogenized culture in the medium by rotating discs and less hassle to scale up. This research involved few experimental works including fermentation process, comparison of the production yield from static culture and RDR using similar medium, and glucose analysis. The fermentation process was carried out at room temperature, pH 5.0, rotary speed at 7 rpm and 4 days of fermentation. The variable parameter in this research was waste pineapple concentration which varied from 20% (v/v) to 100% (v/v). Results show that microbial cellulose production in the medium with 20% (v/v) of waste pineapple concentration was the highest value which is 255.85 gram among others. Keywords: Microbial Cellulose, Acetobacter xylinum, modified bioreactor, waste to wealth 1.0 INTRODUCTION Nowadays, the most usual method for production process of microbial cellulose had used static cultivation methods, with pellicles of microbial cellulose being formed on the surface of the static culture. But, there are some issues that prevented larger scale production as high price substrates, low volumetric yields, long time consumption, laborious and the up-scale process for high yield is limited. Studies showed that there is an alternative method to improve this problem by using Rotary Discs Reactor (RDR). This research is focused on the evaluation on static culture and using Rotary Disc Reactor in production of microbial cellulose from different concentration of pineapple waste to ensure high yield and high quality of microbial cellulose produced. The RDR use the concept of rotating biological contactor that exposed bacteria to the air for better aeration and used multiple discs that rotate to give better aeration to the bacteria (Norhayati, 2009). In this study, pineapple waste had been used as a subtrate to produce microbial cellulose. In pineapple industries, only 20% were used to produce product while another 80% is the waste. A method of turning this waste to wealth is producing microbial