Effect of acetic acid and ethanol as additives on bacterial cellulose production by acetobacter xylinum

Abstract

Bacterial cellulose was the result of fermentation by Acetobacterium xylinum. Fermentation medium that used in this research is is HS (Hestrin - Shramm) media with MgSO 4 as cofactor and also with 5% (v/v) glycerol and 0.8% (w/v) urea as additional carbon and nitrogen sources. This research focus is to determine the effect of acetic acid and ethanol as additives agent in the production of bacterial cellulose. Addition of additives to the fermentation medium aims to improve the characteristic of bacterial cellulose. Variable that used in this research is additive concentration (0.5%, 1%, 1.5%, and 2% v/v). Synthesized bacterial cellulose will be physically and mechanically characterize using dry thickness measurement, water capacity measurement, swelling ability, tensile strength and elongation at break measurement. Morphology measurement will be known through SEM (Scanning Electron Microscopy) and FTIR (Fourier Transform Infra Red) analysis. SEM analysis showed that addition of 1.5% (v/v) acetic acid to the fermentation medium gave more fiber on bacterial cellulose than addition of 1.5% ethanol, this result also supported by FTIR analysis. Rated of moisture content and swelling ratio of bacterial cellulose using 1.5% (v/v) ethanol higher when compared with 1.5% acetic acid on fermentation medium. Tensile strength and elongation at break analysis showed that bacterial cellulose has the highest tensile strength and the lowest elongation at break value with addition of 1.5% (v/v) acetic acid to the fermentation medium.