Structure of nascent microbial cellulose VI. Influence of positions of sulfonate groups in Fluorescent Brightener on crystal structure of microbial cellulose

The influence of the number of sulfonate groups in a Fluorescent Brightener with 2 (FB) or 4 sulfonate groups (FWA1 with 2 sulfonate groups at the met a position of the phenylamino ring and FWA2 with 2 groups at the para posit ion) and positions on the crystal structure of microbial cellulose was exam ined by X-ray diffraction and solid state C-13 NMR spectroscopy. All produc ts obtained from Acetobacter xylinum culture in the presence of each Fluore scent Brightener were crystalline complexes containing ct dye between cellu lose sheets corresponding to the (ITO) planes of microbial cellulose. Cellu loses regenerated from FB or FWA1-cellulose complexes formed cellulose Ip r ich structures, whereas cellulose regenerated from FWA2-cellulose complex f ormed cellulose II. Even if a Fluorescent Brightener had the same number of sulfonate groups, the effects on the crystal structure of regenerated micr obial cellulose clearly differed according to position.