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 meta position of the phenylamino ring and FWA2 with 2 groups at the para position) and positions on the crystal structure of microbial cellulose was examined by X-ray diffraction and solid state C-13 NMR spectroscopy. All products obtained from Acetobacter xylinum culture in the presence of each Fluorescent Brightener were crystalline complexes containing ct dye between cellulose sheets corresponding to the (ITO) planes of microbial cellulose. Celluloses regenerated from FB or FWA1-cellulose complexes formed cellulose Ip rich structures, whereas cellulose regenerated from FWA2-cellulose complex formed cellulose II. Even if a Fluorescent Brightener had the same number of sulfonate groups, the effects on the crystal structure of regenerated microbial cellulose clearly differed according to position.