Spherulites ef Bacterial Cellulose Acetobacter xア1伽脚

Two　dimensional　spherulites　are　formed　in　the　pellicle　of　bacterial　cel｝ulose　by statlc　cultures　of　Acetobacter　xylinum．　These　spherulites　are　much　larger（sometirnes more　than　2　cm　in　diameter）than　those　usually　observed　in　other　natural　or　synthetic polymers．　Evldence　from　polarizing　and　phase　rRicroscopy　as　well　as　scanning　electron microscopy　indicates　that　the　cellulose　microfibrils　in　the　spherulites　of　bacterial cellulose　are　oriented　tangentially　and　not　radially．　Also，　the　orientation　may　be limited　to　only　a　fraction　of　the　thickness　of　the　pellicle．　lt　is　suggested　that　the tangential　deposition　may　be　caused　by　a　gradient　of　concentration　of　a　weakly