A method for direct harvest of bacterial cellulose filaments during continuous cultivation of Acetobacter xylinum

Continuous filamentation of bacterial cellulose (BC) was successfully achieved by using shallow pan for the incubation to regulate thickness of the BC gel produced by Acetobacter xylinum. The BC filament was harvested and prepared directly by picking up BC pellicles, the thin BC gel, and winding slowly from the surface of the culture medium passed through a preliminary bactericidal washing bath. The X-ray diffraction analysis and scanning electron microscopic observation of the BC filament thus obtained showed that the filament was smooth and the fairly good orientation of BC molecules. The average tensile strength was 4.4 g denier(-1) for the filament prepared by hot alkaline treatment and subsequent washing with distilled water and dried under tension (Filament W): 3.4 g denier(-1) for washing with 10% aqueous ethylene glycol after alkaline treatment followed by drying under tension (Filament E) and 2.4 g denier(-1) for the treatment with 10% ethylene glycol after normal water-washing followed by drying under tension. (C) 1998 Elsevier Science Ltd. All rights reserved.