Production and application of microbial cellulose

Cellulose, the basic material of all plant substance, is also produced by green algae (Valonia) and some bacteria, principally of the genera Acetobacter, Sarcina and Agrobacterium. Special attention has been given to strains from Acetobacter, specially Acetobacter xylinum. Acetobacter strains are well known for oxidizing alcohols to acids and ketones, especially for the production of vinegars using ethanol, wine or cider as carbon sources. The formation of the cellulose pellicle occurs on the upper surface of the supernatant film. Cellulose production was reported to be stimulated by addition of lactic acid, methionine, tea infusion and corn steep liquor. Although for the production process new non-conventional bioreactors have been developed, static cultures are still preferred. A large surface area is important for a good productivity. Relatively low glucose concentrations also gave better productivity and yields than higher ones. Bacterial cellulose can be applied in areas where plant cellulose can hardly be used. New applications were described as thickener to maintain viscosity in food, cosmetics, etc., as nonwoven fabric or paper for old document repair, as food additives and others. We could make use of cellulose films as a temporary substitute for human skin in the case of burns, ulcers, decubitus and others. Biofill(R), Bioprocess(R) and Gengiflex(R) are products of microbial cellulose that now have wide applications in surgery and dental implants. (C) 1998 Published by Elsevier Science Limited. All rights reserved.