129. White, D. G. and R. M. Brown, Jr. 1989.
Prospects for the commercialization of the biosynthesis of microbial
cellulose. In: Cellulose and Wood -Chemistry
and Technology, Ed. C. Schuerch. John Wiley and
Sons, Inc. N. Y., 573-590.
129. Synopsis
Commercial applications of microbially derived
cellulose have only recently been explored. Cellulose biosynthesis
by the bacterium Acetobacter xylinum has distinctive advantages
over traditional sources: no delignification is required following
harvest; the product can be synthesized directly into an extremely
strong non-woven "textile" of virtually any shape; the
physical properties of the cellulose such as crystallinity, hydrophilicity,
and degree of polymerization, can be controlled during synthesis;
and, the cellulose can be produced from a wide variety of substrates.
The ability to alter physical characteristics of the cellulose
in situ may provide an efficient method for producing a
broad array of value-added products. The development of a commercially
feasible fermentation system for producing Acetobacter cellulose
presents a significant technological challenge. Large-scale fermentation
is complicated by a number of phenomena associated with the biology
of acetic acid bacteria including strain instability, the synthesis
of gluconic acid as a significant by-product, and poor oxygen
diffusion through the cellulose product of this strictly aerobic
bacterium. Pressure-cycle or dual hollow fiber (DHF) fermenters
may eliminate or reduce many of the problems encountered in producing
large quantities of microbial cellulose. Further commercialization
of Acetobacter cellulose will depend upon the successful
integration of various technical and economic elements including
market requirements, end-product characteristics, fermenter design
and operating conditions, cost and availability of substrates,
and geographic location. The ultimate promise of Acetobacter
is the ability to take advantage of the rich scientific and technological
knowledge base associated with it for the development of a commercial
scale cell-free cellulose biosynthetic system. Such a system
might allow the production of an even wider variety of cellulose
based products with even greater efficiency, thus preserving valuable
natural resources.