The research on using wood flour hydrolysate as carbon source to produce bacterial cellulose

摘要

Bacterial Cellulose (BC), a kind of nano-biomaterial, is produced by some microorganism. It is of particular network structure which is composed of ultra-fine ribbon-shaped fibers. In comparison with plant cellulose, BC displays high purity, high crystallinity, high water-holding capacity, biocompatibility, high mechanical strength and controllability during the course of biosynthesis and so on. Therefore, BC can be used in areas where plant cellulose can hardly be used. Nowadays BC has been one of the most active topics in the materials field. At present, there are some problems about the production and application of bacterial cellulose in China. This paper regarded acetobacter xylinum selected by the laboratory as the experimental strains, and explored the fermentation conditions that it used wood flour hydrolysate of poplar as carbon source to produce bacterial cellulose. The optimal culturing conditions for acetobacter xylinum statically producing bacterial cellulose under cultivation and fermentation are: the age of the seed solution is 24h; the cultivation temperature is 30°C; the inoculum size is 8%; the fermentation period should be controlled within 6 days; the initial pH value is 6.0. The wood flour of poplar needs pretreatment of ball-milling, when the enzyme concentration is 30mg/ ml, the temperature is 50°C, pH value is 6.0 and the time is 5 hours. It has a maximum absorbance at the place of 540nm, and by calculation the acid hydrolysis degree is 38%. When the content of wood flour is 18g/L and the content of glucose is 14g/L, it can produce the maximum bacterial cellulose.