Cellulose production by Acetobacter xylinum BRC5 under agitated condition

A potent cellulose producer, Acetobacter xylinum BRC5, was cultivated in shaking flasks and jar fermentors with glucose, fructose, sucrose and mixtures of these as carbon sources. It was confirmed that corn steep liquor (CSL) was cheap and a suitable organic nitrogen source for cellulose production by strain BRC5. When glucose was used as a sole carbon source, strain BRC5 oxidized almost all the glucose to gluconic acid, thereafter it biosynthesized cellulose by utilizing the gluconic acid accumulated in the broth under limited glucose conditions. Since strain BRC5 did not metabolize fructose to acid, the fermentation pattern of fructose was found to be typically growth associated with cellulose production. However, when glucose and fructose coexisted in the medium, strain BRC5 preferentially metabolized all the glucose to gluconic acid. Thereafter, it produced cellulose mainly by utilizing fructose. Overall cellulose productivity in a jar fermentor ranged from 0.071 to 0.086 g/ l/h.