Mixtures of glucose and fructose in a ratio of 1 : 3
comprising 2% (w/v) of medium were used as carbon
sources to compare the fermentation profiles of glucose
alone and fructose alone. As shown in Fig. 7 and Table
2, the process comprised the steps: (a) Lag phase or
induction phase (O-32 h) in which added glucose was converted
completely to gluconic acid but fructose was not
utilized. (b) Cell growth/cellulose production phase (32-
44 h) in which cellulose was produced mainly by utilizing
fructose and, simultaneously, accumulated gluconic acid
was partially consumed. (c) Stationary phase (45-60 h) in
which the carbon source was limited but gluconic acid was maintained at a concentration of 3 g/l.