It is interesting that when glucose coexists with fructose
in the CSL medium, BRCS preferentially metabolizes
glucose to gluconic acid and then synthesizes cellulose
mainly by consuming fructose. When glucose alone
exists in the CSL medium, cellulose is begun to be
produced after almost all glucose is converted to gluconic
acid. It was concluded from both cases that cellulose
could be synthesized under conditions of limited glucose.
Kamide et al. (11) reported that cellulose was produced
exponentially after an inductive cultivation period
(25 h). Our results concurred with this finding. Approximately
one day inductive period was observed in our
experiments regardless of the carbon sources, and the
overall cellulose productivity was low, as shown in
Table 2. The reduction of lag period is important to
enhance overall productivity of cellulose in batch cultures.
Further research on this problem is required.