Cultivation For seed culture, 70 ml of HS medium
in a 500 ml Erlenmeyer flask was inoculated with 1.8 ml
of cell suspension stored at -80°C and incubated on a
rotary shaker (150 rpm) for 36 h at 30°C. This culture
was treated with 0.1% cellulase (celluclast, Novo Nordisk
Co., Denmark) for 24 h in order to hydrolyze the
cellulose produced. The cells were harvested by centrifugation
at 8,000 x g to remove the added cellulase and
then resuspended in fresh medium. Main cultures were
performed in flasks and a jar fermentor. Flask cultures
were performed in 500 ml Erlenmeyer flasks containing
70ml HS medium for 6 d at 30°C in a rotary shaker
(15Orpm). A 5 I jar fermentor (KMJ-SC, Mitsuwa Co.)
containing 2 1 of medium was used at 30°C and pH 5.0
under aeration of 0.25 vvm. Agitation speed was initially
controlled at 500rpm during the lag phase and then
increased to 1,000 rpm. The concentrations of carbon
dioxide and oxygen in the exhaust gas were measured
using a carbon dioxide and oxygen analyzer (FOCA-1,
TOA Electronics Ltd.).