Preparation of inoculum
The inoculum was prepared in 100 ml growth medium (as men-tioned above but without agar) taken in sterilized (at 121 C for
20 min) 250 ml Erlenmeyer flask. The flask was inoculated with a
loopful of the S. cerevisiae culture and incubated for 24 h at 30C
at 120 rpm in an orbital shaker incubator (Remi Pvt. Ltd., Bombay,
India). This served as the inoculum for free cells for ethanol
production.
For immobilized cells, 60 ml of yeast inoculum [equivalent to
10% of the fermentation medium (600 ml)] was immobilized with
the luffa discs as the matrix described in the following section.