Spent yeast samples (yeast cell slurry deposited at the
bottom of ethanol fermentation tanks inoculated with
Sachharomyces cereviceae) were provided by Bannari
Amman Distilleries, Modur, and Erode. The slurry collected
was centrifuged at lab level (6000 rpm for 10 min)
and the resultant cell pellet was washed twice with water
to discard chemical residues settled along with cells. This
washed spent yeast cells were introduced to pressmud
at 10% (w/w) (if there was variation in inoculum percentage,
the same was specifically mentioned) as inoculum.
A local isolate of S. cereviceae maintained in YDP slants
was used as fresh cultured yeast (2 loops of the yeast
transferred to 50 mL of YDP broth held in 250 mL conical
flask and incubated at 120 rpm for 24 h) wherever added
as part of the inoculum. This culture was maintained as
glycerol stock in glycerol: water (1:1) mix at −20°C. Sub
cultures were made by streaking on to YDP agar.