Inexpensive supplements such as corn steep liquor
(CSL) have been substituted for expensive nitrogen
supplements in pentose fermentation mediated by
strains of P. stipitis and C. shehatae (Sreenath and Jeffries,
1996; Amartey and Je€ries, 1994). In the work
reported here, both CSL and molasses were employed in
the fermentation of wood hydrolyzates. Addition of
corn steep liquor alone to the hydrolyzate did not support
yeast growth and fermentation, whereas addition of
molasses supported slow growth and delayed fermentation
(data not shown). At the end of fermentation (205
h), ethanol concentration was 26.5 g/l.
3.4.5. Effect of cell recycling
Fresh cells of C. shehatae FPL-Y-049 exhibited delayed
growth and fermentation in some of these batches
of partially deacidified wood hydrolyzate up to 46 h.