In this study, industrial starchy food wastes were characterized
and evaluated as substrates for butanol production. Butanol and
ABE yields obtained on starchy food wastes were in fact similar
or better than those obtained when C. beijerinckii NCIMB 8052
was grown on glucose (in this study). In addition, ABE titers and
yields reported herein compare favorably to previous reports by
the same or different solventogenic species/strains on crude carbohydrates
substrates. Taken together, we have demonstrated that
industrial starchy food waste is a feasible alternative substrate
for fermentative production of butanol given the impact of substrate
cost on the overall production cost of biobutanol. Further,
the energy content and global abundance of starchy food wastes
make them ideal for use as potential feedstocks for the production
of biobutanol. Considering that ABE fermentation is product limiting
due to the toxicity of butanol to the fermenting organism,
future work will focus on ameliorating butanol toxicity effects to
C. beijerinckii NCIMB 8052 during growth on these food wastes
by incorporating simultaneous in situ butanol recovery, such as
gas stripping, during fermentation.