Development
of an efficient consolidated process is pivotal in
order to design industrially viable processes for conversion of lignocellulosic
biomass into second generation (2G) ethanol. Aiming to develop process
consolidation, here we explored fluidized bed reactor (FBR) for 2G
ethanol production from sugar cane bagasse hemicellulosic hydrolysate
(SBHH) employing calcium alginate immobilized cells of Scheffersomyces
shehatae UFMG-HM 52.2. A 22-full factorial design
of experiments was carried out in order to evaluate the effect of
aeration rate (0.027, 0.069, and 0.111 min–1) and
carrier concentration (55.55, 83.33, and 111.11 g. L–1) on the ethanol yield (Y
P/S) and productivity
(Q
P). Both process variables, when used
at the highest level (aeration, 0.11 min–1; immobilized
carrier concentration, 111.11 g. L–1), showed maximum
ethanol production (Y
P/S, 0.26 g/g and Q
P 0.17 g·L–1·h–1). Results showed the potential to use this immobilized
yeast in a fluidized bed reactor for ethanol production from C5 sugar
solution. Repeated batch fermentations in FBR showed stable ethanol
yield during 6 batches (288 h) followed by a gradual decrease. The
use of immobilized cells in FBR could be conducive to the development
of viable 2G ethanol production processes. To the best of our knowledge,
this is the first report on 2G ethanol production from immobilized S. shehatae cells employing FBR using SBHH.