Author/Authors :
Yori Juan C. نويسنده , Aimaretti Nora R نويسنده , Clementz Adriana L نويسنده , Manuale Debora نويسنده Facultad de Ingenieria Quimica - Instituto de Investigaciones en Catilisis y Petroquimica Universidad Nacional del Litoral -CONICETSanta FeArgentina , Codevilla Agustin نويسنده Laboratorio de Investigaciones Aplicadas - Facultad de QuimicaUniversidad del Centro Educativo LatinoamericanoRosario
Abstract :
Discarded carrots are a valuable source of
biomass amenable for valorization. Their use as raw
material for ethanol production by fermentation, using
yeasts immobilized in Calcium alginate, was proposed. The
biocatalyst immobilization method, the existence of internal
and external mass transfer limitations, the effect of the
initial pH and the reuse of immobilized yeasts were particularly
evaluated. Results indicate that beads made with a
2 % solution of Sodium alginate and a 30 % solution of
Saccharomyces cerevisiae were strong enough to allow an
efficient nutrient transfer into the matrix and to prevent cell
leaking. A stirring rate of 200 rpm was needed to avoid
external mass transfer limitations. These beads were used
in three successive fermentations. An initial pH of 5.5
reached the best fermentation parameters. Non-enriched,
non-sterile carrot must was fermented through immobilized
yeasts; and values of ethanol concentration (29.9 g L-1),
Yp/s (0.409 g g-1), and productivity (7.45 g L-1 h-1) were
obtained. These values were similar to those registered
when free cells were used.