Título
Hydrolysis ofAgave fourcroydesLemaire (henequen) leaf juice and fermentation with Kluyveromyces marxianusfor ethanol production
Autor
LUIS FELIPE BARAHONA PEREZ
Nivel de Acceso
Acceso Abierto
Materias
Resumen o descripción
arbon sources for biofuel production are wide-ranging and their availability depends on the climate
and soil conditions of the land where the production chain is located. Henequen (Agave fourcroydesLem.) is
cultivated in Yucatán, Mexico to produce natural fibers from the leaves, and a juice containing fructans
is produced during this process. Fructans can be hydrolyzed to fructose and glucose and metabolized into ethanol
by appropriate yeasts. In Mexico, differentAgavespecies provide the carbon source for (distilled and non-distilled)
alcoholic beverage production using the stem of the plant, whilst the leaves are discarded. In this work, we
investigated the effect of thermal acid and enzymatic hydrolysis of the juice on the amount of reducing sugars
released. Growth curves were generated with the yeasts Saccharomyces cerevisiaeandKluyveromyces marxianusand
fermentations were then carried out with Kluyveromyces marxianusto determine alcohol yields.
Results:With thermal acid hydrolysis, the greatest increase in reducing sugars (82.6%) was obtained using 5%
H2SO4at 100°C with a 30 min reaction time. Statistically similar results can be obtained using the same acid
concentration at a lower temperature and with a shorter reaction time (60°C, 15 min), or by using 1% H2SO4
at
100°C with a 30 min reaction time. In the case of enzymatic hydrolysis, the use of 5.75, 11.47 and 22.82 U of
enzyme did not produce significant differences in the increase in reducing sugars. Although both hydrolysis
processes obtained similar results, the difference was observed after fermentation. Ethanol yields were 50.3 ± 4
and 80.04 ± 5.29% of the theoretical yield respectively.
Conclusions:Final reducing sugars concentrations obtained with both thermal acid and enzymatic hydrolysis were
similar.Saccharomyces cerevisiae, a good ethanol producer, did not grow in the hydrolysates. Only Kluyveromyces
marxianuswas able to grow in them, giving a higher ethanol yield with the enzymatic hydrolysate. The leaves
account for a non-negligible weight of the total agave plant biomass, so this work complements the knowledge
already developed on agave fermentations by making it possible to produce ethanol from almost the entire plant
(stem and leaves)
Fecha de publicación
14 de febrero de 2014
Tipo de publicación
Artículo
Recurso de información
Formato
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Repositorio Orígen
Repositorio Institucional CICY
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