Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.5/5302
Título: Otimização da produção de xilitol por estirpes de Debaryomyces hansenii em hidrolisado de Arundo donax
Autor: Bandeira, Filipa de Sousa
Orientador: Duarte, Luís Jorge Quelhas
Martins, Maria Luísa Louro
Palavras-chave: Arundo donax L.
diluted acid hydrolysis
particle size
microbial acclimatization
Debaryomyces hansenii
xylitol
Data de Defesa: 2012
Editora: ISA/UTL
Citação: Bandeira, F.S. - Otimização da produção de xilitol por estirpes de Debaryomyces hansenii em hidrolisado de Arundo donax. Lisboa: ISA, 2012, 116 p.
Resumo: Arundo donax L. is a Mediterranean energy crop with a high potential for the production of bioenergy and added-value products. Nevertheless, its exploration within a biorefinery framework still requires further developments. This work aims to contribute for the development of a strategy to upgrade its hemicellulose fraction, by means of xylitol bioproduction. The raw material was milled and the influence of particle size on acid hydrolysis was studied. The composition of the hydrolysates and residual solids obtained did not differ significantly for the different fractions tested (< 2 mm). Three Debaryomyces hansenii strains were compared in chemically defined medium (CDM), and their tolerance and acclimatization were studied using non-detoxified hydrolysate-based medium (HM). Strain CCMI 941 presented the highest xylose consumption rate (0.26 g·L-1·h-1) in CDM and the best tolerance to the HM. For this reason, this strain was selected for the optimization of the xylitol bioprocess. The best results for xylitol yield and productivity in overall process (0.77 g·g-1 and 0.09 g·L-1·h-1, respectively) were obtained under semi-aerobic conditions, using a twofold concentrated, not supplemented, non-detoxified hydrolyzate and an inoculum with a single step of acclimatization under full aerobic conditions. This yield is one of the highest reported in literature for this strain
Descrição: Mestrado em Engenharia Alimentar - Processamento de Alimentos - Instituto Superior de Agronomia
URI: http://hdl.handle.net/10400.5/5302
Aparece nas colecções:BISA - Dissertações de Mestrado / Master Thesis

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