title: Effect of nutrient supplementation of crude or detoxified concentrated distilled grape marc hemicellulosic hydrolysates on the xylitol production by Debaryomyces hansenii.
abstract: Biosynthesis of xylitol using the yeast Debaryomyces hansenii NRRL Y-7426 was carried out using distilled grape marc (DGM) hemicellulosic hydrolysates directly concentrated by vacuum evaporation or after detoxification with activated charcoal. The effect of nutrient supplementation with vinasses, corn steep liquor (CSL) or commercial nutrients was explored. Using crude concentrated hemicellulosic hydrolysates, the maximum xylitol concentration, 11.3 g/L, was achieved after 172 hr (Q ( xylitol ) = 0.066 g/L-hr; Y ( xylitol ) (/SC) = 0.21 g/g); meanwhile, using detoxified concentrated hydrolysates, the concentration increased up to 19.7 g/L after 72 hr (Q ( xylitol ) = 0.274 g/L-hr; Y ( xylitol ) (/SC) = 0.38 g/g). On the other hand, using crude or detoxified hydrolysates, the xylose-to-xylitol bioconversion was strongly affected by the addition of nutrients, suggesting that these hydrolysates present essential nutrients favouring the growth of D. hansenii.
authors.affiliation: Department of Chemical Engineering, University of Vigo (Campus Ourense), Spain. jmanuel@uvigo.es
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Salgado
authors.forename: Noelia
authors.initials: N
authors.lastname: Rodríguez
authors.forename: Sandra
authors.initials: S
authors.lastname: Cortés
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Domínguez
mesh_terms: D002606:Charcoal / Q000737:chemistry; D003470:Culture Media / Q000737:chemistry*; D055165:Debaryomyces / Q000737:chemistry / Q000378:metabolism*; D000431:Ethanol / Q000737:chemistry; D005285:Fermentation; D005502:Food; D006868:Hydrolysis; D011134:Polysaccharides / Q000737:chemistry* / Q000378:metabolism; D027843:Vitis / Q000737:chemistry / Q000382:microbiology*; D014993:Xylitol / Q000096:biosynthesis*; D003313:Zea mays / Q000737:chemistry
chemical_list: D003470:Culture Media; D011134:Polysaccharides; D002606:Charcoal; D000431:Ethanol; C007916:hemicellulose; D014993:Xylitol