title: Influence of aeration on bioethanol production from ozonized wheat straw hydrolysates using Pichia stipitis.
abstract: The influence of aeration on ethanol production by Pichia stipitis was studied in wheat straw hydrolysates subjected to ozone pretreatment for the first time. In a first stage, different aeration rates ranging from 0.03 to 0.50 L air/min, which corresponds to a volumetric oxygen transfer coefficient from 1.1 to 9.6 h(-1), were applied to model glucose/xylose substrates. The most promising value was found to be 3.3 h(-1) (0.1 L air/min) leading to better xylose utilization, an ethanol yield of 0.40 g ethanol/g sugars and complete depletion of sugars at 72 h. In a second stage, the effect of aeration was analyzed in ozonized wheat straw hydrolysates. Sugars were completely depleted at 96 h and ethanol yield reached a value of 0.41 g ethanol/g sugars. The addition of controlled oxygen (K(L)a=3.8 h(-1)) enhances the efficiency of the process causing an increase of 29.1% in ethanol production and a considerable reduction of 42.9% in fermentation time as compared to non-aerated hydrolysates.
authors: Department of Chemical Engineering and Environmental Technology, University of Valladolid, Valladolid, Spain.
authors: Carolina
authors: C
authors: Bellido
authors: Gerardo
authors: G
authors: González-Benito
authors: Mónica
authors: M
authors: Coca
authors: Susana
authors: S
authors: Lucas
authors: María Teresa
authors: MT
authors: García-Cubero
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000332:Aerobiosis / Q000187:drug effects; D056804:Biofuels / Q000382:microbiology*; D018533:Biomass; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D019815:Oxalic Acid / Q000494:pharmacology; D010126:Ozone / Q000494:pharmacology*; D010843:Pichia / Q000187:drug effects / Q000378:metabolism*; D014908:Triticum / Q000737:chemistry*; D014866:Waste Products / Q000032:analysis*; D014993:Xylitol / Q000096:biosynthesis
chemical_list: D056804:Biofuels; D014866:Waste Products; D000431:Ethanol; D010126:Ozone; D019815:Oxalic Acid; D019342:Acetic Acid; D014993:Xylitol