title: Continuous Fermentation of Wheat Straw Hydrolysate byClostridium tyrobutyricumwith In-Situ Acids Removal.
abstract: The present study focused on fermentative butyric acid production byClostridium tyrobutyricumfrom pre-treated and hydrolysed wheat straw (PHWS) based on continuous operation mode and in situ acids extraction by reverse electro enhanced dialysis (REED). Different dilutions of PHWS in a synthetic medium (60-100 % v/v) were tested. It was found that continuous fermentation of PHWS greatly enhanced the sugar consumption rates and butyric acid productivity compared to batch tests, while application of REED enhanced them even further. Specifically, applying combined continuous operation mode and REED system for the fermentation of 70 % PHWS resulted in 19- and 53-fold higher glucose (1.37 g L-1h-1) and xylose (0.80 g L-1h-1) consumption rates, respectively, compared to those obtained by batch processing. Fermentation of 100 % PHWS continued unhindered with just urea and K2HPO4added with butyric acid production rate, yield and selectivity being 1.30 g L-1h-1, 0.45 g g-1sugars and 0.88 g g-1acids, respectively. These results were also confirmed in a 20 L pilot plant bioreactor system.
authors: Department of Chemistry and Bioscience, Section for Sustainable Biotechnology, Aalborg University (AAU), A C Meyers Vænge 15, 2450 Copenhagen SV, Denmark.
authors: G N
authors: GN
authors: Baroi
authors: Department of Chemistry and Bioscience, Section for Sustainable Biotechnology, Aalborg University (AAU), A C Meyers Vænge 15, 2450 Copenhagen SV, Denmark.
authors: I V
authors: IV
authors: Skiadas
authors: Department of Chemistry and Bioscience, Section for Sustainable Biotechnology, Aalborg University (AAU), A C Meyers Vænge 15, 2450 Copenhagen SV, Denmark.
authors: P
authors: P
authors: Westermann
authors: Department of Chemistry and Bioscience, Section for Sustainable Biotechnology, Aalborg University (AAU), A C Meyers Vænge 15, 2450 Copenhagen SV, Denmark.
authors: H N
authors: HN
authors: Gavala
keywords: Butyric acid; Clostridium tyrobutyricum; Fermentation; Lignocellulosic biomass; Reverse electro enhanced dialysis; Wheat straw