title: Biorefinery of the green seaweedUlva lactucato produce animal feed, chemicals and biofuels.
abstract: The growing world population demands an increase in animal protein production. Seaweed may be a valuable source of protein for animal feed. However, a biorefinery approach aimed at cascading valorisation of both protein and non-protein seaweed constituents is required to realise an economically feasible value chain. In this study, such a biorefinery approach is presented for the green seaweedUlva lactucacontaining 225 g protein (N× 4.6) kg-1dry matter (DM). The sugars in the biomass were solubilised by hot water treatment followed by enzymatic hydrolysis and centrifugation resulting in a sugar-rich hydrolysate (38.8 g L-1sugars) containing glucose, rhamnose and xylose, and a protein-enriched (343 g kg-1in DM) extracted fraction. This extracted fraction was characterised for use in animal feed, as compared toU. lactucabiomass. Based on the content of essential amino acids and the in vitro N (85 %) and organic matter (90 %) digestibility, the extracted fraction seems a promising protein source in diets for monogastric animals with improved characteristics as compared to the intactU. lactuca. The gas production test indicated a moderate rumen fermentation ofU. lactucaand the extracted fraction, about similar to that of alfalfa. Reduction of the high content of minerals and trace elements may be required to allow a high inclusion level ofU. lactucaproducts in animal diets. The hydrolysate was used successfully for the production of acetone, butanol, ethanol and 1,2-propanediol by clostridial fermentation, and the rhamnose fermentation pattern was studied.
authors.affiliation: Livestock Research, Wageningen University and Research Centre, De Elst 1, 6708 WD Wageningen, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Bikker
authors.affiliation: Livestock Research, Wageningen University and Research Centre, De Elst 1, 6708 WD Wageningen, The Netherlands.
authors.forename: Marinus M
authors.initials: MM
authors.lastname: van Krimpen
authors.affiliation: Livestock Research, Wageningen University and Research Centre, De Elst 1, 6708 WD Wageningen, The Netherlands.
authors.forename: Piet
authors.initials: P
authors.lastname: van Wikselaar
authors.affiliation: Food and Biobased Research, Wageningen University and Research Centre, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
authors.forename: Bwee
authors.initials: B
authors.lastname: Houweling-Tan
authors.affiliation: Food and Biobased Research, Wageningen University and Research Centre, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
authors.forename: Nazareno
authors.initials: N
authors.lastname: Scaccia
authors.affiliation: Biomass & Energy Efficiency, Energy research Centre of the Netherlands (ECN), Westerduinweg 3, 1755 LE Petten, The Netherlands.
authors.forename: Jaap W
authors.initials: JW
authors.lastname: van Hal
authors.affiliation: Biomass & Energy Efficiency, Energy research Centre of the Netherlands (ECN), Westerduinweg 3, 1755 LE Petten, The Netherlands.
authors.forename: Wouter J J
authors.initials: WJ
authors.lastname: Huijgen
authors.affiliation: Animal Nutrition Group, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.
authors.forename: John W
authors.initials: JW
authors.lastname: Cone
authors.affiliation: Food and Biobased Research, Wageningen University and Research Centre, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
authors.forename: Ana M
authors.initials: AM
authors.lastname: López-Contreras
keywords: ABE fermentation; Animal feed; Biobutanol; Cascading biorefinery; In vitro digestibility; Seaweed; Ulva lactuca