Cheryl & ethnovet: Biorefinery of the green seaweed Ulva lactuca to produce animal feed, chemicals and biofuels.

Tuesday, 13 June 2017

Biorefinery of the green seaweed Ulva lactuca to produce animal feed, chemicals and biofuels.

2016;28(6):3511-3525. doi: 10.1007/s10811-016-0842-3. Epub 2016 Apr 23.

Bikker P¹, van Krimpen MM¹, van Wikselaar P¹, Houweling-Tan B², Scaccia N², van Hal JW³, Huijgen WJ³, Cone JW⁴, López-Contreras AM².

Author information

1: Livestock Research, Wageningen University and Research Centre, De Elst 1, 6708 WD Wageningen, The Netherlands.
2: Food and Biobased Research, Wageningen University and Research Centre, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
3: Biomass & Energy Efficiency, Energy research Centre of the Netherlands (ECN), Westerduinweg 3, 1755 LE Petten, The Netherlands.
4: Animal Nutrition Group, Wageningen University, De Elst 1, 6708 WD Wageningen, The Netherlands.

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 seaweed Ulva lactuca containing 225 g protein (N × 4.6) kg^-1 dry 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^-1 sugars) containing glucose, rhamnose and xylose, and a protein-enriched (343 g kg^-1 in DM) extracted fraction. This extracted fraction was characterised for use in animal feed, as compared to U. lactuca biomass. 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 intact U. lactuca. The gas production test indicated a moderate rumen fermentation of U. lactuca and 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 of U. lactuca products 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.