Innovative approaches for sustainable bio-based products
This report is by Ana Cristina Oliveira from LNEG. It is research work developed under Task 7.3.
Miscanthus sp. is an abundant and inexpensive feedstock in Europe that can be used as carbon source in media formulation for microbial conversion and the production of added-value compounds. As low-cost substrate, Miscanthus biomass may also contribute to reduce the overall bioconversion process costs.
LNEG developed a biorefinery platform based in anaerobic and aerobic fermentation of Miscanthus biomass. The conversion processes and targeted bioproducts are depicted in Fig.1, below.
- Hydrothermal pretreatment followed by enzymatic hydrolysis of Miscanthus biomass enabled the production of a fermentable hydrolysate, containing glucose as the predominant monosaccharide and a minor amount of xylose. The conversion of the sugars in the hydrolysate by C. butyricum originated butyrate as major fermentation metabolite and acetate, so as a H2-rich biogas stream. The results obtained show the potential of Miscanthus as biomass crop for biochemical conversion into hydrogen as bioenergy vector, and butyrate and acetate as platform chemicals.
- The yeast R. toruloides grown on Miscanthus sp. hydrolysate diluted at the ratio of 1:3 produced a lipid content of 30 % (w/w DCW), with a fatty acid composition suitable for biodiesel purposes. Therefore, the process here proposed for biodiesel production may have potential at a commercial scale. The results also demonstrated that the developed flow cytometric method, coupled with the double staining TO/PI protocol, is a valuable at-line tool to monitor R. toruloides cell stress response, during growth on Miscanthus sp. hydrolysate.
ANAEROBIC Fermentation: Patrícia Moura & Joana Ortigueira;
AEROBIC Fermentation: Teresa Lopes da Silva & Joana Martins
ENZYMATIC HYDROLYSIS: Susana Marques
HYDROTHERMAL: Florbela Carvalheiro & Diogo Vicente