Abstract
Converting biomass to biofuels is a key strategy in substituting fossil fuels to mitigate climate change. Conventional strategies to convert lignocellulosic biomass to ethanol address the fermentation of cellulose-derived glucose. Here we used super-resolution fluorescence microscopy to uncover the nanoscale structure of cell walls in the energy crops maize and Miscanthus where the typical polymer cellulose forms an unconventional layered architecture with the atypical (1, 3)-β-glucan polymer callose. This raised the question about an unused potential of (1, 3)-β-glucan in the fermentation of lignocellulosic biomass. Engineering biomass conversion for optimized (1, 3)-β-glucan utilization, we increased the ethanol yield from both energy crops. The generation of transgenic Miscanthus lines with an elevated (1, 3)-β-glucan content further increased ethanol yield providing a new strategy in energy crop breeding. Applying the (1, 3)-β-glucan-optimized conversion method on marine biomass from brown macroalgae with a naturally high (1, 3)-β-glucan content, we not only substantially increased ethanol yield but also demonstrated an effective co-fermentation of plant and marine biomass. This opens new perspectives in combining different kinds of feedstock for sustainable and efficient biofuel production, especially in coastal regions.
Highlights
Converting biomass to biofuels is a key strategy in substituting fossil fuels to mitigate climate change
An increasing worldwide demand for energy combined with decreasing fossil energy resources fosters climate change[1] and explorations for fossil energy in sensitive ecosystems[2]
Because liquid fuels play a predominant role in the transportation sector, second generation biofuels from lignocellulosic feedstock reveal a high potential in substituting fossil fuels[3]
Summary
Subsequent procedures of (1, 3)-β-glucan determination followed the description in Voigt et al.[27]. Standards ranging from 0 to 20 μ g ml−1 were generated from purified (1, 3)-β-glucan from Euglena gracilis (Sigma-Aldrich, Germany) in the same way as described for plant and alga samples. Additional standards were generated from oat and barley (1, 3;1, 4)-β-glucan deriving from the mixed-linkage beta-glucan kit (Megazyme, Ireland) to verify the specificity of ABF in staining. Mixed linkage (1, 3;1, 4)-β-glucan in plant biomass was determined according to the manufacturer’s description of the mixed-linkage beta-glucan kit (Megazyme). The green fluorescence protein (GFP)-tagged (1, 3)-β-glucan synthase PMR4 and single GFP in leaves of transformed Miscanthus lines was localized by CLSM. The generation of transgenic Miscanthus lines followed the principal procedure of Agrobacterium-mediated callus transformation and selection on hygromycin-containing plant cell culture medium.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
