Unlocking the potential of lignocellulosic biomass through plant science

Abstract

Summary: The aim of producing sustainable liquid biofuels and chemicals from lignocellulosic biomass remains high on the sustainability agenda, but is challenged by the costs of producing fermentable sugars from these materials. Sugars from plant biomass can be fermented to alcohols or even alkanes, creating a liquid fuel in which carbon released on combustion is balanced by its photosynthetic capture. Large amounts of sugar are present in the woody, nonfood parts of crops and could be used for fuel production without compromising global food security. However, the sugar in woody biomass is locked up in the complex and recalcitrant lignocellulosic plant cell wall, making it difficult and expensive to extract. In this paper, we review what is known about the major polymeric components of woody plant biomass, with an emphasis on the molecular interactions that contribute to its recalcitrance to enzymatic digestion. In addition, we review the extensive research that has been carried out in order to understand and reduce lignocellulose recalcitrance and enable more cost‐effective production of fuel from woody plant biomass. Contents Summary 1366 I. Introduction 1366 II. Lignocellulosic feedstocks 1367 III. Measuring cell wall recalcitrance 1368 IV. Cellulose 1368 V. Hemicellulose 1369 VI. Side‐chain substitution of xylans 1370 VII. Pectin 1372 VIII. Lignin 1372 IX. Ferulic acid linkages 1376 X. Final considerations 1377 Acknowledgements 1377 References 1377