Laboratory of Plant Breeding, Wageningen University & Research, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands.
Wageningen Food and Biobased Research, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
Molecules. 2021 Jan 6;26(2):254. doi: 10.3390/molecules26020254.
Lignocellulosic crops are attractive bioresources for energy and chemicals production within a sustainable, carbon circular society. Miscanthus is one of the perennial grasses that exhibits great potential as a dedicated feedstock for conversion to biobased products in integrated biorefineries. The current biorefinery strategies are primarily focused on polysaccharide valorization and require severe pretreatments to overcome the lignin barrier. The need for such pretreatments represents an economic burden and impacts the overall sustainability of the biorefinery. Hence, increasing its efficiency has been a topic of great interest. Inversely, though pretreatment will remain an essential step, there is room to reduce its severity by optimizing the biomass composition rendering it more exploitable. Extensive studies have examined the miscanthus cell wall structures in great detail, and pinpointed those components that affect biomass digestibility under various pretreatments. Although lignin content has been identified as the most important factor limiting cell wall deconstruction, the effect of polysaccharides and interaction between the different constituents play an important role as well. The natural variation that is available within different miscanthus species and increased understanding of biosynthetic cell wall pathways have specified the potential to create novel accessions with improved digestibility through breeding or genetic modification. This review discusses the contribution of the main cell wall components on biomass degradation in relation to hydrothermal, dilute acid and alkaline pretreatments. Furthermore, traits worth advancing through breeding will be discussed in light of past, present and future breeding efforts.
木质纤维素作物是在可持续的碳循环社会中生产能源和化学品的有吸引力的生物资源。芒草是多年生草本植物之一，作为一种专门的原料，具有很大的潜力，可在综合生物精炼厂中转化为生物基产品。目前的生物精炼策略主要集中在多糖的增值利用上，需要进行苛刻的预处理，以克服木质素障碍。这种预处理的需求代表了经济负担，并影响了生物精炼厂的整体可持续性。因此，提高其效率一直是一个非常关注的话题。相反，尽管预处理仍将是一个必不可少的步骤，但通过优化生物质的组成，可以降低其苛刻程度，使其更具可利用性。大量研究详细研究了芒草细胞壁结构，并确定了在各种预处理条件下影响生物质可消化性的那些成分。尽管木质素含量已被确定为限制细胞壁解构的最重要因素，但多糖的作用和不同成分之间的相互作用也起着重要作用。不同芒草种内的自然变异以及对生物合成细胞壁途径的深入了解，为通过育种或遗传修饰创造具有改善消化率的新型品系提供了潜力。本文综述了主要细胞壁成分在与水热、稀酸和碱性预处理相关的生物质降解中的作用。此外，还将根据过去、现在和未来的育种工作，讨论通过育种值得改进的特性。
