Highly efficient breaking lignocellulose cell wall recalcitrance towards biomass valorization still remains a great challenge. In this work, we developed a very effective lignin-first strategy using diols for direct fractionation of light-color lignin, and resulting in enhancement of enzymatic saccharification of cellulose-rich residues. The isolated lignin fraction possessed relatively higher content of β-O-4 linkages (26.6%), purity (>99%) and yield (>50%) and its brightness reached 22.0%ISO, which was 15.3, 13.5 and 1.9 folds higher than Kraft lignin, lignosulfonate and alkali lignin, respectively. In addition, the obtained nearly white-color lignin could be efficiently and directionally depolymerized into syringyl type phenols with high yields (82.0% of total phenols). Enzymatic hydrolysis efficiency of cellulose-rich residues was significantly enhanced up to 84.95% due to the more effective adsorption of cellulase under this diols strategy. Overall, the developed lignin-first strategy showed noteworthy preponderance on overcoming cell wall recalcitrance to achieve the whole lignocellulosic components valorization.

高效打破木质纤维素细胞壁对生物质增值的顽固仍然是一个巨大的挑战。在这项工作中，我们开发了一种非常有效的木质素优先策略，使用二醇直接分馏浅色木质素，从而增强酶促糖化富含纤维素的残留物。分离出的木质素部分具有较高的β-O-4键含量（26.6%）、纯度（>99%）和收率（>50%），其亮度达到22.0%ISO，分别高出15.3、13.5和1.9倍分别优于牛皮纸木质素、木质素磺酸盐和碱木质素。此外，获得的近乎白色的木质素可以高效、定向解聚成紫丁香基型酚，收率高（占总酚的 82.0%）。由于在这种二醇策略下纤维素酶的更有效吸附，富含纤维素的残留物的酶水解效率显着提高至 84.95% 。总体而言，开发的木质素优先策略在克服细胞壁顽固性以实现整个木质纤维素成分的价值化方面表现出显着的优势。