Abstract Enzymatic hydrolysis of biomass is an established method for producing biofuels. Lignocellulosic biomass such as corn stover is very inhomogeneous material with big variation on conversion rates between individual particles therefore leading to variable recalcitrance results. In this study, we used noninvasive optical microscopy techniques, such as two‐photon microscopy and fluorescence lifetime imaging microscopy, to visualize and analyze morphological and chemical changes of individual corn stover particles pretreated with sulfuric acid during hydrolysis. Morphochemical changes were interpreted based on the fluorescence properties of isolated building blocks of plant cell wall, such as cellulose, hemicellulose, and lignin. Enzymatic hydrolysis resulted in particle size reduction, side wall collapse, decrease of second harmonic signal from cellulose, redshifting of autofluorescence emission, and lifetime decrease attributed to the relative increase of lignin. Based on these observations, tracking compositional change after hydrolysis of individual particles was accomplished. The methodologies developed offer a paradigm for imaging and analyzing enzymatic hydrolysis in vitro and in situ, which could be used for screening enzymes cocktails targeting specific recalcitrant structures or investigating locally enzyme anti‐inhibitory agents.

中文翻译：

---

基于自发荧光成像对单个生物质颗粒原位酶水解过程中的形态化学变化进行定量

摘要 生物质的酶水解是生产生物燃料的既定方法。木质纤维素生物质（例如玉米秸秆）是非常不均匀的材料，各个颗粒之间的转化率变化很大，因此导致不同的不顺应结果。在这项研究中，我们使用非侵入性光学显微镜技术，例如双光子显微镜和荧光寿命成像显微镜，来可视化和分析水解过程中用硫酸预处理的单个玉米秸秆颗粒的形态和化学变化。根据植物细胞壁的孤立构件（例如纤维素、半纤维素和木质素）的荧光特性来解释形态化学变化。酶水解导致颗粒尺寸减小、侧壁塌陷、纤维素二次谐波信号减少、自发荧光发射红移以及由于木质素相对增加而导致的寿命缩短。基于这些观察，完成了对单个颗粒水解后成分变化的追踪。开发的方法为体外和原位酶水解成像和分析提供了范例，可用于筛选针对特定顽固结构的酶混合物或研究局部酶抗抑制剂。