Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside, California 92521, USA.
Biotechnol Bioeng. 2013 Mar;110(3):754-62. doi: 10.1002/bit.24751. Epub 2012 Nov 1.
Because conventional approaches for evaluating sugar release from the coupled operations of pretreatment and enzymatic hydrolysis are extremely time and material intensive, high throughput (HT) pretreatment and enzymatic hydrolysis systems have become vital for screening large numbers of lignocellulosic biomass samples to identify feedstocks and/or processing conditions that significantly improve performance and lower costs. Because dilute acid pretreatment offers many important advantages in rendering biomass highly susceptible to subsequent enzymatic hydrolysis, a high throughput pretreatment and co-hydrolysis (HTPH) approach was extended to employ dilute acid as a tool to screen for enhanced performance. First, a single-step neutralization and buffering method was developed to allow effective enzymatic hydrolysis of the whole pretreated slurry. Switchgrass and poplar were then pretreated with 0.5% and 1% acid loadings at a 5% solids concentration, the resulting slurry conditioned with the buffering approach, and the entire mixture enzymatically hydrolyzed. The resulting sugar yields demonstrated that single-step neutralizing and buffering was capable of adjusting the pH as needed for enzymatic saccharification, as well as overcoming enzyme inhibition by compounds released in pretreatment. In addition, the effects of pretreatment conditions and biomass types on susceptibility of pretreated substrates to enzymatic conversion were clearly discernible, demonstrating the method to be a useful extension of HTPH systems.
由于评估预处理和酶解偶联操作中糖释放的传统方法极其耗费时间和材料，高通量（HT）预处理和酶解系统已成为筛选大量木质纤维素生物质样品以识别可显著提高性能和降低成本的原料和/或加工条件的重要手段。由于稀酸预处理在使生物质高度易受后续酶解影响方面具有许多重要优势，因此扩展了高通量预处理和共水解（HTPH）方法，以利用稀酸作为筛选增强性能的工具。首先，开发了一种单步中和缓冲方法，以允许整个预处理浆料进行有效的酶水解。然后，用 0.5%和 1%的酸负荷在 5%的固体浓度下对柳枝稷和杨木进行预处理，用缓冲方法对所得浆料进行调理，然后对整个混合物进行酶水解。所得糖产量表明，单步中和缓冲能够根据酶糖化的需要调节 pH 值，并克服预处理中释放的化合物对酶的抑制作用。此外，预处理条件和生物质类型对预处理底物对酶转化的易感性的影响也明显不同，这表明该方法是 HTPH 系统的一个有用扩展。
