Novozymes, Inc., 1445 Drew Avenue, Davis, CA 95618, United States.
Enzyme Microb Technol. 2011 Mar 7;48(3):239-47. doi: 10.1016/j.enzmictec.2010.11.004. Epub 2010 Nov 18.
Phenolics derived from lignin and other plant components can pose significant inhibition on enzymatic conversion of cellulosic biomass materials to useful chemicals. Understanding the mechanism of such inhibition is of importance for the development of viable biomass conversion technologies. In native plant cell wall, most of the phenolics and derivatives are found in polymeric lignin. When biomass feedstocks are pretreated (prior to enzymatic hydrolysis), simple or oligomeric phenolics and derivatives are often generated from lignin modification/degradation, which can inhibit biomass-converting enzymes. To further understand how such phenolic substances may affect cellulase reaction, we carried out a comparative study on a series of simple and oligomeric phenolics representing or mimicking the composition of lignin or its degradation products. Consistent to previous studies, we observed that oligomeric phenolics could exert more inhibition on enzymatic cellulolysis than simple phenolics. Oligomeric phenolics could inactivate cellulases by reversibly complexing them. Simple and oligomeric phenolics could also inhibit enzymatic cellulolysis by adsorbing onto cellulose. Individual cellulases showed different susceptibility toward these inhibitions. Polyethylene glycol and tannase could respectively bind and degrade the studied oligomeric phenolics, and by doing so mitigate the oligomeric phenolic's inhibition on cellulolysis.
木质素和其他植物成分衍生的酚类物质会对纤维素生物质材料转化为有用化学品的酶促转化产生显著抑制。了解这种抑制的机制对于开发可行的生物质转化技术非常重要。在天然植物细胞壁中，大多数酚类物质和衍生物存在于聚合木质素中。当生物质原料进行预处理（在酶解之前）时，木质素的修饰/降解通常会产生简单或低聚酚类物质和衍生物，从而抑制生物质转化酶。为了进一步了解这些酚类物质如何影响纤维素酶反应，我们对一系列简单和低聚酚类物质进行了比较研究，这些物质代表或模拟木质素或其降解产物的组成。与先前的研究一致，我们观察到低聚酚类物质对酶促纤维素分解的抑制作用强于简单酚类物质。低聚酚类物质可以通过可逆地与纤维素酶结合而使纤维素酶失活。简单和低聚酚类物质也可以通过吸附到纤维素上来抑制纤维素酶的酶促纤维素分解。个别纤维素酶对这些抑制作用的敏感性不同。聚乙二醇和单宁酶可以分别结合和降解研究中使用的低聚酚类物质，并通过这种方式减轻低聚酚类物质对纤维素分解的抑制作用。
