Voiland School of Chemical Engineering and Bioengineering, Bioproducts, Science and Engineering Laboratory, Washington State University, Richland, WA, 99354, USA.
Appl Microbiol Biotechnol. 2014 May;98(10):4409-20. doi: 10.1007/s00253-013-5450-4. Epub 2013 Dec 14.
Three commercial cellulase preparations, Novozymes Cellic(®) Ctec2, Dupont Accellerase(®) 1500, and DSM Cytolase CL, were evaluated for their hydrolytic activity using a set of reference biomass substrates with controlled substrate characteristics. It was found that lignin remains a significant recalcitrance factor to all the preparations, although different enzyme preparations respond to the inhibitory effect of lignin differently. Also, different types of biomass lignin can inhibit cellulase enzymes in different manners. Enhancing enzyme activity toward biomass fiber swelling is an area significantly contributing to potential improvement in cellulase performance. While the degree of polymerization of cellulose in the reference substrates did not present a major recalcitrance factor to Novozymes Cellic(®) Ctec2, cellulose crystallite has been shown to have a significant lower reactivity toward all enzyme mixtures. The presence of polysaccharide monooxygenases (PMOs) in Novozymes Ctec2 appears to enhance enzyme activity toward decrystallization of cellulose. This study demonstrated that reference substrates with controlled chemical and physical characteristics of structural features can be applied as an effective and practical strategy to identify cellulosic enzyme activities toward specific biomass recalcitrance factor(s) and provide specific targets for enzyme improvement.
三种商业纤维素酶制剂，诺维信 Cellic(®) Ctec2、杜邦 Accellerase(®) 1500 和 DSM Cytolase CL，使用一组具有受控底物特性的参考生物质底物来评估其水解活性。结果发现，尽管不同的酶制剂对木质素的抑制作用有不同的反应，但木质素仍然是所有制剂的一个重要的抗性因素。此外，不同类型的生物质木质素可以以不同的方式抑制纤维素酶。提高酶对生物质纤维膨胀的活性是显著提高纤维素酶性能的一个重要领域。虽然参考底物中纤维素的聚合度对诺维信 Cellic(®) Ctec2 来说不是一个主要的抗性因素，但纤维素微晶已被证明对所有酶混合物的反应性显著降低。Novozymes Ctec2 中存在多糖单加氧酶 (PMO) 似乎可以提高酶对纤维素去结晶的活性。本研究表明，具有结构特征的受控化学和物理特性的参考底物可以作为一种有效和实用的策略，用于鉴定纤维素酶对特定生物质抗性因素的活性，并为酶的改进提供特定的目标。
