Biomass Conversion Research Laboratory, Chemical Engineering and Materials Science, Michigan State University, Lansing, MI 48824, USA; DOE-Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, East Lansing, MI 48824, USA.
DOE-Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA.
Bioresour Technol. 2014;152:38-45. doi: 10.1016/j.biortech.2013.10.082. Epub 2013 Nov 1.
Sequential fractionation of AFEX-pretreated corn stover extracts was carried out using ultra-centrifugation, ultra-filtration, and solid phase extraction to isolate various classes of pretreatment products to evaluate their inhibitory effect on cellulases. Ultra-centrifugation removed dark brown precipitates that caused no appreciable enzyme inhibition. Ultra-filtration of ultra-centrifuged AFEX-pretreated corn stover extractives using a 10 kDa molecular weight cutoff (MWCO) membrane removed additional high molecular weight components that accounted for 24-28% of the total observed enzyme inhibition while a 3 kDa MWCO membrane removed 60-65%, suggesting significant inhibition is caused by oligomeric materials. Solid phase extraction (SPE) of AFEX-pretreated corn stover extractives after ultra-centrifugation removed 34-43% of the inhibition; ultra-filtration with a 5 kDa membrane removed 44-56% of the inhibition and when this ultra-filtrate was subjected to SPE a total of 69-70% of the inhibition were removed. Mass spectrometry found several phenolic compounds among the hydrophobic inhibition removed by SPE adsorption.
采用超离心、超滤和固相萃取对 AFEX 预处理玉米秸秆提取物进行顺序分段，以分离各种预处理产物类别，评估它们对纤维素酶的抑制作用。超离心去除了深褐色沉淀，这些沉淀不会导致明显的酶抑制。使用 10 kDa 分子量截止值（MWCO）膜对超离心后的 AFEX 预处理玉米秸秆提取物进行超滤，去除了额外的高分子量成分，这些成分占总观察到的酶抑制的 24-28%，而 3 kDa MWCO 膜去除了 60-65%，表明低聚材料是主要的抑制因素。超离心后的 AFEX 预处理玉米秸秆提取物经固相萃取（SPE）去除了 34-43%的抑制物；使用 5 kDa 膜超滤去除了 44-56%的抑制物，当将这种超滤物进行 SPE 时，总共去除了 69-70%的抑制物。质谱分析发现，通过 SPE 吸附去除的疏水性抑制物中存在几种酚类化合物。
Zotero 插件