title: Two degradation strategies for overcoming the recalcitrance of natural lignocellulosic xylan by polysaccharides-binding GH10 and GH11 xylanases of filamentous fungi.
abstract: The recalcitrance of lignocellulose forms a strong barrier for the bioconversion of lignocellulosic biomass in chemical or biofuel industries. Filamentous fungi are major plant biomass decomposer, and capable of forming all the required enzymes. Here, they characterized the GH10 and GH11 endo-xylanases and a CE1 acetyl-xylan esterase (Axe1) from a superior biomass-degrading strain, Aspergillus fumigatus Z5, and examined how they interact in xylan degradation. Cellulose-binding (CBM1) domain inhibited GH10 xylanase activities for pure xylan, but afforded them an ability to hydrolyze washed corncob particles (WCCP). CBM1-containing GH10 xylanases also showed synergism with CBM1-containing Axe1 in WCCP hydrolysis, and this synergy was strictly dependent on the presence of their CBM1 domains. In contrast, GH11 xylanases had no CBM1, but still could bind xylan and hydrolyzed WCCP; however, no synergism displayed with Axe1. GH10 xylanases and GH11 xylanases showed a pronounced synergism in WCCP hydrolysis, which was dependent on the presence of the CBM1 in GH10 xylanases and absence from GH11 xylanases. They exhibit different mechanisms to bind to cellulose and xylan, and act in synergy when these two structures are intact. These findings will be helpful for the further development of highly efficient enzyme mixtures for lignocellulosic biomass conversion.
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Youzhi
authors.initials: Y
authors.lastname: Miao
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Pan
authors.initials: P
authors.lastname: Li
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Guangqi
authors.initials: G
authors.lastname: Li
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Dongyang
authors.initials: D
authors.lastname: Liu
authors.affiliation: Research Area Biochemical Technology, TU Wien, Gumpendorferstrasse 1a, Vienna, A1060, Austria.
authors.forename: Irina S
authors.initials: IS
authors.lastname: Druzhinina
authors.affiliation: Research Area Biochemical Technology, TU Wien, Gumpendorferstrasse 1a, Vienna, A1060, Austria.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Kubicek
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Jiangsu Key Lab and Engineering Center for Solid Organic Waste Utilization, National Engineering Research Center for Organic-based Fertilizers, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.|Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
authors.forename: Ruifu
authors.initials: R
authors.lastname: Zhang
mesh_terms: D018533:Biomass; D002482:Cellulose / Q000378:metabolism; D043364:Endo-1,4-beta Xylanases / Q000378:metabolism*; D005658:Fungi / Q000378:metabolism*; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D011134:Polysaccharides / Q000378:metabolism*; D014990:Xylans / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; D014990:Xylans; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D043364:Endo-1,4-beta Xylanases