20702-56-1Relevant articles and documents
Supercritical water treatment for cello-oligosaccharide production from microcrystalline cellulose
Tolonen, Lasse K.,Juvonen, Minna,Niemel?, Klaus,Mikkelson, Atte,Tenkanen, Maija,Sixta, Herbert
, p. 16 - 23 (2015)
Microcrystalline cellulose was treated in supercritical water at 380 °C and at a pressure of 250 bar for 0.2, 0.4, and 0.6 s. The yield of the ambient-water-insoluble precipitate and its average molar mass decreased with an extended treatment time. The highest yield of 42 wt % for DP2-9 cello-oligosaccharides was achieved after the 0.4 s treatment. The reaction products included also 11 wt % ambient-water-insoluble precipitate with a DPw of 16, and 6.1 wt % monomeric sugars, and 37 wt % unidentified degradation products. Oligo- and monosaccharide-derived dehydration and retro-aldol fragmentation products were analyzed via a combination of HPAEC-PAD-MS, ESI-MS/MS, and GC-MS techniques. The total amount of degradation products increased with treatment time, and fragmented (glucosyln-erythrose, glucosyln-glycolaldehyde), and dehydrated (glucosyln-levoglucosan) were identified as the main oligomeric degradation products from the cello-oligosaccharides.
Hydrolysis behaviors of sugarcane bagasse pith in subcritical carbon dioxide-water
Liang, Jiezhen,Chen, Xiaopeng,Wang, Linlin,Wei, Xiaojie,Qiu, Feifei,Lu, Chaochao
, p. 99322 - 99330 (2016/11/02)
The aim of this study was to describe the hydrolysis behavior of sugarcane bagasse pith (SCBP) in subcritical CO2-water. The hydrolysis was carried out in a batch reactor using different temperatures (160 to 260 °C), liquid to solid ratios (20:1 to 100:1), CO2 pressures (0 to 7.3 MPa), stirring speeds (0 to 500 rpm) and reaction times (0 to 40 min). The highest total reducing sugar yield (43.6%) was obtained at 200 °C, liquid to solid ratio 30:1, 2 MPa CO2, 500 rpm and 50 min. Two-dimensional heteronuclear single quantum coherence (2D HSQC) nuclear magnetic resonance (NMR), scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FT-IR) were used to help elucidate the physical and chemical characteristics of the raw material and residual solid particles, with results consistent with the removal of hemicellulose during hydrolysis. The changes in the concentration of products with time were analyzed to understand product distribution through high-performance liquid chromatography (HPLC) and to infer the reaction mechanism.
Structural and biochemical analyses of glycoside hydrolase families 5 and 26 β-(1,4)-mannanases from Podospora anserina reveal differences upon manno-oligosaccharide catalysis
Couturier, Marie,Roussel, Alain,Rosengren, Anna,Leone, Philippe,Stalbrand, Henrik,Berrin, Jean-Guy
, p. 14624 - 14635 (2013/07/28)
The microbial deconstruction of the plant cell wall is a key biological process that is of increasing importance with the development of a sustainable biofuel industry. The glycoside hydrolase families GH5 (PaMan5A) and GH26 (PaMan26A) endo-β-1,4-mannanases from the coprophilic ascomycete Podospora anserina contribute to the enzymatic degradation of lignocellulosic biomass. In this study, P. anserina mannanases were further subjected to detailed comparative analysis of their substrate specificities, active site organization, and transglycosylation capacity. Although PaMan5A displays a classical mode of action, PaMan26A revealed an atypical hydrolysis pattern with the release of mannotetraose and mannose from mannopentaose resulting from a predominant binding mode involving the -4 subsite. The crystal structures of PaMan5A and PaMan26A were solved at 1.4 and 2.85 A resolution, respectively. Analysis of the PaMan26A structure supported strong interaction with substrate at the -4 subsite mediated by two aromatic residues Trp-244 and Trp-245. The PaMan26A structure appended to its family 35 carbohydrate binding module revealed a short and proline-rich rigid linker that anchored together the catalytic and the binding modules.
