Abiru, Makoto

Kyoto University Research Information Repository

Title Exposure of polysaccharides in lignocellulosics with peroxyacids produced by enzymatic perhydrolysisAuthor(s)Abiru, MakotoCitationSustainable humanosphere : bulletin of Research Institute forSustainable Humanosphere Kyoto University (2010), 6: 26-26Issue Date2010-09-10URL http://hdl.handle.net/2433/182506RightType Departmental Bulletin PaperTextversionpublisherKyoto UniversityABSTRACTS(MASTER THESIS)Exposure of polysaccharides in lignocellulosics with peroxy acids produced by                          enzymatic perhydrolysis              (Graduate School of Agriculture,Laboratory ofBiomass Conversion , RISH, Kyoto University)Makoto Abiru    In enzymatic saccharification of lignocellulosics, access of enzymes to exposed cellulose surfaces isan initial key step in triggering the hydrolysis. Peroxy acids are potential agents to degrade plant cell wallcomponents to expose cellulose. In this study the author focused on enzymatic production ofperoxy acids,and evaluated their reactivity to expose cellulose surfaces in lignocellulosic biomass. For the production ofperoxy acids, perhydrolysis of fatty acids by lipase was applied. Exposure ofthe polysaccharide by peroxyacids was analyzed using green fluorescent protein (GFP)-labeled carbohydrate-binding modules (CBMs)from Clostridium josui. As a specific markers for crystalline and non-crystalline cellulose, Cl'CBM3 andCl'CBM28 were used, respectively. Distribution of the exposed cellulose surfaces after reaction wasanalyzed using confocal laser scanning fluorescence microscope.    Japanese cedar wood was partially delignified by glycerolysis at 2000C for 6 min using microwaveirradiator. Insoluble pulp fraction was separated, washed successively with acetone and water, and used forthe analysis of the exposed cellulose. Peroxy acids were prepared by the reactions of lipase fromPenicillium camemberti with octanoic acid and H202 in chloroform. m-Chloroperbenzoic acid (mCPBA)was used as a standard compound ofperoxyacid.    The partially delignified pulp was treated with peroxyoctanoic acid, and adsorption of Cl'CBM28-GFPand Cl'CBM3-GFP on the substrate was analyzed before and after reaction. Adsorption of these probemolecule to crystalline and non-crystalline cellulose increased depending on the conditions for thepretreatment. Increase in the adsorption of fluorescent CBMs were also found in the treatments withmCPBA. Analysis with confocal laser fluorescence microscope showed that the lignocellulosics treatedwith peroxy acid was extensively fibered (Figure 1).    Peroxy acids formed by enzymatic perhydrolysis are the potential agent to expose cellulose surfaces inlignocellulosics. This expands roles of lipase and other lipid-related (per)hydrolytic enzymes from thedegradation of lipids to the exposure of cellulose surfaces, thereby accelerating microbial and enzymaticdegradation oflignified plant cell walls.Figure 1 Confocal laser fluorescence microscopic photographs ocedar wood after adsorption of Cl'CBM28-GFP.(a) untreated, (b) treated with peroxyoctanoic acidf partially delignifie d pulp from Japanese26

Exposure of polysaccharides in lignocellulosics with peroxy acids produced by enzymatic perhydrolysis

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Exposure of polysaccharides in lignocellulosics with peroxy acids produced by enzymatic perhydrolysis

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