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عنوان فارسی مقاله:
به سمت تفکیک آنزیمی ساختار گیاه پیچیده زیلان: حالت هنر
عنوان انگلیسی مقاله:
Towards enzymatic breakdown of complex plant xylan structures: State of the art
سال انتشار : 2016
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مقدمه انگلیسی مقاله:
1. Introduction
The increasing worldwide effort to develop economically feasible and environmentally friendly procedures for bioconversion of plant biomass involves also the fraction of hemicellulose polysaccharides that are separated from cellulose and lignin during various pretreatments. The major plant hemicellulose of interest is xylan, a branched plant polysaccharide, characteristic feature of which is the backbone built of β-1,4- linked D-xylopyranosyl (Xylp) residues. Its fine structure changes from plant to plant, and even in different parts of the same plant (Ebringerová et al., 2005). Recent data indicates that differences in structure occur even within the same xylan molecule (Busse-Wicher et al., 2014). The variations are due to different side carbohydrate and acid substituents. With the exception of softwood xylan, in all other plants xylans are partially acetylated and in some cases also esterified with phenolic acids. Alkaline pretreatments afford deacetylated polysaccharide, e.g. glucuronoxylan from hardwood, arabinoxylan from cereal endosperm and arabinoglucuronoxylan from agricultural side products, such as straw and bran, and different maize residues. Milder alkaline pretreatments preserve ester linkages between Araf side substituents and phenolic acids, mainly ferulic acid (Schendel et al., 2015). Non-alkaline pretreatments, such as steam explosion and autohydrolysis, yield partially acetylated hemicellulose (Alvira et al., 2010; Appeldoorn et al., 2013; Selig et al., 2008; Wyman et al., 2005). Over the past two decades a great progress in enzymology of plant xylan degradation and saccharification has been achieved. New types of depolymerizing xylanases and debranching enzymes have been described in microorganisms and the structure-function relationship of accessory xylanolytic enzymes has become better understood. However, since the available data are scattered over the vast amount of published literature, and some xylan structures were recognized as recalcitrant to known enzymes only recently, we feel that it is of extreme importance to summarize current knowledge on microbial xylanolytic enzymes and outline possible strategies of enzymatic xylan degradation to oligosaccharides and also towards monosaccharide building blocks. The target sugar is naturally xylose which can serve as a source for production of a number of compounds including ethanol (Dodd and Cann, 2009; Gírio et al., 2010). As an added value to the previous reviews on this subject (Aachary and Prapulla, 2009; Beg et al., 2001; Deutschmann and Dekker, 2012; Keshwani and Cheng, 2009; Polizeli et al., 2005; Saha, 2003; Shallom and Shoham, 2003; Van den Brink and de Vries, 2011; Van Dyk and Pletschke, 2012), we distinguish here between xylans that were extracted from plant biomass in the presence of alkali which destroys almost all ester linkages, and xylans obtained under non-alkaline conditions which preserve considerable portion of ester linkages, and afford partially esteri- fied polysaccharide that corresponds to its native form in plants. In all cases the enzymatic hydrolysis of xylan passes the stage of oligosaccharides which can also be considered as desired products. They find applications as prebiotics, dietary fibers and antioxidants (Broekaert et al., 2011).
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کلمات کلیدی:
Towards enzymatic breakdown of complex plant xylan structures https://www.researchgate.net/.../308092977_Towards_enzymatic_breakdown_of_compl... Dec 1, 2016 - Contact 2 of the authors on ResearchGate · Towards enzymatic breakdown of complex plant xylan structures: State of the art. Towards enzymatic breakdown of complex plant xylan structures ... https://www.linkedin.com/.../towards-enzymatic-breakdown-complex-plant-xylan-stat... Sep 14, 2016 - progress over the past few years has been achieved in the enzymology of microbial degradation and saccharification of plant xylan, after ... [PDF]Chapter 2 Chemical Composition and Structure of - Springer www.springer.com/cda/content/document/cda.../9789400768970-c2.pdf?SGWID... Abstract The wide variety of natural cellulosic materials has complex and uneven components. ... a raw material for research on the structure of cellulose in plant cell walls. Cotton ...... 2.4.1.1 Chemical Structure of Xylan Hemicelluloses. Industrial Enzymes: Structure, Function and Applications https://books.google.com/books?isbn=1402053770 Julio Polaina, Andrew P. MacCabe - 2007 - Science Structure, Function and Applications Julio Polaina, Andrew P. MacCabe ... Xylan is a complex polysaccharide composed of a backbone of -1,4-linked xylopyranosyl ... depending on the plant source, can be variably substituted by side chains of ... Due its heterogeneity and complex nature, the complete breakdown of xylan ... Characterization of Oligomeric Xylan Structures ... - ACS Publications pubs.acs.org/doi/abs/10.1021/jf102849x by MM Appeldoorn - 2010 - Cited by 58 - Related articles Oct 13, 2010 - Structural knowledge of the hemicellulose is needed to improve the ... Towards enzymatic breakdown of complex plant xylan structures: State of ... Bioprocessing Technologies in Biorefinery for Sustainable Production ... https://books.google.com/books?isbn=1118641949 Shang-Tian Yang, Hesham El-Ensashy, Nuttha Thongchul - 2013 - Technology & Engineering ... cleave the B-1,4 backbone of the complex plant cell wall polysaccharide xylan. ... 9.2.1 Chemical Structure of Xylan Plant biomass comprises on average 23% ... Characterization of Oligomeric Xylan Structures ... - ACS Publications pubs.acs.org/doi/full/10.1021/jf102849x by MM Appeldoorn - 2010 - Cited by 58 - Related articles Oct 13, 2010 - The data show that complex xylan oligomers are present in which ferulic acid, ... Corn fibers from a dry fractionation plant were milled, using a Retsch ZM200 ..... Sugar Composition and Distribution of the 12 Enzyme-Resistant ...
