Authors: Jin Gu Jeffrey M Catchmark
Publish Date: 2013/11/26
Volume: 21, Issue: 1, Pages: 275-289
Abstract
Xyloglucan and pectin are major noncellulosic components of most primary plant cell walls It is believed that xyloglucan and perhaps pectin are functioning as tethers between cellulose microfibrils in the cell walls In order to understand the role of xyloglucan and pectin in cell wall mechanical properties model cell wall composites created using Gluconacetobacter xylinus cellulose or cellulose nanowhiskers CNWs derived there from with different amounts of xyloglucan and/or pectin have been prepared and measured under extension conditions Compared with pure CNW films CNW composites with lower amounts of xyloglucan or pectin did not show significant differences in mechanical behavior Only when the additives were as high as 60 the films exhibited a slightly lower Young’s modulus However when cultured with xyloglucan or pectin the bacterial cellulose BC composites produced by G xylinus showed much lower modulus compared with that of the pure BC films Xyloglucan was able to further reduce the modulus and extensibility of the film compared to that of pectin It is proposed that surface coating or tethering of xyloglucan or pectin of cellulose microfibrils does not alone affect the mechanical properties of cell wall materials The implication from this work is that xyloglucan or pectin alters the mechanical properties of cellulose networks during rather than after the cellulose biosynthesis process which impacts the nature of the connection between these compoundsThis research was supported as part of The Center for LignoCellulose Structure and Formation an Energy Frontier Research Center funded by the US Department of Energy Office of Science under Award Number DESC0001090 SEM and XRD were supported by the Pennsylvania State University Materials Research Institute Nanofabrication Lab and the National Science Foundation Cooperative Agreement No ECS0335765 The authors thank Lin Fang from PSU for some sample preparations and useful discussion
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