Effects of plant cell wall matrix polysaccharides on bacterial cellulose structure studied with vibrational sum frequency generation spectroscopy and X-ray diffraction.
The crystallinity, allomorph content, and mesoscale ordering of cellulose produced by Gluconacetobacter xylinus cultured with different plant cell wall matrix polysaccharides were studied with vibrational sum frequency generation (SFG) spectroscopy and X-ray diffraction (XRD). Crystallinity and ordering were assessed as the intensity of SFG signals in the CH/CH2 stretch vibration region (and confirmed by XRD), while Iα content was assessed by the relative intensity of the OH stretch vibration at 3240 cm(-1). A key finding is that the presence of xyloglucan in the culture medium greatly reduced Iα allomorph content but with a relatively small effect on cellulose crystallinity, whereas xylan resulted in a larger decrease in crystallinity with a relatively small decrease in the Iα fraction. Arabinoxylan and various pectins had much weaker effects on cellulose structure as assessed by SFG and XRD. Homogalacturonan with calcium ion reduced the SFG signal, evidently by changing the ordering of cellulose microfibrils. We propose that the distinct effects of matrix polysaccharides on cellulose crystal structure result, at least in part, from selective interactions of the backbone and side chains of matrix polysaccharides with cellulose chains during the formation of the microfibril.
Department of Biology and ‡Department of Chemical Engineering and Materials Research Institute, Pennsylvania State University , University Park, Pennsylvania 16802, United States.
Yong Bum
YB
Park
Christopher M
CM
Lee
Kabindra
K
Kafle
Sunkyu
S
Park
Daniel J
DJ
Cosgrove
Seong H
SH
Kim
D002236:Carbohydrate Conformation; D002473:Cell Wall / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry* / Q000648:ultrastructure; D003460:Crystallization; D018360:Crystallography, X-Ray; D005936:Glucans / Q000737:chemistry; D041822:Gluconacetobacter xylinus / Q000737:chemistry; D010368:Pectins / Q000737:chemistry*; D059828:Plant Cells / Q000737:chemistry; D014732:Vibration; D014990:Xylans / Q000737:chemistry
D005936:Glucans; D014990:Xylans; C029353:xyloglucan; D010368:Pectins; D002482:Cellulose; C085118:arabinoxylan; C003181:polygalacturonic acid