Comparative characterization of ethanol organosolv lignin polymer from bamboo green, timber and yellow
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In order to make better use of bamboo resources in industrial processes, it is necessary to understand its recalcitrant morphological stem structure and unique chemical composition. In the present work, microspectroscopic imaging approaches were used to reveal the heterogeneous distribution of lignin at cellular and subcellular level. Results showed the higher lignin concentration in the narrow layer of fiber and parenchyma secondary cell walls. Furthermore, ethanol organosolv lignin, isolated from different zones of the bamboo vascular tissue [outer (green), middle (timber) and inner (yellow)], was subjected to extensive structural characterization, including chemical component analysis, Fourier-transform infrared spectroscopy (FT-IR), thermogravimetric/differential thermal analysis (TGA/DTA), and nuclear magnetic resonance (NMR). Main chemical differences among the green, timber and yellow zone were sugar content and S/G/H ratios. Since bamboo green had higher density, hardness and lignin content than bamboo timber and bamboo yellow, the mass transfer during the organosolv process was limited and resulted in the reduced removal/dissolution of polysaccharides at the same acidic conditions. Because bamboo green exhibited the highest content of G units in the vascular tissue, it was more condensed and thus had increased thermal stability compared to bamboo timber and bamboo yellow.
This paper is the result of collaboration between research teams at the International Centre for Bamboo and Rattan (ICBR). The work presented is supported by ICBR Fundamental Research Funds Grant (No. 1632016012) and the National Key Technology R&D Program of China during the 12th 5-year Plan Period (2015BAD04B03). We also gratefully acknowledge the contributions of Prof. Xiaomei Jiang, who gave me more suggestion for the cell structure. Research conducted in Professor Andrea Polle’s laboratory was supported by Georg-August University Göttingen and the Deutsche Forschungsgemeinschaft (DFG).
- Gierlinger N, Burgert I (2006) Secondary cell wall polymers studied by confocal Raman microscopy: spatial distribution, orientation, and molecular deformation. NZ J For Sci 1:60–71Google Scholar
- Jin KX, Cui HS, Liu XE, Ma JF (2017) Topochemical correlation between carbohydrates and lignin on Eucommia ulmoides cell wall from tissue to cell level. BioResources 12(1):1064–1076Google Scholar
- Kutscha NP, McOrmond RR (1972) The suitability of using fluorescence microscopy for studying lignification in balsam fir. In: Life sciences and agriculture experiment station, University of Maine, Orono, Maine, Techical Bulletin, p 62Google Scholar
- Li DL, Wu JQ, Peng WX, Xiao WF, Wu JG, Zhuo JY, Yuan TQ, Sun RC (2015) Effect of lignin on bamboo biomass self-bonding during hot-pressing: lignin structure and characterization. BioResources 10(4):6769–6782Google Scholar
- Ralph SA, Ralph J, Landucci L (2009) NMR database of lignin and cell wall model compounds. United States Forest Products Laboratory, Madison, WI, 2004. http://ars.usda.gov/Services/docs.htm?docid=10491. Accessed Jan 2009
- Sluiter A, Hames B, Ruiz R, Scarlata C, Sluiter J, Templeton D, Crocker D (2012) Determination of structural carbohydrates and lignin in biomass. In: National Renewable Energy Laboratory (NREL) laboratory analytical procedures (LAP) for standard biomass analysis. http://www.nrel.gov/docs/gen/fy13/42618.pdf. Accessed Aug 2012
- Wang K, Yang H, Guo S, Yao X, Sun RC (2013) Comparative characterization of degraded lignin polymer from the organosolv fractionation process with various catalysts and alcohols. J Appl Polym Sci 1:39673Google Scholar