Rapid determination of syringyl: guaiacyl ratios using FT-Raman spectroscopy.
Lignin composition in relation to its basic phenylpropanoid units, particularly the syringyl to guaiacyl (S/G) ratio, is an important property for biomass characterization and varies greatly as a function of species, genotype and environment. A rapid screening method is highly desirable to assess lignin composition in a large number of samples. We have developed a nondestructive and label-free Fourier transform Raman (FT-Raman) spectroscopic method that is capable of rapidly and reliably measuring the S/G ratio with minimal sample preparation. A variety of feedstocks, including hardwood (Eucalyptus globulus), softwood (Pinus radiata), herbaceous plants (Zea mays, Panicum virgatum, and Sorghum bicolor), and a model dicot (Arabidopsis thaliana) were measured using this technique and the corresponding S/G ratio was calculated after spectral deconvolution based on the S and G bands identified using a known library of model compounds. The results obtained using this technique were successfully validated by pyrolysis-gas chromatography/mass spectrometry (pyro-GC/MS). This technique holds significant promise in the rapid screening of engineered feedstocks as part of a comprehensive screening methodology that is correlated with biomass recalcitrance.
Joint BioEnergy Institute, Physical Biosciences Division, Lawrence Berkeley National Laboratory, 5885 Hollis Street, Emeryville, California 94608, USA.
Lan
L
Sun
Patanjali
P
Varanasi
Fan
F
Yang
Dominique
D
Loqué
Blake A
BA
Simmons
Seema
S
Singh
D008031:Lignin / Q000032:analysis / Q000737:chemistry*; D010944:Plants / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013997:Time Factors
C434470:guaiacyl monolignol; C434469:syringyl monolignol; D008031:Lignin