Analysis of lignin isolated from poplar cell suspension cultures

摘要

We have investigated lignin structures in pure primary cell walls. Poplar cell suspension cultures, Populus tremula x tremuloides, were harvested after 7, 14 and 21 days of growth. Carbohydrate monomer analysis also points at the presence of primary wall exclusively. Confocal microscopy of the cells dyed with acriflavin demonstrates that lignin is present. Klason content increases during growth from 0.7 to 3.9 percent. GC analysis of samples subjected to thioacidolysis shows that the lignin constitutes of guaiacyl units as compared to poplar wood which have syringyl as the main monomer. The amount of monomers per unit Klason lignin is lower than in wood and it decreases during cultivation possibly indicating a larger relative content of carbon-carbon bonds in the polymeric lignin in the cell cultures as compared to wood. Five lignin structures were identified with massspectrometry.