1. Origin of lignin

Lignin is the second most abundant renewable biopolymer on Earth, after cellulose. Chemists were intrigued by this polymer early on, and it wasn't until the work of botanist A. P. Candolle in 1819 for the name lignin to appear . It soon became apparent that this polymer played a fundamental role in the emergence of plants on the earth's surface, as it confers mechanical properties such as compressive and tensile strength, as well as flexibility, to cell walls. Its hydrophobicity also enables cell walls to regulate water exchange with the external environment and limit the biodegradation of other constituents such as...