Lignin can be broken down in aerobic conditions by peroxidase and a series of other fungal enzymes, it only forms those energy dense forms under anaerobic condi

Lignin can be broken down in aerobic conditions by peroxidase and a series of other fungal enzymes, it only forms those energy dense forms under anaerobic conditions and probably requires high pressures. The reason it is so difficult and only breaks down through oxidation is because it is quite complex, unlike the homogenous polymer chains of plastic that have many repeating monomers. https://www.researchgate.net/figure/Chemical-structure-of-lignin-source-lignoworks_fig1_315348668 https://www.researchgate.net/figure/Chemical-structure-of-li...