Enzymes face several challenges in the degradation of macromolecular lignin [49]. As mentioned earlier, this substrate is a large heterogeneous polymer and very difficult to degrade by microbes. Indeed, lignin does not contain enzymatically hydrolysable linkages and is stereo-irregular. For lignin degradation, the enzymes or agents must be oxidative. Many extracellular enzymes involved in lignin degradation are, as mentioned earlier, LiPs (LiPs, ligninases, EC 1.11.1.14), manganese peroxidases (MnPs, Mn-dependent peroxidases, EC 1.11.1.13) and Lacs (benzenediol:oxygen oxidoreductase, EC 1.10.3.2). Further, some accessory enzymes are also involved in hydrogen peroxide production. Glyoxal oxidase (GLOX) and aryl alcohol oxidase (AAO) (EC 1.1.3.7) belong to this group. LiPs and MnPs are heme-containing glycoproteins, which require hydrogen peroxide as an oxidant [49, 98].