Lignin Biodegradation with Fungi, Bacteria and Enzymes for Producing Chemicals and Increasing Process Efficiency

Importance of Mediators for Lignin Degradation by Fungal Laccase

“…The concomitant decrease of the overall S units involved in nonoxidized β- O -4 bonds (A S and A G units) and the increase of oxidized S units (δ C /δ H 104–110/7.1–7.5) confirm the ability of VA to efficiently mediate lignin oxidation. In both cases, no oxidized G units were observed, suggesting that β- O -4 involving S units are easier to oxidize/cleave than that involving G. This corroborates literature on β- O -4 model bonds’ degradation by LA and mediator. ,,, An overview of S/G type simple phenolic compounds and mediators redox potential is shown in Table . As a general trend, two simple phenols with similar structure differing only by the substitution of one (G) or two (S) methoxy groups on the aromatic ring have different redox potentials, with the disubstituted (S) phenol having the lowest.…”

“…In nature, micro-organisms such as bacteria or wood-rot fungi have developed strategies to degrade and even catabolize the resulting aromatic compounds into carbon and energy. − These natural depolymerization processes usually combine internal and external enzymes. Different groups of enzymes involved in this process have been identified.…”

“…In both cases, no oxidized G units were observed, suggesting that β-O-4 involving S units are easier to oxidize/cleave than that involving G. This corroborates literature on β-O-4 model bonds' degradation by LA and mediator. 5,16,25,39 An overview of S/G type simple phenolic compounds and mediators redox potential is shown in Table 3.…”

Prediction of solubility parameters of lignin and ionic liquids using multi-resolution simulation approaches

“…The higher removal of lignin from hardwood and grassy biomasses in [Ch][Lys] is due to the presence of larger amounts of ether linkages 60–80%. 10,73 These ether linkages are highly solvated by [Ch][Lys] when compared to C–C linkages (softwood biomass). 62 The main structural differences between these three types of lignin are a lower content of free phenolic hydroxyl groups.…”

“…2 Lignin solubilization and subsequent fractionation remain a key barrier for biorefineries due to its recalcitrance, heterogeneity, strong interactions, and hydrophobicity. 10 Hence, suitable solvents are required to enable lignin solubilization and separation.…”