Multi-catalysis reactions: new prospects and challenges of biotechnology to valorize lignin

Abstract

Considerable effort has been dedicated to the chemical depolymerization of lignin, a biopolymer constituting a possible renewable source for aromatic value-added chemicals. However, these efforts yielded limited success up until now. Efficient lignin conversion might necessitate novel catalysts enabling new types of reactions. The use of multiple catalysts, including a combination of biocatalysts, might be necessary. New perspectives for the combination of bio-and inorganic catalysts in one-pot reactions are emerging, thanks to green chemistry-driven advances in enzyme engineering and immobilization and new chemical catalyst design. Such combinations could offer several advantages, especially by reducing time and yield losses associated with the isolation and purification of the reaction products, but also represent a big challenge since the optimal reaction conditions of bio-and chemical catalysis reactions are often different. This minireview gives an overview of bio-and inorganic catalysts having the potential to be used in combination for lignin depolymerization. We also discuss key aspects to consider when combining these catalysts in one-pot reactions.

The ligninolytic peroxidases in the genus Pleurotus: divergence in activities, expression, and potential applications

“…(b) Enzyme technology: several approaches have been proposed to improve the functionality of fungal peroxidases by methods such as enzyme immobilization, crosslinking with other enzymes and combination of bioand inorganic catalysts (Rao et al 2014;Vásquez et al 2014). For example, Gasser et al (2012) reviewed new perspectives for the combination of bio-and inorganic catalysts in one-pot reactions, having the potential to be used for lignin depolymerization for production of added-value aromatic chemicals. VP is one candidate that can be used as a biocatalyst in such systems.…”

Direct rate assessment of laccase catalysed radical formation in lignin by electron paramagnetic resonance spectroscopy

“…Hence, a significant potential exists for exploitation of lignin to create value added products without compromising internal process requirements of biorefineries, and development of e.g. aromatic derived chemicals or functionalized polymeric materials by various catalytic technologies has already been reported in the literature [2][3][4][5][6].…”

“…8068-03-9) obtained from SigmaAldrich (Milwaukee, WI, USA) (SOL) and a beech organosolv lignin (BOL) produced at Thünen Institute of Wood Research (Hamburg, Germany) [21]. These organosolv lignins were dry powders with a volume-based particle size of D [4,3] Wheat straw lignin (WSL) was a hydrothermally pretreated wheat straw sample that had been exhaustively enzymatically treated with a Cellic CTec2 enzyme cocktail from Novozymes (Bagsvaerd, Denmark). The wheat straw had first been hydrothermally pre-treated in a pilot plant facility (10 min, 190 °C) according to [22].…”

“…After the first enzymatic treatment, the suspension was centrifuged for 20 min at 5350 g and the pellet obtained washed twice with deionized water; this procedure was repeated twice. The final wheat straw lignin pellet resulting after three rounds of enzymatic treatment was washed, dried at 70 °C, ground and sieved to obtain a resulting volume-based particle size of D [4,3] = 15.8 µm. This wheat straw lignin (WSL) sample contained 43.7 wt% of Klason lignin (and 37.8 wt%cellulose, 9.2wt% hemicellulose, and 6.1wt% ash).…”

Fungal Bioremediation of Emerging Micropollutants in Municipal Wastewaters

“…The main restriction of haem containing enzymes is their poor stability to environmental conditions and reaction products as well as rapid deactivation of hydrogen peroxide (Buchanan and Han 1999, Buchanan and Nicell 1998, Gasser et al 2012). Even in model, sterile and buffered solutions, 90% of lignin peroxidase activity was lost after 24 hours (Wang et al 2012).…”