Potential of selected fungal species to degrade wheat straw, the most abundant plant raw material in Europe

Abstract

BackgroundStructural component of plant biomass, lignocellulose, is the most abundant renewable resource in nature. Lignin is the most recalcitrant natural aromatic polymer and its degradation presents great challenge. Nowadays, the special attention is given to biological delignification, the process where white-rot fungi take the crucial place owing to strong ligninolytic enzyme system. However, fungal species, even strains, differ in potential to produce high active ligninolytic enzymes and consequently to delignify plant biomass. Therefore, the goals of the study were characterization of Mn-oxidizing peroxidases and laccases of numerous mushrooms as well as determination of their potential to delignify wheat straw, the plant raw material that, according to annual yield, takes the first place in Europe and the second one in the world.ResultsDuring wheat straw fermentation, Lentinus edodes HAI 858 produced the most active Mn-dependent and Mn-independent peroxidases (1443.2 U L−1 and 1045.5 U L−1, respectively), while Pleurotus eryngii HAI 711 was the best laccase producer (7804.3 U L−1). Visualized bends on zymogram confirmed these activities and demonstrated that laccases were the dominant ligninolytic enzymes in the studied species. Ganoderma lucidum BEOFB 435 showed considerable ability to degrade lignin (58.5%) and especially hemicellulose (74.8%), while the cellulose remained almost intact (0.7%). Remarkable selectivity in lignocellulose degradation was also noted in Pleurotus pulmonarius HAI 573 where degraded amounts of lignin, hemicellulose and cellulose were in ratio of 50.4%:15.3%:3.8%.ConclusionsAccording to the presented results, it can be concluded that white-rot fungi, due to ligninolytic enzymes features and degradation potential, could be important participants in various biotechnological processes including biotransformation of lignocellulose residues/wastes in food, feed, paper and biofuels.

Ability of different edible fungi to degrade crop straw

“…Crop straw is a rich renewable resource, but it causes environmental pollution that is considered a major problem in modern agriculture (Novaes et al 2010; Sanderson 2011). Lignocellulose, which is abundant in crop straw, is the main component limiting straw degradation (Ćilerdžić et al 2017). Laccase and xylanase are the main components of lignocellulase.…”

Mechanistic insight in the selective delignification of wheat straw by three white-rot fungal species through quantitative 13C-IS py-GC–MS and whole cell wall HSQC NMR

“…Lignocellulosic biomass, such as wheat straw, is a highly abundant, valuable source of polysaccharides for the production of animal feed or biofuels and biochemicals [ 1 – 4 ]. The presence of lignin, however, hinders the conversion of these polysaccharides and, therefore, necessitates the use of pretreatments aimed at lignin removal or degradation.…”

Obtaining Cellulose-Available Raw Materials by Pretreatment of Common Agro-Forestry Residues With Pleurotus spp.

“…It is well known that species of the genus Pleurotus are among the most efficient and selective mineralizators of lignin in agriculture residues ( Stajić et al, 2004 , 2006 ; Dong et al, 2013 ; Singh and Singh, 2014 ; Aditiya et al, 2016 ; Mustafa et al, 2016 ; Bilal et al, 2017 ; Fang et al, 2018 ; Matrínez-Patiño et al, 2018 ; Alfaro et al, 2020 ; de Souza et al, 2020 ). Their remarkable degradation ability is primarily based on the synthesis of numerous highly active laccase isoforms ( Martínez et al, 1994 ; Muñoz et al, 1997 ; Ćilerdžić et al, 2017 ). However, the number and activity of secreted isoforms are not only genetically defined, but also depend on substrate type and composition.…”