Shiitake cultivation as biological preprocessing of lignocellulosic feedstocks – Substrate changes in crystallinity, syringyl/guaiacyl lignin and degradation-derived by-products

• Published in: Bioresource technology Vol. 344; no. Pt B; p. 126256
• Main Authors: Chen, Feng, Martín, Carlos, Lestander, Torbjörn A., Grimm, Alejandro, Xiong, Shaojun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-01-2022
• Subjects: Bioenergi; Bioenergy; Fungal pretreatment; Glucans; Hardwood substrate; Lignin; Lignocellulose degradation; Phenolic components; PLS model; Shiitake Mushrooms; Wood; PLS model; Hardwood substrate; Lignocellulose degradation; Fungal pretreatment; Phenolic components
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2021.126256

•Three wood species combined with whey additions were designed for shiitake substrate.•Whey affected more fungal production and lignocellulose degradation than wood species.•Low nitrogen maximise delignification but minimise glucan degradation.•Delignification was correlated with reduction of syringyl-to-guaiacyl ratio.•Slight changes in substrate crystallinity but phenolics increased up to seven-fold.
Formulation of substrates based on three hardwood species combined with modulation of nitrogen content by whey addition (0–2%) was investigated in an experiment designed in D-optimal model for their effects on biological preproceesing of lignocellulosic feedstock by shiitake mushroom (Lentinula edodes) cultivation. Nitrogen loading was shown a more significant role than wood species for both mushroom production and lignocellulose degradation. The fastest mycelial colonisation occurred with no nitrogen supplementation, but the highest mushroom yields were achieved when 1% whey was added. Low nitrogen content resulted in increased delignification and minimal glucan consumption. Delignification was correlated with degradation of syringyl lignin unit, as indicated by a significant reduction (41.5%) of the syringyl-to-guaiacyl ratio after cultivation. No significant changes in substrate crystallinity were observed. The formation of furan aldehydes and aliphatic acids was negligible during the pasteurisation and fungal cultivation, while the content of soluble phenolics increased up to seven-fold.