Integrated production of edible mushroom (Auricularia auricular-judae), fermentable sugar and solid biofuel

• Published in: Renewable energy 2021-06, Vol.170, p.172-180
• Main Authors: Chen, Feng, Grimm, Alejandro, Eilertsen, Lill, Martín, Carlos, Arshadi, Mehrdad, Xiong, Shaojun
• Format: Article
• Language: English
• Subjects: Bioethanol; Biological pretreatment; Edible mushroom; Energy saving; Förnyelsebar bioenergi; Renewable Bioenergy Research; Solid biofuel
• ISSN: 0960-1481; 1879-0682; 1879-0682
• DOI: 10.1016/j.renene.2021.01.124

This study aimed to develop an energy- and resource-efficient process for the coproduction of edible mushroom, fermentable sugar and solid biofuel from wood residues. A promising potential was revealed for wood ear fungus (Auricularia auricular-judae), which yielded about 200 g mushroom per kg dry birch-based substrate, with concomitant degradation of 76.8 and 85.7% of lignin and xylan, respectively, in the substrate. Substrate pasteurisation by hot-air (85–100 °C) was as effective as by energy intensive autoclaving (121 °C), resulting comparable mushroom growth and degradation of lignocellulose. The spent mushroom substrate (SMS) contained 28–33% glucan, which upon analytical enzymatic saccharification released around 46% of the potentially-achievable glucose, corresponding to a 2.3–fold enzymatic digestibility compared with that of the raw substrate. The solid leftover generated after enzymatic hydrolysis revealed high thermal energy value and promising combustion characteristics, showing a plausibility to be recycled as solid fuel for self-supporting energy system and space heating. •Wood residues have potential for coproduction of food, bioethanol and solid fuel.•No difference between heat treatments (85–121 °C) on fungal yield and SMS compositions.•Wood ear SMS resulted in 2.3 times higher glucan digestibility than raw substrate.•Leftover from enzymatic hydrolysis showed promising combustion characteristics.