Klausen Sarah J, Romero-Soto Luis A, Liaqat Ayesha, Dehghanmanshadi Zahra, Strætkvern Knut O, Xiong Shaojun, Martín Carlos
Department of Biotechnology, University of Inland Norway, Hamar, Norway.
Universidad Privada Boliviana, Facultad de Ingeniería y Arquitectura, La Paz, Bolivia.
Bioengineered. 2025 Dec;16(1):2536443. doi: 10.1080/21655979.2025.2536443. Epub 2025 Jul 30.
Spent mushroom substrate (SMS), the main by-product of mushroom cultivation, is a source of sugars that can be released by saccharification. This work aimed at investigating the enzymatic saccharification of the polysaccharides of the SMS of shiitake () and oyster mushroom () and exploring the lignin extraction from the saccharification residues. First, analytical enzymatic saccharification (AES) with a cellulase cocktail and an experimental hemicellulase-rich preparation was applied. AES revealed higher digestibility of both polysaccharides for shiitake SMS than for oyster mushroom SMS. Using the cellulase cocktail, shiitake SMS resulted in a digestibility above 80% and 70% (w/w) for cellulose and xylan, respectively, while the maximum values for oyster mushroom SMS were 52% and 32% (w/w). The experimental enzyme preparation resulted in lower cellulose digestibility and higher xylan digestibility. Still, the saccharification trend between the two SMS types remained unchanged. To enhance the enzymatic saccharification of oyster mushroom SMS, hydrothermal treatment was applied. The treatment improved the enzymatic digestibility of cellulose by up to 84%. A validation experiment at larger scale showed that hydrothermally treated oyster mushroom SMS had a comparable overall conversion with non-treated shiitake SMS. Following a biorefinery strategy, lignin was extracted from the residues of the preparative enzymatic saccharification using the green solvent γ-valerolactone under different temperatures and holding times. The extracted product contained 98.8% lignin and did not contain cellulose or xylan. The results of this study provide the grounds for biorefinery processes enabling recovery of bioactive compounds, fermentable sugars, and high-quality lignin from SMS.
废菌糠（SMS）是蘑菇栽培的主要副产品，是一种可通过糖化作用释放糖的来源。本研究旨在探讨香菇（）和平菇（）废菌糠中多糖的酶促糖化作用，并探索从糖化残渣中提取木质素的方法。首先，使用纤维素酶混合物和一种富含半纤维素的实验性酶制剂进行分析性酶促糖化（AES）。AES结果显示，香菇废菌糠中两种多糖的消化率均高于平菇废菌糠。使用纤维素酶混合物时，香菇废菌糠中纤维素和木聚糖的消化率分别高于80%和70%（w/w），而平菇废菌糠的最大值分别为52%和32%（w/w）。实验性酶制剂导致纤维素消化率较低而木聚糖消化率较高。不过，两种废菌糠之间的糖化趋势保持不变。为提高平菇废菌糠的酶促糖化率，进行了水热处理。该处理使纤维素的酶促消化率提高了84%。大规模验证实验表明，水热处理后的平菇废菌糠与未处理的香菇废菌糠具有相当的总转化率。按照生物精炼策略，使用绿色溶剂γ-戊内酯在不同温度和保温时间下从制备性酶促糖化残渣中提取木质素。提取的产物含有98.8%的木质素，且不含纤维素或木聚糖。本研究结果为从废菌糠中回收生物活性化合物、可发酵糖和高质量木质素的生物精炼工艺提供了依据。
