Pelleting can increase the efficiency of handling and transportation of biomass. Pretreatment obtains lignin fragments by disrupting the lignocellulosic structure of biomass and ensures the high-quality compressed pellets. In this study, solid-state fermentation (SSF) is used as a biological method to improve the quality of pellets of oat straw. SSF of oat straw using Trametes versicolor 52J (TV52J) and Phanerochaete chrysosporium (PC) was conducted. Response surface methodology (RSM) was employed by using a four-factor, three-level Box–Behnken design with fermentation time (days), moisture content (%), particle size (mm), and fermentation temperature (°C) as independent parameters. Pellet density, dimensional stability, and tensile strength were the response variables. The optimization options of fermentation time (33.96 and 35 days), moisture content (70%), particle size (150 and 50 mm), and fermentation temperature (22°C) of oat straw pretreated with these two fungal strains were obtained. The microscopic structural changes of oat straw caused by biological pretreatment were investigated by scanning electron microscopy (SEM). Observation results of SEM showed that the connection between single fibers became relatively loose, and this was beneficial to improve the physical quality of the pellets.

中文翻译：

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燕麦秸秆固态发酵生物预处理提高颗粒物理质量

造粒可以提高生物质的处理和运输效率。预处理通过破坏生物质的木质纤维素结构获得木质素碎片，并确保高质量的压缩颗粒。在本研究中，固态发酵 (SSF) 被用作提高燕麦秸秆颗粒质量的生物方法。使用 Trametes versicolor 52J (TV52J) 和 Phanerochaete chrysosporium (PC) 对燕麦秸秆进行 SSF。响应面法 (RSM) 使用四因素、三水平 Box-Behnken 设计，发酵时间（天）、水分含量（%）、粒径（mm）和发酵温度（°C）作为独立参数。颗粒密度、尺寸稳定性和拉伸强度是响应变量。发酵时间（33.96天和35天）的优化选项，获得了用这两种真菌菌株预处理的燕麦秸秆的水分含量 (70%)、粒径 (150 和 50 mm) 和发酵温度 (22°C)。通过扫描电子显微镜（SEM）研究了生物预处理引起的燕麦秸秆微观结构变化。SEM观察结果表明，单纤维之间的连接变得相对松散，这有利于提高颗粒的物理质量。