Liu Shan, Li Xin, Wu Shubiao, He Jing, Pang Changle, Deng Yu, Dong Renjie
Key Laboratory of Clean Utilization Technology for Renewable Energy in Ministry of Agriculture, College of Engineering, China Agricultural University, Beijing, 100083, People's Republic of China.
Appl Biochem Biotechnol. 2014 Nov;174(5):1907-18. doi: 10.1007/s12010-014-1185-7. Epub 2014 Aug 23.
Corn stover silage (CSS) was pretreated by Phanerochaete chrysosporium in solid-state fermentation (SSF), to enhance methane production via subsequent anaerobic digestion (AD). Effects of washing of corn stover silage (WCSS) on the lignocellulosic biodegradability in the fungal pretreatment step and on methane production in the AD step were investigated with comparison to the CSS. It was found that P. chrysosporium had the degradation of cellulose, hemicellulose, and lignin of CSS up to 19.9, 32.4, and 22.6 %, respectively. Consequently, CSS pretreated by 25 days achieved the highest methane yield of 265.1 mL/g volatile solid (VS), which was 23.0 % higher than the untreated CSS. However, the degradation of cellulose, hemicellulose, and lignin in WCSS after 30 days of SSF increased to 45.9, 48.4, and 39.0 %, respectively. Surface morphology and Fourier-transform infrared spectroscopy analyses also demonstrated that the WCSS improved degradation of cell wall components during SSF. Correspondingly, the pretreatment of WCSS improved methane production by 19.6 to 32.6 %, as compared with untreated CSS. Hence, washing and reducing organic acids (such as lactic acid, acetic acid, propionic acid, and butyric acid) present in CSS has been proven to further improve biodegradability in SSF and methane production in the AD step.
玉米秸秆青贮饲料（CSS）通过黄孢原毛平革菌在固态发酵（SSF）中进行预处理，以提高后续厌氧消化（AD）过程中的甲烷产量。与CSS相比，研究了水洗玉米秸秆青贮饲料（WCSS）对真菌预处理步骤中木质纤维素生物降解性以及AD步骤中甲烷产量的影响。结果发现，黄孢原毛平革菌对CSS中纤维素、半纤维素和木质素的降解率分别高达19.9%、32.4%和22.6%。因此，经过25天预处理的CSS实现了最高甲烷产量，为265.1 mL/g挥发性固体（VS），比未处理的CSS高出23.0%。然而，在固态发酵30天后，WCSS中纤维素、半纤维素和木质素的降解率分别提高到45.9%、48.4%和39.0%。表面形态和傅里叶变换红外光谱分析也表明，WCSS在固态发酵过程中改善了细胞壁成分的降解。相应地，与未处理的CSS相比，WCSS的预处理使甲烷产量提高了19.6%至32.6%。因此，已证明水洗并减少CSS中存在的有机酸（如乳酸、乙酸、丙酸和丁酸）可进一步提高固态发酵中的生物降解性以及AD步骤中的甲烷产量。
