Supplementing Glycerol to Inoculum Induces Changes in pH, SCFA Profiles, and Microbiota Composition in In-Vitro Batch Fermentation

This study investigated the effect of supplementing glycerol to inoculum on in vitro fermentation and whether an enhanced buffer capacity of medium could maintain the pH stability during in vitro batch fermentation, subsequently improve the accuracy of short chain fatty acids (SCFAs) determination, especially propionate. Two ileal digesta were fermented by pig fecal inoculum with or without glycerol (served as anti-frozen inoculum or frozen inoculum) in standard buffer or enhanced buffer solution (served as normal or modified medium).

本研究考察了向接种物（inoculum）中添加甘油对体外发酵的影响，同时探究提升培养基缓冲容量是否可在体外分批发酵过程中维持pH稳定，进而提高短链脂肪酸（short chain fatty acids, SCFAs）定量检测的准确性，尤其是丙酸的测定精度。实验以猪粪便接种物为发酵接种源，对两份回肠食糜开展发酵实验：接种物分为添加甘油（作为抗冻接种物）与不添加甘油（作为冷冻接种物）两组，发酵所用缓冲液则分为标准缓冲液（普通培养基）与增强缓冲液（改性培养基）两种。