Rumen liquid is excellent to effectively degrade lignocellulose. In this study, the suitable rice straw load during anaerobic fermentation of rice straw with rumen liquid as inoculum was explored to improve volatile fatty acid (VFA) production. At 10.0% rice straw load, the highest VFA concentration reached 10821.4 mg/L, and acetic acid and propionic acid were the main components. In 10.0% rice straw load system, high concentration of soluble chemical oxygen demand (SCOD) was also observed, and the enzymatic activities at 48 h were higher than those at other rice straw loads. At 10.0% rice straw load, lower diversity and richness of rumen bacteria were found than those at other rice straw loads. Bacteroides, Prevotella, and Ruminococcus were the main rumen bacteria during rice straw degradation, and the rumen bacteria might secret effective lignocellulolytic enzymes to enhance the hydrolysis and acidogenesis of rice straw. The determination of suitable rice straw load will be beneficial to the application of rumen liquid as inoculum in actual production.

瘤胃液非常有效地降解木质纤维素。在这项研究中，探索了在以瘤胃液作为接种物的稻草厌氧发酵过程中合适的稻草负荷，以提高挥发性脂肪酸（VFA）的产量。在稻草负荷为10.0％时，最高VFA浓度达到10821.4 mg / L，其中乙酸和丙酸是主要成分。在10.0％的稻草负载系统中，还观察到高浓度的可溶性化学需氧量（SCOD），并且48 h的酶活高于其他稻草负载。在稻草负载为10.0％时，发现瘤胃细菌的多样性和丰富度低于其他稻草负载。拟杆菌，小球藻和瘤球菌是稻草降解过程中主要的瘤胃细菌，瘤胃细菌可能分泌有效的木质纤维素分解酶来增强稻草的水解和酸化作用。确定合适的稻草负载量将有利于瘤胃液作为接种物在实际生产中的应用。