Rumen liquid can effectively degrade lignocellulosic biomass, in which rumen microorganisms play an important role. In this study, transformation of bacterial community structure in rumen liquid anaerobic digestion of rice straw was explored. Results showed that rice straw was efficiently hydrolyzed and acidified, and the degradation efficiency of cellulose, hemicellulose and lignin reached 46.2%, 60.4%, and 12.9%, respectively. The concentration of soluble chemical oxygen demand (SCOD) and total volatile fatty acid (VFA) reached 12.9 and 8.04 g L^-1. The high-throughput sequencing results showed that structure of rumen bacterial community significantly changed in anaerobic digestion. The Shannon diversity index showed that rumen bacterial diversity decreased by 32.8% on the 5^th day of anaerobic digestion. The relative abundance of Prevotella and Fibrobacter significantly increased, while Ruminococcus significantly decreased at the genus level. The Spearman correlation heatmap showed that pH and VFA were the critical factors affecting the rumen bacterial community structure. The function prediction found that rumen bacteria mainly functioned in carbohydrate transport and metabolism, which might contain a large number of lignocellulose degrading enzyme genes. These studies are conducive to the better application of rumen microorganisms in the degradation of lignocellulosic biomass.

瘤胃液可有效降解木质纤维素生物质，其中瘤胃微生物起重要作用。本研究探讨了稻草瘤胃液厌氧消化过程中细菌群落结构的转化。结果表明，稻草能被有效地水解和酸化，纤维素，半纤维素和木质素的降解效率分别达到46.2％，60.4％和12.9％。可溶性化学需氧量（SCOD）和总挥发性脂肪酸（VFA）的浓度分别达到12.9和8.04 g L ^-1。高通量测序结果表明，瘤胃细菌群落的结构在厌氧消化中发生了显着变化。香农多样性指数表明，瘤胃细菌多样性在5^日下降了32.8％。厌氧消化的一天。在属水平上，普氏杆菌和纤维杆菌的相对丰度显着增加，而鲁米诺球菌显着降低。Spearman相关热图显示，pH和VFA是影响瘤胃细菌群落结构的关键因素。功能预测发现，瘤胃细菌主要在碳水化合物的运输和代谢中起作用，其中可能含有大量的木质纤维素降解酶基因。这些研究有利于瘤胃微生物在木质纤维素生物质降解中的更好应用。