Liu Chang, Ge Jing, Dai Jiaqi, Qu Mingren, Ouyang Kehui, Qiu Qinghua
Jiangxi Province Key Laboratory of Animal Nutrition and Feed, College of Animal Science and Technology, Jiangxi Agricultural University, Nanchang 330045, China.
Animals (Basel). 2024 Dec 24;15(1):5. doi: 10.3390/ani15010005.
This study aimed to investigate the effects of different storage times of the mixed inoculum on in vitro rumen fermentation characteristics, microbial diversity, and community composition. The experiment was divided into five groups, with mixed inoculum composed of fresh rumen fluid and culture medium being stored at 39 °C for 0 h (H0), 12 h (H12), 24 h (H24), 36 h (H36), and 48 h (H48). After 48 h of in vitro fermentation, the fermentation fluid was collected to assess rumen fermentation characteristics and microbial community composition. The H24 group showed higher total gas production, ammoniacal nitrogen levels, and total volatile fatty acids, as well as higher concentrations of individual volatile fatty acids except propionate, compared to the H0 and H48 groups ( < 0.05). The Shannon and Simpson evenness indices were significantly higher in the H0, H12, and H24 groups than in the H48 group ( < 0.05). A total of nine phyla and sixteen genera involved in starch and fiber degradation were found to be more abundant in the H24 or H48 groups ( < 0.05). Moreover, nine predicted metabolic pathways were observed to be significantly enriched in either the H24 or H48 group ( < 0.05). Both principal coordinates analysis (PCoA) and non-metric multidimensional scaling (NMDS) analysis revealed distinct clustering patterns among the H0, H12, H24, H36, and H48 groups, and analysis of similarities (ANOSIM) confirmed these significant differences (R = 1.00, < 0.05). This study demonstrates that the storage time of mixed inoculum influences rumen fermentation characteristics and microbial community composition in a time-dependent manner. It is recommended to use a mixed inoculum that has been stored within 24 h in an anaerobic environment at 39 °C for in vitro rumen fermentation tests. This study offers valuable microbial insights into the storage strategies for mixed inoculum, thereby improving the methodologies for variable control in in vitro rumen fermentation techniques.
本研究旨在探讨混合接种物不同储存时间对体外瘤胃发酵特性、微生物多样性和群落组成的影响。实验分为五组，将由新鲜瘤胃液和培养基组成的混合接种物在39℃下储存0小时（H0）、12小时（H12）、24小时（H24）、36小时（H36）和48小时（H48）。体外发酵48小时后，收集发酵液以评估瘤胃发酵特性和微生物群落组成。与H0和H48组相比，H24组显示出更高的总产气量、氨氮水平和总挥发性脂肪酸，以及除丙酸外更高的各挥发性脂肪酸浓度（P<0.05）。H0、H12和H24组的香农和辛普森均匀度指数显著高于H48组（P<0.05）。共发现9个门和16个参与淀粉和纤维降解的属在H24或H48组中更为丰富（P<0.05）。此外，观察到9条预测的代谢途径在H24或H48组中显著富集（P<0.05）。主坐标分析（PCoA）和非度量多维尺度分析（NMDS）均显示H0、H12、H24、H36和H48组之间存在明显的聚类模式，相似性分析（ANOSIM）证实了这些显著差异（R = 1.00，P<0.05）。本研究表明，混合接种物的储存时间以时间依赖性方式影响瘤胃发酵特性和微生物群落组成。建议在39℃厌氧环境下将储存时间在24小时内的混合接种物用于体外瘤胃发酵试验。本研究为混合接种物的储存策略提供了有价值的微生物见解，从而改进了体外瘤胃发酵技术中变量控制的方法。
