Chen Lianmin, Shen Yizhao, Wang Chao, Ding Luoyang, Zhao Fangfang, Wang Mengzhi, Fu Jingyuan, Wang Hongrong
Laboratory of Metabolic Manipulation of Herbivorous Animal Nutrition, College of Animal Science and Technology, Yangzhou University, Yangzhou, China.
Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, Netherlands.
Front Microbiol. 2019 Feb 7;10:162. doi: 10.3389/fmicb.2019.00162. eCollection 2019.
is an ecologically important rumen bacterium that metabolizes lactate and relieves rumen acidosis (RA) induced by a high-grain-diet. Understanding the regulatory mechanisms of the lactate metabolism of this species in RA conditions might contribute to developing dietary strategies to alleviate RA. was co-cultured with four lactate producers (, , , and ) and a series of substrate starch doses (1, 3, and 9 g/L) were used to induce one normal and two RA models (subacute rumen acidosis, SARA and acute rumen acidosis, ARA) under batch conditions. The associations between bacterial competition and the shift of organic acids' (OA) accumulation patterns in both statics and dynamics manners were investigated in RA models. Furthermore, we examined the effects of substrate lactate concentration and pH on lactate degradation pattern and genes related to the lactate utilizing pathways in the continuous culture. The positive growth of and caused OA accumulation in the SARA model to shift from lactate to butyrate and resulted in pH recovery. Furthermore, both the quantities of substrate lactate and pH had remarkable effects on lactate utilization due to the transcriptional regulation of metabolic genes, and the lactate utilization in was more sensitive to pH changes than to the substrate lactate level. In addition, compared with associations based on statics data, associations discovered from dynamics data showed greater significance and gave additional explanations regarding the relationships between bacterial competition and OA accumulation.
是一种在生态上具有重要意义的瘤胃细菌，它能代谢乳酸并缓解高谷物日粮诱导的瘤胃酸中毒（RA）。了解该物种在RA条件下乳酸代谢的调控机制可能有助于制定缓解RA的日粮策略。将其与四种乳酸产生菌（、、、和）共培养，并在分批条件下使用一系列底物淀粉剂量（1、3和9 g/L）诱导一个正常模型和两个RA模型（亚急性瘤胃酸中毒，SARA和急性瘤胃酸中毒，ARA）。在RA模型中，以静态和动态方式研究了细菌竞争与有机酸（OA）积累模式变化之间的关联。此外，我们在连续培养中研究了底物乳酸浓度和pH对乳酸降解模式以及与乳酸利用途径相关基因的影响。在SARA模型中，和的正向生长导致OA积累从乳酸转变为丁酸，并使pH恢复。此外，由于代谢基因的转录调控，底物乳酸的量和pH对乳酸利用均有显著影响，并且对pH变化的敏感性高于底物乳酸水平。此外，与基于静态数据的关联相比，从动态数据中发现的关联显示出更大的显著性，并对细菌竞争与OA积累之间的关系给出了额外的解释。
