• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Microbiology >The Key to Acetate: Metabolic Fluxes of Acetic Acid Bacteria under Cocoa Pulp Fermentation-Simulating Conditions
【24h】

The Key to Acetate: Metabolic Fluxes of Acetic Acid Bacteria under Cocoa Pulp Fermentation-Simulating Conditions

机译：乙酸的关键：可可浆发酵模拟条件下乙酸细菌的代谢通量

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Acetic acid bacteria (AAB) play an important role during cocoa fermentation, as their main product, acetate, is a major driver for the development of the desired cocoa flavors. Here, we investigated the specialized metabolism of these bacteria under cocoa pulp fermentation-simulating conditions. A carefully designed combination of parallel ~(13)C isotope labeling experiments allowed the elucidation of intracellular fluxes in the complex environment of cocoa pulp, when lactate and ethanol were included as primary substrates among undefined ingredients. We demonstrate that AAB exhibit a functionally separated metabolism during coconsumption of two-carbon and three-carbon substrates. Acetate is almost exclusively derived from ethanol, while lactate serves for the formation of acetoin and biomass building blocks. Although this is suboptimal for cellular energetics, this allows maximized growth and conversion rates. The functional separation results from a lack of phosphoenolpyruvate carboxykinase and malic enzymes, typically present in bacteria to interconnect metabolism. In fact, gluconeogenesis is driven by pyruvate phosphate dikinase. Consequently, a balanced ratio of lactate and ethanol is important for the optimum performance of AAB. As lactate and ethanol are individually supplied by lactic acid bacteria and yeasts during the initial phase of cocoa fermentation, respectively, this underlines the importance of a well-balanced microbial consortium for a successful fermentation process. Indeed, AAB performed the best and produced the largest amounts of acetate in mixed culture experiments when lactic acid bacteria and yeasts were both present.
机译：乙酸细菌（AAB）在可可发酵过程中起着重要作用，因为其主要产品乙酸盐是开发所需可可风味的主要驱动力。在这里，我们调查了可可浆发酵模拟条件下这些细菌的专门代谢。当将乳酸和乙醇作为主要成分包括在不确定的成分中时，精心设计的平行〜（13）C同位素标记实验组合可以阐明可可浆复杂环境中的细胞内通量。我们证明了AAB在共同消耗两碳和三碳底物的过程中展现出功能分离的新陈代谢。乙酸盐几乎完全来自乙醇，而乳酸盐则用于形成丙酮酸和生物质结构单元。尽管对于细胞能量学来说这不是最理想的，但是这允许最大化的生长和转化率。功能分离是由于缺乏磷酸烯醇丙酮酸羧激酶和苹果酸酶而引起的，通常存在于细菌中以相互连接新陈代谢。实际上，糖原异生是由丙酮酸磷酸二激酶驱动的。因此，乳酸和乙醇的平衡比例对于AAB的最佳性能很重要。由于乳酸和乙醇分别在可可发酵的初始阶段分别由乳酸菌和酵母菌提供，这突出了平衡良好的微生物联盟对成功发酵过程的重要性。实际上，当乳酸菌和酵母菌同时存在时，AAB在混合培养实验中表现最好，产生的乙酸盐最多。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号