不同有机基质在细菌代谢途径中的不成比例的二氧化碳外流导致了对碳使用效率的可变贡献
Caroll M Mendonca1,2, Lichun Zhang3, Jacob R Waldbauer3
1Department of Biological and Environmental Engineering, College of Agriculture and Life Sciences, Cornell University, Ithaca, New York 14853, United States.
Environmental science & technology
|June 11, 2024
概括
土壤微生物通过确定碳利用效率 (CUE) 来控制碳循环. 这项研究揭示了代谢途径,而不仅仅是基质化学,决定了CUE,影响了全球二氧化碳预算.
科学领域:
- 微生物学 微生物学
- 生物地质化学生物地质化学
- 代谢工程是代谢工程.
背景情况:
- 微生物有机物流动对陆地二氧化碳 (CO2) 预算产生重大影响.
- 碳利用效率 (CUE) 量化了微生物将有机碳分成生物质和二氧化碳排放.
- 对CUE变异性的现有理论受到挑战,代谢策略涉及基质氧化状态.
研究的目的:
- 调查微生物碳利用效率 (CUE) 的变化背后的代谢机制.
- 阐明土壤细菌如何处理不同的碳基质并影响CUE.
- 为预测微生物碳循环提供一种以代谢为导向的框架.
主要方法:
- 在*Pseudomonas putida*中使用13C-代谢和13C-代谢流量分析进行多组学研究.
- 通过代谢途径追踪来自纤维素的糖碳和与素相关的芳香碳.
- 蛋白质组学分析以确定酶级调节点.
主要成果:
- 糖碳被引导到糖解和酸路径中,而芳香碳进入三酸循环.
- 与芳香碳相比,糖碳在二氧化碳排放中的投资减少了3倍.
- 酶调节主要发生在基质吸收和初始代谢过程中,控制下游代谢分割.
结论:
- 由初始代谢驱动的代谢分离,在土壤细菌中决定了基质依赖的CUE.
- 这些发现支持一种以代谢为导向的方法,用于预测微生物将有机物转化为二氧化碳.
- 了解这些代谢机制对于准确建模地球碳循环至关重要.
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