含有细胞质酸盐氧化降解酶的酸盐氧化细菌的动力可塑性
Ui-Ju Lee1, Joo-Han Gwak2,3, Christiana Abiola1
1Department of Biological Sciences and Biotechnology, Chungbuk National University, Cheongju, Republic of Korea.
The ISME journal
|February 27, 2026
概括
细胞质亚酸盐氧化还原酶 (cNXR) 细菌根据pH和亚酸盐水平动态调整其亚酸盐亲和力,这与周围细胞质亚酸盐氧化还原酶 (pNXR) 细菌不同. 这种可塑性使得Nitrobacter能够在各种环境中壮成长.
科学领域:
- 微生物生理学和生物化学
- 环境微生物学环境微生物学
- 生物地质化学循环 生物地质化学循环
背景情况:
- 酸盐氧化细菌 (NOB) 对于化至关重要,它们将酸盐转化为酸盐.
- NOB利用周等离子体 (pNXR) 或细胞质 (cNXR) 酸盐氧化还原酶,影响酸盐亲和力和能量产量.
- 传统上,含有cNXR的NOB被认为是低亲和度的,适应高化物和中性pH.
研究的目的:
- 为了研究cNXR NOB中酸盐亲和力的pH和基质依赖的调制.
- 为了比较cNXR NOB与pNXR NOB的动力可塑性.
- 阐明cNXR NOB中酸盐亲和度调节的基础分子机制.
主要方法:
- 在不同度的亚酸盐下种植Nitrobacter winogradskyi Nb-255 (1mM和10mM).
- 在不同的pH值 (7.5和5.5) 下测量表面Km (Km(app)) 和特定亲和力 (ao).
- 动力抑制测定以确定涉及的传送器和机制.
主要成果:
- 在低酸盐条件下种植的Nitrobacter winogradskyi表现出高酸盐亲和力,相当于PNXR NOB.
- 当在高化物中生长时,细胞在pH 7.5时表现出低亲和力,但在pH 5.5.时迅速增加亲和力.
- 这种依赖pH的可塑性在pNXR NOB中不存在,并且与NarK和NirC载体之间的切换有机械联系,从而增强细胞内酸盐的可用性.
结论:
- cNXR NOB具有一种新的机制,可以通过对酸盐度和pH的反应进行载体级调节来动态调节酸盐亲和力.
- 这种动力可塑性解释了Nitrobacter在酸性,低化物环境中的生态成功.
- 这些发现挑战了对cNXR NOB的传统观点,即仅仅是高亲和度的复制性生物.
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