乙酸盐对热友和友细菌的CO2固定通路的影响
Yoko Chiba1,2,3, Tomomi Sumida4, Masafumi Kameya5,6
1Center for Sustainable Resource Science, RIKEN, Wako, Saitama 351-0198, Japan.
ISME communications
|December 29, 2025
概括
乙酸盐的可用性可以抑制木-Ljungdahl路径在细菌中的二氧化碳固定. 这表明其在有机碳环境中的贡献可能被高估了,挑战了祖先的代谢模型.
科学领域:
- 微生物学 微生物学
- 生物化学 生物化学
- 地质化学 地质化学
背景情况:
- 伍德-格达尔 (Wood-Ljungdahl,简称WL) 路径和还原性三碳酸 (reductive tricarboxylic acid,简称rTCA) 循环是细菌在非热性生态系统中的关键二氧化碳固定路径.
- 这些通路在有可用的有机碳环境中的作用尚不清楚.
研究的目的:
- 研究细胞外酸盐对三种热友细菌的二氧化碳固定通路的影响.
- 确定酸盐可用性如何影响WL通路和rTCA循环的活性.
主要方法:
- 利用基于13C标记物的代谢学来分析碳同化.
- 检查了三种物种:热酸盐体指数,氧菌热和热菌氨基酸体.
- 在化学性自性和化学性异性 (补充乙酸盐) 条件下比较CO2固定.
主要成果:
- 乙抑制了T. indicus的WL途径二氧化碳固定,该途径主要使用乙作为碳来源.
- 热和T. ammonificans通过rTCA循环同化了二氧化碳和酸盐.
- 氨基主要使用rTCA循环固定二氧化碳,即使没有酸盐.
结论:
- 在富含乙的环境中,WL路径对二氧化碳固定的贡献可能被高估了.
- 在现存的微生物中,通过WL和rTCA途径同时固定二氧化碳是不有利的.
- rTCA循环是这些热友细菌中碳同化的一种多功能途径.
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