錳氧化引起細菌化學自養
作者:
小柯機器人發布時間:2020/7/16 17:17:25
美國加州理工學院Jared R. Leadbetter團隊提出錳氧化能夠引起細菌化學自養。這一研究成果於2020年7月15日發表在《自然》上。
他們提煉出一種富集培養,該培養表現出依賴於Mn(II)氧化的指數增長到兩種微生物物種的共培養。氧化需要在允許的溫度下使細菌存活,從而導致與細胞相關的氧化錳小結節的產生。該培養物的主要成員(他們將其命名為「 Candidatus Manganitrophus noduliformans」)隸屬於硝化螺菌門(也稱為硝化螺菌),但與已知的硝化螺菌和鉤端螺旋體關係較遠。
他們分離出少數菌種,即一種不會單獨氧化Mn(II)的β變形桿菌,並將其命名為石綠假單胞菌。穩定同位素探測顯示13CO2固定到細胞生物質中,這依賴於Mn(II)的氧化。轉錄組學分析揭示了將細胞外錳氧化與有氧能量守恆和自養二氧化碳固定結合的候選途徑。這些發現擴展了已知的供給生命的無機代謝多樣性,並完成了錳的生物地球化學能循環,該循環可能與其他主要的全球元素循環有關。
研究人員表示,錳是地球上最豐富的元素之一。長期以來,理論上已經有人對錳的氧化進行了理論研究(尚未證明),以促進化學自養微生物的生長。
附:英文原文
Title: Bacterial chemolithoautotrophy via manganese oxidation
Author: Hang Yu, Jared R. Leadbetter
Issue&Volume: 2020-07-15
Abstract: Manganese is one of the most abundant elements on Earth. The oxidation of manganese has long been theorized1—yet has not been demonstrated2,3,4—to fuel the growth of chemolithoautotrophic microorganisms. Here we refine an enrichment culture that exhibits exponential growth dependent on Mn(II) oxidation to a co-culture of two microbial species. Oxidation required viable bacteria at permissive temperatures, which resulted in the generation of small nodules of manganese oxide with which the cells associated. The majority member of the culture—which we designate 『Candidatus Manganitrophus noduliformans』—is affiliated to the phylum Nitrospirae (also known as Nitrospirota), but is distantly related to known species of Nitrospira and Leptospirillum. We isolated the minority member, a betaproteobacterium that does not oxidize Mn(II) alone, and designate it Ramlibacter lithotrophicus. Stable-isotope probing revealed 13CO2 fixation into cellular biomass that was dependent upon Mn(II) oxidation. Transcriptomic analysis revealed candidate pathways for coupling extracellular manganese oxidation to aerobic energy conservation and autotrophic CO2 fixation. These findings expand the known diversity of inorganic metabolisms that support life, and complete a biogeochemical energy cycle for manganese5,6 that may interface with other major global elemental cycles.
DOI: 10.1038/s41586-020-2468-5
Source: https://www.nature.com/articles/s41586-020-2468-5