Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
Computational and Systems Biology Laboratory, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
Commun Biol. 2023 Mar 1;6(1):230. doi: 10.1038/s42003-023-04617-4.
A thermophilic, chemolithoautotrophic, and aerobic microbial consortium (termed carbonitroflex) growing in a nutrient-poor medium and an atmosphere containing N, O, CO, and CO is investigated as a model to expand our understanding of extreme biological systems. Here we show that the consortium is dominated by Carbonactinospora thermoautotrophica (strain StC), followed by Sphaerobacter thermophilus, Chelatococcus spp., and Geobacillus spp. Metagenomic analysis of the consortium reveals a mutual relationship among bacteria, with C. thermoautotrophica StC exhibiting carboxydotrophy and carbon-dioxide storage capacity. C. thermoautotrophica StC, Chelatococcus spp., and S. thermophilus harbor genes encoding CO dehydrogenase and formate oxidase. No pure cultures were obtained under the original growth conditions, indicating that a tightly regulated interactive metabolism might be required for group survival and growth in this extreme oligotrophic system. The breadwinner hypothesis is proposed to explain the metabolic flux model and highlight the vital role of C. thermoautotrophica StC (the sole keystone species and primary carbon producer) in the survival of all consortium members. Our data may contribute to the investigation of complex interactions in extreme environments, exemplifying the interconnections and dependency within microbial communities.
我们研究了一种嗜热、化能自养和需氧微生物共混物（称为碳硝杆菌），该共混物在营养贫乏的培养基中和含有 N、O、CO 和 CO 的大气中生长，以此作为模型来扩展我们对极端生物系统的理解。在这里，我们发现该共混物主要由嗜热碳氮菌（StC 株）主导，其次是嗜热球形菌、Chelatococcus 属和 Geobacillus 属。共混物的宏基因组分析揭示了细菌之间的相互关系，嗜热碳氮菌 StC 表现出羧化作用和二氧化碳储存能力。C. thermoautotrophica StC、Chelatococcus 属和 S. thermophilus 都携带有编码 CO 脱氢酶和甲酸盐氧化酶的基因。在原始生长条件下未获得纯培养物，表明在这种极端贫营养系统中，群体生存和生长可能需要严格调控的相互作用代谢。提出了面包师假说来解释代谢通量模型，并强调了嗜热碳氮菌 StC（唯一的关键物种和主要碳生产者）在所有共混物成员生存中的重要作用。我们的数据可能有助于对极端环境中复杂相互作用的研究，体现了微生物群落内部的相互联系和依存关系。
