掲載種別：研究論文（学術雑誌）   出版者・発行元：American Chemical Society (ACS)  

DOI： 10.1021/jacs.5c01948

researchmap

担当区分：最終著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Microbiology Research Foundation  

DOI： 10.2323/jgam.2025.04.003

researchmap

掲載種別：研究論文（学術雑誌）  

DOI： 10.1021/acsearthspacechem.4c00314

researchmap

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

Circumneutral iron-rich hot springs may represent analogues of Neoarchean to Paleoproterozoic oceans of early Earth, potentially providing windows into ancient microbial ecology. Here we sampled five Japanese hot springs to gain insights into functional processes and taxonomic diversity in these analog environments. Amplicon and metagenomic sequencing confirm a hypothesis where taxonomy is distinct between sites and linked to the geochemical setting. Metabolic functions shared among the springs include carbon fixation via the reductive pentose phosphate cycle, nitrogen fixation, and dissimilatory iron oxidation/reduction. Among the sites, Kowakubi was unique in that it was dominated by Hydrogenophilaceae, a group known for performing hydrogen oxidation, motivating a hypothesis that H2 as an electron donor may shape community composition even in the presence of abundant ferrous iron. Evidence for nitrogen cycling across the springs included N2 fixation, dissimilatory nitrate reduction to ammonia (DNRA), and denitrification. The low-salinity springs Furutobe and OHK lacked evidence for ammonium oxidation by ammonia monooxygenase, but evidence for complete nitrification existed at Kowakubi, Jinata, and Tsubakiyama. In most sites, the microaerophilic iron-oxidizing bacteria from the Zetaproteobacteria or Gammaproteobacteria classes had higher relative abundances than Cyanobacteria. Microaerophilic iron oxidizers may outcompete abiotic Fe oxidation, while being fueled by oxy-phototrophic Cyanobacteria. Our data provide a foundation for considering which factors may have controlled productivity and elemental cycling as Earth's oceans became oxygenated at the onset of the Great Oxidation Event.

DOI： 10.1264/jsme2.ME24067

PubMed

researchmap

出版者・発行元：arXiv  

We derive a single-cell level understanding of metabolism in an isogenic cyanobacterial population by integrating secondary ion mass spectrometry (SIMS) derived multi-isotope uptake measurements of Synechocystis sp. PCC6803 with a statistical inference protocol based on Liebig's law of the minimum, the maximum entropy principle, and constraint-based modeling. We find the population is structured in two metabolically distinct clusters: cells optimizing carbon yield while excessively turning over nitrogen, and cells which act reciprocally, optimizing nitrogen yield and excessively turning over carbon. This partition enables partial heterotrophy within the population via metabolic exchange, likely in the form of organic acids. Exchange increases the feasible metabolic space, and mixotrophic cells achieve the fastest growth rates. Metabolic flux analysis at the single-cell level reveals heterogeneity in carbon fixation rates, Rubisco specificity, and nitrogen assimilation. Our results provide a necessary foundation for understanding how population level phenotypes arise from the collective contributions of distinct individuals.

DOI： 10.48550/ARXIV.2506.05916

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

会議種別：口頭発表（招待・特別）  

researchmap

researchmap

researchmap

researchmap

researchmap