Energy efficiency and biological interactions define the core microbiome of deep oligotrophic groundwater Mehrshad, Maliheh López Fernández, Margarita The work conducted by the U.S. Department of Energy Joint Genome Institute, a DOE Office of Science User Facility, is supported under Contract No. DE-AC02-05CH11231. The Swedish Research Council (contracts 2018-04311, 2017-04422, and 2014-4398) and The Swedish Nuclear Fuel and Waste Management Company (SKB) supported the study. M.D. thanks the Crafoord Foundation (contracts 20180599 and 20130557), the Nova Center for University Studies, Research and Development, and Familjen Hellmans Stiftelse for financial support. M.D. and D.S. thank the Carl Tryggers Foundation (grant KF16: 18) for financial support. S.B. and M.M. acknowledge financial support from the Swedish Research Council and Science for Life Laboratory. High-throughput sequencing was also carried out at the National Genomics Infrastructure hosted by the Science for Life Laboratory. Bioinformatics analyses were carried out utilizing the Uppsala Multidisciplinary Center for Advanced Computational Science (UPPMAX) at Uppsala University (projects b2013127, SNIC 2019/3-22, and SNIC 2020/5-19) with support from a SciLifeLab-WABI bioinformatics grant. We would also like to thank Mats Astrom for his comments on the Aspo HRL lithology. JS is financially supported by the Knut and Alice Wallenberg Foundation as part of the National Bioinformatics Infrastructure Sweden at SciLifeLab. While oligotrophic deep groundwaters host active microbes attuned to the low-end of the bioenergetics spectrum, the ecological constraints on microbial niches in these ecosystems and their consequences for microbiome convergence are unknown. Here, we provide a genome-resolved, integrated omics analysis comparing archaeal and bacterial communities in disconnected fracture fluids of the Fennoscandian Shield in Europe. Leveraging a dataset that combines metagenomes, single cell genomes, and metatranscriptomes, we show that groundwaters flowing in similar lithologies offer fixed niches that are occupied by a common core microbiome. Functional expression analysis highlights that these deep groundwater ecosystems foster diverse, yet cooperative communities adapted to this setting. We suggest that these communities stimulate cooperation by expression of functions related to ecological traits, such as aggregate or biofilm formation, while alleviating the burden on microorganisms producing compounds or functions that provide a collective benefit by facilitating reciprocal promiscuous metabolic partnerships with other members of the community. We hypothesize that an episodic lifestyle enabled by reversible bacteriostatic functions ensures the subsistence of the oligotrophic deep groundwater microbiome. 2021-09-21T06:36:59Z 2021-09-21T06:36:59Z 2021-07-12 journal article Mehrshad, M... [et al.]. Energy efficiency and biological interactions define the core microbiome of deep oligotrophic groundwater. Nat Commun 12, 4253 (2021). [https://doi.org/10.1038/s41467-021-24549-z] http://hdl.handle.net/10481/70308 10.1038/s41467-021-24549-z eng http://creativecommons.org/licenses/by/3.0/es/ open access Atribución 3.0 España Nature