@article{Chandola2022.08.25.505241,

title = {Combined in vivo and in situ genome-resolved metagenomics reveals novel symbiotic nitrogen fixing interactions between non-cyanobacterial diazotrophs and microalgae},

author = {Udita Chandola and Camille Trottier and Marinna Gaudin and Erik Manirakiza and Samuel Menicot and Isabelle Louvet and Thomas Lacour and Timothée Chaumier and Atsuko Tanaka and Samuel Chaffron and Leila Tirichine},

url = {https://www.biorxiv.org/content/early/2022/08/25/2022.08.25.505241},

doi = {10.1101/2022.08.25.505241},

year  = {2022},

date = {2022-08-25},

urldate = {2022-08-25},

journal = {bioRxiv},

publisher = {Cold Spring Harbor Laboratory},

abstract = {Non-cyanobacteria diazotrophs (NCDs) were shown to dominate in surface waters shifting the long-held paradigm of cyanobacteria dominance and raising fundamental questions on how these putative heterotrophic bacteria thrive in sunlit oceans. Here, we report an unprecedented finding in the widely used model diatom Phaeodactylum triconrnutum (Pt) of NCDs sustaining diatom cells in the absence of bioavailable nitrogen. We identified PtNCDs using metagenomics sequencing and detected nitrogenase gene in silico and/or by PCR. We demonstrated nitrogen fixation in PtNCDs and their close genetic affiliation with NCDs from the environment. We showed the wide occurrence of this type of symbiosis with the isolation of NCDs from other microalgae and their identification in the environment and in co-occurrence with photosynthetic microalgae. Overall, this study provides evidence for a previously overlooked symbiosis using a multidisciplinary model-based approach which will consequently help understand the different players driving global marine nitrogen fixation.Competing Interest StatementThe authors have declared no competing interest.},

keywords = {},

pubstate = {forthcoming},

tppubtype = {article}

}