RT Journal Article
SR Electronic
T1 Gulf of Mexico blue hole harbors high levels of novel microbial lineages
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.10.18.342550
DO 10.1101/2020.10.18.342550
A1 NV Patin
A1 ZA Dietrich
A1 A Stancil
A1 M Quinan
A1 JS Beckler
A1 ER Hall
A1 J Culter
A1 CG Smith
A1 M Taillefert
A1 FJ Stewart
YR 2020
UL http://biorxiv.org/content/early/2020/10/19/2020.10.18.342550.abstract
AB Exploration of oxygen-depleted marine environments has consistently revealed novel microbial taxa and metabolic capabilities that expand our understanding of microbial evolution and ecology. Marine blue holes are shallow karst formations characterized by low oxygen and high organic matter content. They are logistically challenging to sample, and thus our understanding of their biogeochemistry and microbial ecology is limited. We present a metagenomic characterization of Amberjack Hole on the Florida continental shelf (Gulf of Mexico). Dissolved oxygen became depleted at the hole’s rim (32 m water depth), remained low but detectable in an intermediate hypoxic zone (40-75 m), and then increased to a secondary peak before falling below detection in the bottom layer (80-110 m), concomitant with increases in nutrients, dissolved iron, and a series of sequentially more reduced sulfur species. Microbial communities in the bottom layer contained heretofore undocumented levels of the recently discovered phylum Woesearchaeota (up to 58% of the community), along with lineages in the bacterial Candidate Phyla Radiation (CPR). Thirty-one high-quality metagenome-assembled genomes (MAGs) showed extensive biochemical capabilities for sulfur and nitrogen cycling, as well as for resisting and respiring arsenic. One uncharacterized gene associated with a CPR lineage differentiated hypoxic from anoxic zone communities. Overall, microbial communities and geochemical profiles were stable across two sampling dates in the spring and fall of 2019. The blue hole habitat is a natural marine laboratory that provides opportunities for sampling taxa with under-characterized but potentially important roles in redox-stratified microbial processes.Competing Interest StatementThe authors have declared no competing interest.