High wax ester and triacylglycerol biosynthesis potential in coastal sediments of Antarctic and Subantarctic environments

VIRGINIA GALVÁN, FEDERICO PASCUTTI, NATALIA E. SANDOVAL, MARIANA P. LANFRANCONI, MARIANA LOZADA, ANA L. ARABOLAZA, WALTER P. MAC CORMACK, HÉCTOR M. ALVAREZ HUGO C. GRAMAJO & HEBE M. DIONISI

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2023

1932-6203

The wax ester (WE) and triacylglycerol (TAG)biosynthetic potential of marine microorganisms is poorly understood at themicrobial community level. The goal of this work was to uncover the prevalenceand diversity of bacteria with the potential to synthesize these neutral lipidsin coastal sediments of two high latitude environments, and to characterize thegene clusters related to this process. Homolog sequences of the key enzyme, thewax ester synthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) wereretrieved from 13 metagenomes, including subtidal and intertidal sediments of aSubantarctic environment (Ushuaia Bay, Argentina), and subtidal sediments of anAntarctic environment (Potter Cove, Antarctica). The abundance of WS/DGAThomolog sequences in the sediment metagenomes was 1.23 ± 0.42 times theabundance of 12 single-copy genes encoding ribosomal proteins, higher than inseawater (0.13 ± 0.31 times in 338 metagenomes). Homolog sequences were highlydiverse, and were assigned to the Proteobacteria, Actinobacteria, Bacteroidetesand Acidobacteria phyla. The genomic context of WS/DGAT homologs included sequencesrelated to WE and TAG biosynthesis pathways, as well as to other related pathwayssuch as fatty-acid metabolism, suggesting carbon recycling might drive the fluxto neutral lipid synthesis. These results indicate the presence of abundant andtaxonomically diverse bacterial populations with the potential to synthesizelipid storage compounds in marine sediments, relating this metabolic process tobacterial survival.