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

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

PLOS ONE

PUBLIC LIBRARY SCIENCE

Año: 2023 vol. 18

1932-6203

The wax ester (WE) and triacylglycerol (TAG) biosynthetic potential of marine microorganismsis poorly understood at the microbial community level. The goal of this work was touncover the prevalence and diversity of bacteria with the potential to synthesize these neutrallipids in coastal sediments of two high latitude environments, and to characterize thegene clusters related to this process. Homolog sequences of the key enzyme, the wax estersynthase/acyl-CoA:diacylglycerol acyltransferase (WS/DGAT) were retrieved from 13 metagenomes,including subtidal and intertidal sediments of a Subantarctic environment(Ushuaia Bay, Argentina), and subtidal sediments of an Antarctic environment (Potter Cove,Antarctica). The abundance of WS/DGAT homolog sequences in the sediment metagenomeswas 1.23 ± 0.42 times the abundance of 12 single-copy genes encoding ribosomalproteins, higher than in seawater (0.13 ± 0.31 times in 338 metagenomes). Homologsequences were highly diverse, and were assigned to the Pseudomonadota, Actinomycetota,Bacteroidota and Acidobacteriota phyla. The genomic context of WS/DGAT homologsincluded sequences related to WE and TAG biosynthesis pathways, as well as to otherrelated pathways such as fatty-acid metabolism, suggesting carbon recycling might drivethe flux to neutral lipid synthesis. These results indicate the presence of abundant and taxonomically diverse bacterial populations with the potential to synthesize lipid storage compounds in marine sediments, relating this metabolic process to bacterial survival