Reconstructing Neutral-Lipids Metabolic Pathways of a Metagenomic Dataset from Ushuaia Bay Sediments

Abstract

Bacterial production of neutral lipids such as triacylglycerides, wax-esters and polyhydroxyalcanoates (TAG, WE and PHA-B, respectively) has been reported in Gammaproteobacteria and Actinobacteria. Within them, there is a short list of microorganisms with an in-depth study of the metabolic route involved in the synthesis of these compounds. To increase our knowledge of the potential of sediment bacteria in relation to this process, we analyzed homolog sequences of the key enzyme involved in TAG biosynthesis, the wax synthase/diacylglycerol acyltransferase (WS/DGAT), from a metagenomic dataset of a chronically-polluted Subantartic coastal environment, and their genomic context. Almost half of putative WS/DGAT sequences were related to those identified in genomes from members of the Actinobacteria phylum, mainly from the Acidimicrobiia, Actinobacteria and Nitriliruptoria classes, while 34% of the sequences shared higher identity values with WS/DGAT homologs from Proteobacteria (Gammaproteobacteria, followed by Alpha-, Beta- and Deltaproteobacteria).