Identification of novel enolase negative Segatella copri subspecies supports notion of Segatella copri speciation via alternative phosphoenolpyruvate synthesis pathways

Abstract

BackgroundSegatella copri is characterised as a prominent glycolytic plant-based fiber utiliser within the human gut. My recent work has introduced a new interpretation of the positive impacts of plant-based polysaccharides on S. copri, as a significant negative relationship between S. copri and Blautia spp. was identified. The high rate of electron donor consumption by Blautia spp. indicated that competition for the electron donors, formate, ferredoxin and fumarate, could be the route of the negative relationship but would also explain the positive relationship with plant-based polysaccharides, as they are products of fiber fermentation intestinally. MethodsForty two genomes of S. copri were annotated via Prokka to identify alternative PEP pathways. Phylogenetics allowed effectively classification of the S. copri isolates into species and subspecies clusters. The sequence homology of nucleotides and proteins were analysed against the control, S. copri DSM 18205, to determine the level of conservation in the alternative phosphoenolpyruvate synthesis pathways. ResultsEnolase (eno) was not identified in the S. copri strains; JCM 13468, LKV-178-WT-2C, RHA03, RHA01 and RHA02, and the whole genome phylogenetic grouping of these strains, has proposed the existence of an eno(-) subspecies of S. copri. This work furthered this idea by identifying alternative PEP pathways from formate, ferredoxin and fumarate, which were the most conserved in the eno(-) S. copri genomes. ConclusionThis work has provided rationale to why enolase may not be present within the eno(-) S. copri isolates and have shown that these alternative PEP synthesis pathways could negate the requirement of enolase in cells and may be factor in evolution of S. copri metabolism.