Extended Data Fig. 7: Glyoxylate assimilation pathways in marine metagenomes.
From: Marine Proteobacteria metabolize glycolate via the β-hydroxyaspartate cycle
a, Metagenomes collected during the Tara Oceans expedition were searched for the presence of BhcC as representative enzyme of the BHAC. Dots on the map mark sampling locations of metagenomes containing BhcC sequences; the colour of the dot corresponds to BhcC abundance in samples from surface water (0.22–3-µm size fraction), as shown in the legend. The map was made with Ocean Data View 5.1.5 (Schlitzer, R., Ocean Data View, odv.awi.de, 2018). b, Phylogenetic distribution of 104 unique BhcC sequences found in Tara Oceans metagenomes. c, Phylogenetic distribution of 32 unique Gcl (as representative enzyme of the glycerate pathway) sequences found in Tara Oceans metagenomes. Whereas BhcC is mainly found in Alphaproteobacteria, Gcl is largely restricted to Gammaproteobacteria. b, c, Taxonomy is based on GTDB64 (release 03-RS86; http://gtdb.ecogenomic.org/). d, Ratio of the abundances (in percentage of total reads) of BhcC to Gcl in Tara Oceans metagenomes. BhcC:Gcl ratios from n = 210 samples are plotted together (left) and clustered by sampling depth (SRF, upper layer zone (n = 101); DCM, deep chlorophyll maximum layer (n = 68); MES, mesopelagic zone (n = 41)). Samples from the 0.22–3-µm size fraction are denoted by a black dot; samples from the <0.22-µm size fraction are denoted by a blue dot. The median is shown in orange as centre value and error bars represent interquartile ranges. The median BhcC:Gcl ratio of all samples is 18.7. The highest BhcC:Gcl ratio is found in surface water samples (median = 41.8), with the ratio generally being higher in the 0.22–3-µm size fraction than in the <0.22-µm size fraction. Sequence IDs, abundances and BhcC:Gcl ratios are given in Supplementary Data 2.
