Fig 1.
Light microscopy images of members of the Beggiatoaceae observed onboard the R/V mirabilis, offshore Namibia.
A. Filamentous Beggiatoaceae often morphologically identified as “Beggiatoa”, B. Filamentous Beggiatoaceae often morphologically identified as “Thioploca”, C. Non-filamentous Beggiatoaceae often morphologically identified as “Thiomargarita”. Scale bars in A and B are 150 um, and C in 600 um.
Fig 2.
Map of sampling stations off the coast of Namibia, Africa.
The sampling sites in this study were Marine Station 23002 (-22.999967, 14.3708), depth 36.4 m; Station 23020 (-23.00125, 14.04775), depth 125 m; Station 20020 (-20.002283, 12.67975), depth 85.8 m; and Station Geochem2_1 (-24.050,733, 14.250233), depth 118 m. The baseline map was reproduced from the GEBCO world map 2021, www.gebco.net.
Fig 3.
Geochemical profiles for the top 10 cm of sediment core porewaters with general zonation of Beggiatoaceae.
Porewaters were collected from marine stations 23002 (blue; 1–10 cm), 23020 (orange; 1–7, 9–10 cm) and 20020 (grey; 1–7 cm). Formate (<11 μM) and nitrite (<2 μM) and other data points not shown for analyzed 1cm horizons were below detection limits. Standard deviations were low and representative crossbars were not visible on plots.
Fig 4.
Principal coordinate analysis of 16S rRNA communities of samples collected from four marine stations: 23002, 20020, 23020 and Geochem2_1 and at depths between 0–5 cm.
The plot was generated using multidimensional scaling with Euclidean distancing.
Fig 5.
Box plots of the phyla of ASVs by percent community composition by A. depth in cm. B. sample type. C. location.
Fig 6.
Modified Venn diagram of 123 ASVs detected by DESeq2 as having a statistically significant association with non-filamentous Beggiatoaceae hosts from Marine Station Geochem2_1 and Marine Station 23020.
ASVs represented in both circles were found to have a significant association with the hosts from both stations. ASVs neighboring the overlapping circles, we determined likely also were significantly enriched the other station but a single low representative inhibited detection via DESeq2. ASVs represented by large circles appeared to also be enriched in the sample from shallow station 23002.