What this entity is
SSO is the groundwater and field-occurrence dataset used in the ENIGMA Carbon Census. 1
- Canonical name: SSO. 1
- Known aliases: SSO. 1
- Stable external identifier: None was reported in the source document. 1
Key facts from the ENIGMA Carbon Census
SSO supplied 59 of the 83 enrichment compounds analyzed in the census, with the remaining 24 compounds coming from necromass. 1
The census detected 62 implicated utilizer genera in the SSO field atlas at genus resolution. 1
Top field prevalences in the SSO atlas were approximately 0.7–0.9, and utilizers associated with 3-hydroxybenzoic acid reached a field prevalence of 0.90. 1
The SSO field atlas provided occurrence context for predicted utilizers, but it did not measure compound degradation or catabolic activity. 1
The ENIGMA Carbon Census could not statistically test groundwater-versus-necromass source tracking because only 2 of the 8 ENIGMA-isolate-callable compounds were necromass-sourced, and both were phthalate-class aromatics. 1
Subsurface community ecology
The SSO ecology analysis refines the field-atlas occurrence context with 16S amplicon sequencing across 9 wells in a 3×3 grid spanning approximately 6 m, where sediment communities comprised 23,458 ASVs and showed significant distance-decay (Mantel Spearman ρ = 0.323, p = 0.029). 2 Hydrogeological zone explained 27.5% of sediment community variance (PERMANOVA F = 4.05, p = 0.0001), while well identity explained 19.2% and was not significant (F = 0.80, p = 0.979), supporting an environment-linked interpretation of SSO community structure. 2
Groundwater and sediment communities from the same wells differed substantially (median Bray–Curtis dissimilarity = 0.424), with groundwater enriched in Rhodanobacter, Gallionella, and Sideroxydans and sediment enriched in Anaeromyxobacter, Arcobacter, and Ca. Methanoperedens. 2 Groundwater community rankings remained nearly unchanged over 9 days (Mantel ρ = 0.867, p = 0.001), but the sediment–groundwater comparison is confounded by an 18-month sampling offset. 2
The proposed northeast-to-southwest contamination plume and inferred redox gradients are hypotheses, not direct measurements: 221 SSO geochemistry sample tubes are registered in CORAL, but the relevant measurements were not loaded. 2 This qualifies any interpretation linking SSO occurrence patterns to contamination or catabolic activity. 2
The MicrobeAtlas metal-ecology analysis supports using SSO well data as environmental occurrence context: across 133 samples, community-weighted mean metal-type diversity differed among 8 wells (Kruskal–Wallis H = 29.10, p = 0.0001), increased with time point (Spearman ρ = +0.383, p < 0.0001), and increased within FW216 (ρ = +0.576, p = 0.0001). 3 However, Sulfurimonas abundance decreased with time (ρ = −0.323, p = 0.0002), qualifying any inference that changing community composition was generally driven by metal resistance rather than electron-acceptor availability. 3 Only 16.8% of reads were joinable to genus-level GTDB metal-diversity data, so these community-weighted values require coverage-bias diagnostics. 3
SSO-related findings are summarized in ENIGMA Carbon Census — Tiered Knowledge Census of 83 Enrichment Compounds, SSO Subsurface Community Ecology — Spatial Structure, Functional Gradients, and Hydrogeological Drivers, and Metal Resistance Ecology — Phylogenetic Conservation vs. Environmental Selection and contribute to ecotype-environment-gene-content, cross-tenant-data-bridging, environmental-resistome, and multi-omics-integration. 1,2,3