diff --git a/data/traits/morphology/capsule.yaml b/data/traits/morphology/capsule.yaml
index be4f5b01..a6df4117 100644
--- a/data/traits/morphology/capsule.yaml
+++ b/data/traits/morphology/capsule.yaml
@@ -50,6 +50,16 @@ causal_graphs:
node_type: QUALITY
description: Reduced recognition and clearance by host innate immunity.
edges:
+ - subject: capsule_assembly
+ predicate: produces
+ object: capsular_polysaccharide
+ description: Capsule biosynthesis synthesizes and exports the high-MW capsular
+ polysaccharide.
+ evidence:
+ - reference: DOI:10.1146/annurev.biochem.75.103004.142545
+ notes: Whitfield reviews biosynthesis, export, and surface assembly of the
+ capsular polysaccharide polymer.
+ predicate_id: biolink:produces
- subject: capsule_assembly
predicate: enables
object: capsule_trait
@@ -86,3 +96,9 @@ curation_history:
changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
(CHEBI:3379×1).
llm_assisted: true
+- timestamp: '2026-06-16T00:00:00Z'
+ curator: claude
+ action: FIX_ORPHAN_NODE
+ changes: Connected the previously-orphaned capsular_polysaccharide node via a
+ 'produces' (biolink:produces) edge from capsule_assembly.
+ llm_assisted: true
diff --git a/data/traits/physiology/urease_activity.yaml b/data/traits/physiology/urease_activity.yaml
index c83c9e15..0c862fd1 100644
--- a/data/traits/physiology/urease_activity.yaml
+++ b/data/traits/physiology/urease_activity.yaml
@@ -75,6 +75,16 @@ causal_graphs:
- reference: DOI:10.1128/mr.53.1.85-108.1989
notes: Mobley & Hausinger support ammonia release from urea hydrolysis.
predicate_id: METPO:2000202
+ - subject: urease_function
+ predicate: manifests as
+ object: urease_activity_trait
+ description: Urease enzymatic activity manifests as the observable urease-activity
+ phenotype scored by the diagnostic urease test.
+ evidence:
+ - reference: DOI:10.1128/mr.59.3.451-480.1995
+ notes: Urease activity (urea-to-ammonia hydrolysis raising local pH) is the
+ assayable phenotype used to score urease-positive organisms.
+ predicate_id: METPO:2007400
curation_history:
- timestamp: '2026-06-04T00:00:00Z'
curator: claude
@@ -95,3 +105,10 @@ curation_history:
changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
(UniProtKB:A0A090IGX8×1).
llm_assisted: true
+- timestamp: '2026-06-16T00:00:00Z'
+ curator: claude
+ action: FIX_ORPHAN_NODE
+ changes: Connected the previously-orphaned urease_activity_trait node via a
+ 'manifests as' (METPO:2007400) edge from urease_function, so the molecular
+ function links to the observable trait.
+ llm_assisted: true
diff --git a/justfile b/justfile
index 74af2b06..1c0478f6 100644
--- a/justfile
+++ b/justfile
@@ -48,6 +48,12 @@ audit-writers *args:
audit-proposals *args:
uv run python scripts/audit_proposals.py {{args}}
+# Structural-integrity audit of causal graphs: flag dangling edges (subject/
+# object not a declared node) and orphan nodes (declared but unreferenced).
+# Emits reports/causal_graph_audit.tsv; exits 1 on any defect.
+audit-graphs *args:
+ uv run python scripts/audit_causal_graphs.py {{args}}
+
# Verify a METPO ROBOT-template proposal cohort under proposals/.
# Runs column-count, header, parent integrity, subset tag, and scope-A/C
# coverage checks. See .claude/skills/metpo-proposal/SKILL.md.
@@ -170,7 +176,7 @@ check: lint test
# Composite QC: strict closed-schema validation + schema-quality probes +
# writers audit + proposal citation bar. Mirrors the qc target in
# MediaIngredientMech / CultureMech.
-qc: validate-strict audit-schema audit-writers audit-proposals
+qc: validate-strict audit-schema audit-writers audit-proposals audit-graphs
# --- id↔label correspondence gate (vendored byte-identical across the Mech repos) ---
diff --git a/pages/category/ecology.html b/pages/category/ecology.html
index da2a6c75..7da34897 100644
--- a/pages/category/ecology.html
+++ b/pages/category/ecology.html
@@ -244,7 +244,7 @@ ECOLOGY (26)