Two-stage DF + microbial electrolysis (DF-MEC) biohydrogen

Provenanced sample report (Syntropa discovery, role-aware Stage-1). Corpus v0.2.2 (15,664 models, fingerprint 58a8f20e2aba) · tools v0.1.1 (git 44a8422, code a412618fd214) · env py3.13.13 win32 swiglpk5.0.13+osqp1.1.3+highspy1.15.1+pyscipopt6.2.1+optlang1.9.1 (deps 7f138ead8863). Feed=None target=None mode=produce. Report id 59dfba4153da (content-addressed to config + EXACT corpus + EXACT tools -> auditable; git-reproducibility is PENDING a committed + tagged tool release). Every claim here is computed; every drop reason and known limit is listed below.

Verdict: NOT-EXPRESSIBLE

GAP TYPE = outside FBA scope (the deliverable is not a secreted metabolite: electrode current, cell-free enzymatic depolymerization, or biomass). The DEFINING second stage (microbial electrolysis / electrohydrogenesis) requires an electrode/anode electron-acceptor for exoelectrogen extracellular electron transfer, and NO such species exists in the corpus vocab (grep electr|electrode|electron|anode|cathode|current returns 0 rows). The cathodic H2 is electrochemical, produced by applied voltage (~0.6-1.1 V), not a metabolic product. Collapsing to only the biological DF stage would silently duplicate candidate 36 (glucose->hydrogen) and misrepresent the two-stage system. MARKET DEMAND: Funded-program/TEA framing: modeled DF-MEC biohydrogen at ~$29-30/kg for solid food waste at 20 A/m2, falling to ~$5-6/kg only if current density reaches a hard-to-sustain 100 A/m2; payer is tipping fee + H2 sale + 45V credit, capex dominated by electrode area. A techno-economic feasibility projection, not procurement demand.

Caveats (disclosed up front)

• PRODUCTION IS AN OPEN-MEDIUM UPPER BOUND, NOT A YIELD. The production flux is FBA on an OPEN medium: carbon and reductant may enter from the background medium, not only the named feed: so a value CAN EXCEED the feed-limited stoichiometric ceiling (e.g. CO2+H2->acetate <=~5 at 4 H2/acetate; glucose->CH4 <=~1 per glucose by the hydrogenotrophic route). Read every production number as an unconstrained UPPER BOUND; a value above the ceiling is an open-medium artifact, not an achievable closed-medium yield. Closed-medium re-runs are Phase-2.
• FBA proves a route is stoichiometrically POSSIBLE, not that a living cell will do it.
• Every consortium here is a HYPOTHESIS until cultured; nothing is wet-lab validated.
• MEMBER IDENTITY IS A LEAD, NOT A CLAIM. Named members are FBA-feasible only in AUTOMATED, GAP-FILLED DRAFT reconstructions: gap-filling can add transporters/reactions an organism does not actually have, so a named member may CONTRADICT established physiology (a strain the literature does not know to perform this chemistry). Check each named organism against the literature before treating it as a real candidate; the value here is the metabolic PATTERN, not the specific strain.
• Feedstock-dependence is the anti-medium-artifact control: withdraw the feed and the product must collapse (a NOT-feedstock-dependent result is flagged SUSPECT, not a discovery).
• The ranking score is a documented heuristic for human review, not a truth or biology claim.
• Stage-1 selects finisher x diverse front-ends; multi-finisher relays are out of scope. Stage-2 expansion of winners is pending: these are PRELIMINARY until it runs.