Correct syngas alcohol graph direction, mechanistic certainty and acid-base grounding #1332

Finding

Source-based self-adversarial review of CommunityMech:000202 against PMID:27877166 finds a reversed/implied product-donation claim on the alcohol node, excessive mechanistic certainty, and process competition mislabeled as reciprocal ecological harm.

The C. kluyveri-to-C. ljungdahlii direction denotes proposed carboxylate supply, not ethanol donation in that direction. Alcohols are community products; their detection does not demonstrate donation from C. ljungdahlii to C. kluyveri. The paper regards C. ljungdahlii reduction as most likely, not selectively proven. Two-thirds ethanol utilization is a stoichiometric estimate, not traced flux. The pH comparisons come from phases of one reactor with feed changes and operational disturbances, not independent replicated pH treatments.

The graph names butyrate and hexanoate but grounds them to protonated acids. ChEBI identifies butyrate as CHEBI:17968 and hexanoate as CHEBI:17120. Keep pH-dependent acid/base speciation distinct from the named pool.

Acceptance

Preserve both existing metabolic arrows with correct directions and uncertainty. Make alcohol output and pH response community-level, not invented directed cross-feeding or COMPETITION (-/-). Preserve products, observed pH range and single-run limitations; correct the four graph chemical groundings. Add gap/history/ledger/tests and regenerate the page. No new nodes/arrows; retain canonical member IDs.

Whole record and full primary Introduction, Methods, Results, Discussion, two tables and five figure captions read; images not visually inspected. Deduplication covered 669 all-state issue titles/bodies plus ignored/hidden local files. #1319/#1321 concern different acetogen pairings and #529 concerns cultivation provenance, not this graph defect. Comments not exhaustive.