identifier: traitmech:000111
label: cellulolysis
definition: A biopolymer-degradation metabolism in which an organism hydrolyzes cellulose
  to cellodextrins and glucose using cellulase systems, sometimes organized into cellulosomes.
definition_source: DOI:10.1128/MMBR.66.3.506-577.2002
trait_category: METABOLISM
term_kind: CLASS
mapping_status: REVIEWED
parent_traits:
- traitmech:000110
synonyms:
- synonym_text: cellulolytic
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1128/MMBR.66.3.506-577.2002
- synonym_text: cellulose degradation
  synonym_type: RELATED_SYNONYM
  source: DOI:10.1128/MMBR.66.3.506-577.2002
evidence:
- reference: DOI:10.1128/MMBR.66.3.506-577.2002
  notes: Lynd et al. review microbial cellulose utilization, its enzymology, and cellulosome
    systems.
- reference: DOI:10.1016/j.cbpa.2015.10.018
  notes: Cragg et al. place cellulose deconstruction within lignocellulose degradation
    across diverse organisms.
canonical_examples:
- taxon_id: NCBITaxon:1515
  taxon_label: Acetivibrio thermocellus
  note: "Thermophilic anaerobe secreting the paradigm cellulosome (formerly Clostridium thermocellum). Ruminococcus is the mesophilic rumen model."
  reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8951355/
causal_graphs:
- graph_id: cellulolysis_cellulase_systems
  title: Cellulolysis hydrolyzes cellulose to glucose
  description: Evidence-backed causal sketch linking cellulase systems (cellulosomes
    / free enzymes) to cellulose hydrolysis into cellodextrins and glucose.
  nodes:
  - node_id: cellulolysis_trait
    label: cellulolysis
    node_type: TRAIT
    grounding: traitmech:000111
    description: Hydrolysis of cellulose to assimilable sugars.
  - node_id: cellulase
    label: cellulase systems
    node_type: GENE_OR_PROTEIN
    description: Endoglucanases, exoglucanases, and beta-glucosidases (sometimes cellulosomal).
  - node_id: glucose
    label: glucose
    node_type: CHEMICAL
    description: Monomeric assimilable sugar released from cellulose.
    grounding: CHEBI:17234
  - node_id: cellulose
    label: cellulose
    node_type: CHEMICAL
    description: Beta-1,4-linked glucose polymer substrate.
    grounding: CHEBI:18246
  - node_id: endoglucanase
    label: endoglucanase
    node_type: GENE_OR_PROTEIN
    description: Cellulase that cleaves internal bonds of cellulose chains.
    grounding: UniProtKB:A0A060H8L4
  - node_id: cellobiohydrolase
    label: cellobiohydrolase / exoglucanase
    node_type: GENE_OR_PROTEIN
    description: Cellulase that processively releases cellobiose from chain ends.
  - node_id: beta_glucosidase
    label: beta-glucosidase
    node_type: GENE_OR_PROTEIN
    description: Enzyme hydrolyzing cellobiose to glucose.
    grounding: UniProtKB:A0A031JNC1
  - node_id: cellobiose
    label: cellobiose
    node_type: CHEMICAL
    description: Glucose disaccharide intermediate of cellulose hydrolysis.
  - node_id: cellulosome
    label: cellulosome
    node_type: CELLULAR_LOCALIZATION
    description: Multienzyme complex built on scaffoldins for cellulose degradation.
    grounding: GO:0043263
  - node_id: scaffoldin
    label: scaffoldin
    node_type: GENE_OR_PROTEIN
    description: Non-catalytic backbone protein of the cellulosome.
  - node_id: cohesin_domain
    label: cohesin domain
    node_type: GENE_OR_PROTEIN
    description: Scaffoldin module that binds dockerin domains.
    grounding: UniProtKB:A0A174EJP3
  - node_id: dockerin_domain
    label: dockerin domain
    node_type: GENE_OR_PROTEIN
    description: Enzyme-borne module that binds scaffoldin cohesin domains.
  - node_id: ccr
    label: carbon catabolite repression
    node_type: BIOLOGICAL_PROCESS
    description: Glucose-signal-driven repression of catabolic gene transcription.
  - node_id: cellulolytic_genes
    label: cellulolytic / lignocellulose-catabolic genes
    node_type: GENE_OR_PROTEIN
    description: Genes encoding cellulose-degrading enzymes.
  edges:
  - subject: cellulase
    predicate: enables
    object: cellulolysis_trait
    description: Cellulase systems hydrolyze cellulose extracellularly.
    evidence:
    - reference: DOI:10.1128/MMBR.66.3.506-577.2002
      notes: Lynd et al. review microbial cellulose utilization and the cellulase
        systems involved.
    predicate_id: RO:0002327
  - subject: cellulolysis_trait
    predicate: produces
    object: glucose
    description: Cellulose hydrolysis yields cellodextrins and glucose.
    evidence:
    - reference: DOI:10.1016/j.cbpa.2015.10.018
      notes: Cragg et al. place cellulose deconstruction within lignocellulose degradation.
    predicate_id: METPO:2000202
  - subject: endoglucanase
    predicate: degrades
    object: cellulose
    description: Endoglucanase participates in concerted hydrolysis of cellulose.
    evidence:
    - reference: DOI:10.1093/jambio/lxac002
      notes: Complete degradation of cellulose to glucose requires concerted action
        of cellobiohydrolases, endoglucanases and beta-glucosidases.
    predicate_id: METPO:2000007
  - subject: cellobiohydrolase
    predicate: degrades
    object: cellulose
    description: Cellobiohydrolase/exoglucanase participates in concerted hydrolysis
      of cellulose.
    evidence:
    - reference: DOI:10.1093/jambio/lxac002
      notes: Complete degradation of cellulose to glucose requires concerted action
        of cellobiohydrolases, endoglucanases and beta-glucosidases.
    predicate_id: METPO:2000007
  - subject: beta_glucosidase
    predicate: hydrolyzes
    object: cellobiose
    description: Beta-glucosidase hydrolyzes cellobiose in the downstream saccharification
      step.
    evidence:
    - reference: DOI:10.1186/s13568-023-01658-0
      notes: Beta-glucosidase activity converting cellobiose into glucose.
    predicate_id: METPO:2000013
  - subject: beta_glucosidase
    predicate: produces
    object: glucose
    description: Beta-glucosidase releases glucose from cellobiose.
    evidence:
    - reference: DOI:10.1186/s13568-023-01658-0
      notes: Beta-glucosidase activity converting cellobiose into glucose; product
        edge directly stated.
    predicate_id: METPO:2000202
  - subject: cellulosome
    predicate: has backbone component
    object: scaffoldin
    description: Cellulosomes are multienzyme complexes built on scaffoldins.
    evidence:
    - reference: DOI:10.1093/jambio/lxac002
      notes: They are multienzyme complexes built on scaffoldins.
  - subject: scaffoldin
    predicate: contains
    object: cohesin_domain
    description: Scaffoldins bear cohesin modules.
    evidence:
    - reference: DOI:10.3389/fmicb.2023.1288286
      notes: Scaffoldins are the non-catalytic backbone and bear modules called cohesin.
  - subject: dockerin_domain
    predicate: binds to
    object: cohesin_domain
    description: Dockerin-cohesin interaction assembles enzymes onto the scaffoldin.
    evidence:
    - reference: DOI:10.1093/jambio/lxac002
      notes: Dockerin modules interacting with scaffoldin cohesin modules; canonical
        assembly interaction.
  - subject: ccr
    predicate: represses
    object: cellulolytic_genes
    description: Carbon catabolite repression represses cellulolytic/lignocellulose-catabolic
      genes when glucose signals are high.
    evidence:
    - reference: DOI:10.1093/jambio/lxac002
      notes: CcpA recognizing CRE sites to prevent transcription of lignocellulose-catabolic
        genes when glucose-derived signals are high.
curation_history:
- timestamp: '2026-06-08T00:00:00Z'
  curator: claude
  action: PROPOSED_FROM_RESEARCH
  changes: Proposed candidate METABOLISM trait (cellulolysis); sub-variant of biopolymer
    degradation.
  llm_assisted: true
- timestamp: '2026-06-10T14:00:00Z'
  curator: claude
  action: CURATED_CAUSAL_GRAPH
  changes: Added evidence-backed causal graph (cellulase hydrolysis of cellulose)
    with RO/METPO predicate groundings; promoted PROPOSED to REVIEWED.
  llm_assisted: true
- timestamp: '2026-06-14T06:55:38Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 1 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:17234×1).
  llm_assisted: true
- timestamp: '2026-06-23T00:00:00Z'
  curator: claude
  action: ENRICH_CAUSAL_GRAPH
  changes: Added 8 evidence-backed generic edges (11 new nodes) from the deep-research
    report.
  llm_assisted: true
- timestamp: '2026-06-24T17:21:12Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 1 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000202×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:32Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 2 causal-node grounding field(s) via mappings/node_grounding.tsv
    (CHEBI:18246×1, GO:0043263×1).
  llm_assisted: true
- timestamp: '2026-06-24T17:23:38Z'
  curator: claude
  action: GROUND_CAUSAL_PREDICATES
  changes: Grounded 3 causal-edge predicate_id field(s) via mappings/predicate_grounding.tsv
    (METPO:2000007×2, METPO:2000013×1).
  llm_assisted: true
- timestamp: '2026-06-26T07:15:18Z'
  curator: claude
  action: GROUND_CAUSAL_NODES
  changes: Grounded 3 causal-node grounding field(s) via mappings/node_grounding.tsv
    (UniProtKB:A0A060H8L4×1, UniProtKB:A0A031JNC1×1, UniProtKB:A0A174EJP3×1).
  llm_assisted: true