identifier: traitmech:000695
label: lethal algicidal activity
definition: A physiological capability of a microorganism to kill cells of eukaryotic
  algae or cyanobacteria.
definition_source: DOI:10.1128/AEM.66.10.4334-4339.2000
trait_category: PHYSIOLOGY
term_kind: CLASS
mapping_status: PROPOSED
parent_traits:
- METPO:1000059
evidence:
- reference: DOI:10.1128/AEM.64.8.2806-2813.1998
  snippet: All G. catenatum cells in strain Y-treated wells were dead and most cells
    had lysed after 2 days.
  notes: Lovejoy et al. 1998, PMID:9687434, PMC106776, Results sec9. Scientific Abstract,
    algal-culture/toxicity Methods, activity and specificity Results, Discussion,
    Tables 1/2/4/5 and actual Figure 2 inspected. Other actual figures and remaining
    Methods unread. Strain Y and filtrate support killing, unlike reversible ecdysis
    or rounding in other targets. Some dinoflagellate controls also died in separate
    experiments; raphidophyte controls remained healthy. P. carrageenovora was not
    uniformly harmless. Close affinity to P. peptidysin is not exact species identification.
    EXT_ID:9687434 AND SRC:MED matched source, ID, title and DOI on 2026-10-11. Full-text
    quotation directly matched; abstract matching alone cannot verify this passage.
- reference: DOI:10.1128/AEM.66.10.4334-4339.2000
  snippet: The marine bacterium Pseudoalteromonas sp. strain A28 was able to kill
    the diatom Skeletonema costatum strain NIES-324.
  notes: Lee et al. 2000, PMID:11010878, PMC92304, scientific Abstract. Abstract,
    Introduction, Methods, Results, Discussion, Tables 1/2 and actual Figures 1/2
    inspected; actual Figures 3/4 unread. Parental A28 culture and supernatant support
    the capability. Results sec11 reports no regrowth after transfer from cleared
    agar, distinguishing algicidal from algistatic, but that experiment is data not
    shown. Protease II lacked algicidal action despite protease activity. Six N-terminal
    residues do not establish full AprI identity; NH1/NH2 are mutagenized derivatives,
    not natural exemplars. A separate group from Lovejoy et al., not a replication
    of strain Y. EXT_ID:11010878 AND SRC:MED matched source, ID, title and DOI on
    2026-10-11; quotation matched direct scientific Abstract and qualified API abstract.
- reference: DOI:10.3390/toxins15030220
  snippet: The cyanobacterial cell walls were severely damaged, leading to the leakage
    of intracellular components.
  notes: 'Zhang et al. 2023, PMID:36977111, PMC10058357, Results 2.4. Scientific Abstract,
    Introduction, Results 2.1-2.4, Discussion, Methods 5.1-5.4/5.8/5.12 and actual
    Figure 3 with caption inspected; other figures and supplement unread. Filtrate
    damage/lysis supports cyanobacterial target scope. Methods 5.3 calculates relative
    cell-density reduction versus controls, not a direct dead-cell fraction; no percentage
    is adopted. Results 2.1 calls HY #320 from 411 isolates, versus #332/412 in Methods
    5.2 and #332 in Figure 1 caption; provenance remains unreconciled. Molecular agents
    are unidentified; transcription changes alone do not establish causal protein
    edges. EXT_ID:36977111 AND SRC:MED matched source, ID, title and DOI on 2026-10-11.
    Quotation directly matched full text.'
discussions:
- discussion_id: lethal-algicidal-scope-and-mappings
  prompt: Resolve mappings while retaining a lethal endpoint and actor-level scope.
  kind: CURATION_TODO
  status: OPEN
  rationale: The lethal qualifier distinguishes this capability from broader algicidal
    usage. Paul and Pohnert 2011, DOI:10.1371/journal.pone.0021032, Methods Monitoring
    algicidal activity and Results, uses fluorescence-based growth inhibition as an
    algicidal readout; those directly read passages provide terminology context, not
    additional killing evidence. This record requires killing, not reduced fluorescence,
    reversible growth arrest, ecdysis, passive removal or a protease sequence alone.
    It denotes the acting microbe's capability, not an algicide molecule, treated
    alga's susceptibility or assay row. Cyanobacteria are included explicitly, not
    classified as eukaryotic algae. Activity against some susceptible targets suffices;
    universal host range is not asserted. Predatory bacterium traitmech:000054 requires
    killing and consuming bacteria for nutrients, so it is not a parent of this class.
    Killing may overlap predation but neither consumption, grazing nor nutritional
    benefit is required or inferred; no organismal disjointness is asserted. No exact
    synonym or phenotype xref is assigned pending authority and scope review.
  posed_by: codex
  posed_date: '2026-10-11'
- discussion_id: lethal-algicidal-strains-and-mechanisms
  prompt: Reconcile study strains and build independently supported mechanism graphs.
  kind: KNOWLEDGE_GAP
  status: OPEN
  rationale: Canonical examples await authoritative strain/taxon reconciliation, including
    HY's conflicting isolate numbers. Retain source strain names as qualified evidence
    without species-wide assignments or promotion of induced mutants. Secreted activity
    is demonstrated, not a universal restriction excluding contact-dependent routes.
    Neither a common protein mechanism, a universal lethal threshold, bloom-control
    efficacy nor environmental safety is established. Protein graphs require exact
    functional evidence and taxon-paired accessions, not a short sequence match. Mechanisms
    are deferred, not claimed absent.
  posed_by: codex
  posed_date: '2026-10-11'
curation_history:
- timestamp: '2026-10-11T08:50:39Z'
  curator: codex
  action: MINTED_TRAITMECH_ID
  changes: Added lethal algicidal activity beneath phenotype with three primary DOI
    citations and directly checked short snippets. Ignored-and-hidden main/worktree/open-PR
    checks support 000695 and v571 block 1064800-1064899. Existing records unchanged;
    mappings, canonical taxa and mechanisms remain open. Timestamp records the observed
    UTC curation decision.
  llm_assisted: true