slime layer

GO:0030114 · Envelope · Envelope layer · Proposed

A slime layer is an easily removed, diffuse, unorganized layer of extracellular material that surrounds a cell. Specifically this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. [GO:0030114]

Xrefs: uniprot.location:SL-0247 — Slime layer

UniProt location names: UniProt Consortium, CC BY 4.0. Reference label and route sources.

Components

Component	Type	Part of / acts on	Grounding	Genes	Stoichiometry	Essential	Role
slime-layer extracellular material	Other	part of	Reviewed label only (reviewed name; no accession asserted)			ESSENTIAL	Forms the loose, diffuse extracellular glycocalyx matrix that surrounds the cell surface. `GO:0030114` GO:0030114 defines a slime layer as diffuse extracellular material that surrounds a cell and consists mostly of exopolysaccharides, glycoproteins and glycolipids. `DOI:10.1042/bj1120521` Brown, Foster and Clamp 1969 chemically characterized Pseudomonas aeruginosa slime as predominantly polysaccharide with additional nucleic acid material and minor protein.

Canonical examples

NCBITaxon:287 Pseudomonas aeruginosa — Classic biochemical example in which extracellular slime from multiple Pseudomonas aeruginosa strains was chemically analyzed. [DOI:10.1042/bj1120521]

Mechanism graphs

Extracellular material forms a loose glycocalyx (ASSEMBLY)

Mixed extracellular material accumulates as a diffuse, easily removed slime layer rather than as a highly organized capsule.

Subject	Predicate	Object	Evidence
slime-layer extracellular material	forms	slime layer	`GO:0030114` GO:0030114 defines the slime layer by diffuse extracellular material. `DOI:10.1042/bj1120521` Brown, Foster and Clamp 1969 found Pseudomonas aeruginosa slime to be predominantly polysaccharide with nucleic acid material and minor protein.
slime layer	surrounds	cell surface	`GO:0030114` GO:0030114 defines the slime layer as surrounding a cell. `uniprot.location:SL-0247` — Slime layer UniProt Subcellular Location entry SL-0247 describes the slime layer as extracellular material that surrounds the bacterial cell.

Discussions

CURATION_TODO (RESOLVED): Keep diffuse slime layers separate from the organized capsule record. GO:0030114 and UniProt SL-0247 denote a loose, diffuse glycocalyx that is easily removed, whereas GO:0042603 denotes the organized capsule subclass of glycocalyx; slime layer therefore belongs in a separate sibling record.
CURATION_TODO (OPEN): Resolve exact source-neutral groundings for slime-layer matrix material. This first slime-layer record curates a broad extracellular matrix component while leaving exact glycan, glycoprotein and glycolipid identifiers open for species-specific follow-up.

Evidence

GO:0030114 Gene Ontology cellular-component term for slime layer.
GO:0030112 Gene Ontology cellular-component parent term for the carbohydrate-rich glycocalyx.
uniprot.location:SL-0247 — Slime layer UniProt Subcellular Location entry SL-0247 maps Slime layer to GO:0030114 and describes it as a more-diffuse glycocalyx than a capsule.
DOI:10.1042/bj1120521 Brown MRW, Foster JHS and Clamp JR 1969, 'Composition of Pseudomonas aeruginosa slime', Biochemical Journal.

Curation history

2026-09-12T16:38:17Z codex · CREATED_RECORD — Scaffolded by scripts/new_record.py
2026-09-12T16:38:46Z codex · EXPANDED_RECORD — Added glycocalyx parentage, the UniProt Subcellular Location xref, a reviewed-label-only slime-layer extracellular-material component, a Pseudomonas aeruginosa canonical example, record-level GO/UniProt/DOI evidence, a nonmechanistic diffuse-matrix graph, and capsule-boundary plus matrix-grounding discussions.
2026-09-12T16:44:02Z codex · ADDRESS_REVIEW — Resolved #677 by adding GO:0042603 evidence to the capsule-boundary discussion; resolved #678 by narrowing the matrix grounding note so GO- and UniProt-specific composition claims are attributed separately.

Source: data/structures/envelope/slime_layer.yaml