In situ evidence for metabolic and chemical microdomains in the structured polymer matrix of bacterial microcolonies

• Published in: FEMS microbiology ecology 2016-11, Vol.92 (11), p.1
• Main Authors: Lawrence, J. R., Swerhone, G. D. W., Kuhlicke, U., Neu, T. R.
• Format: Article
• Language: English
• Subjects: Bacteria; Beads; Betaproteobacteria - enzymology; Betaproteobacteria - metabolism; Betaproteobacteria - physiology; Biofilms - growth & development; Cell Membrane - chemistry; Cell surface; Cellular Microenvironment - physiology; Chemical properties; Chlorides; Colonies; Concentration gradient; Ecology; Fluorescence; Fluorescent Dyes; Fluorescent indicators; Glucose oxidase; Membrane Microdomains - chemistry; Metabolism; Microbial colonies; Microbial metabolism; Microbiological research; Microbiology; Microscopy, Confocal; Nutrients; Permeability; pH effects; Phosphoric Monoester Hydrolases - metabolism; Physiological aspects; Polymeric composites; Polymers; Polymers - chemistry; Potassium chloride; Potassium Cyanide - chemistry; Rhodamine; Structure-function relationships
• ISSN: 1574-6941; 0168-6496; 1574-6941
• DOI: 10.1093/femsec/fiw183

CLSM and fluorescent probes were applied to assess the structure, composition, metabolic activity and gradients within naturally occurring β-proteobacteria microcolonies. Extracellular polymeric substances (EPS) as defined by lectin-binding analyses had three regions: (i) cell associated, (ii) intercellular and (iii) an outer layer covering the entire colony. We assessed structural, microenvironmental and metabolic implications of this complex EPS structure. Permeability studies indicated that the outer two layers were permeable to 20 nm beads, intercellular EPS to