MICR 2420 Lecture Notes - Lecture 16: Lichen, Exosphere, Algae

• School: University of Guelph
• Department: Microbiology
• Course: MICR 2420
• Professor: Ajila Chandran Matheyambath

Document Summary

Biofilm eps/matrix: extracellular polymeric substances, polysaccharides, nucleic acids, proteins, lipids, outer membrane vesicles, functions of the matrix, adhesion, aggregation of cells, nutrients, energy, protection host immune response and antibiotic resistance. Biofilms at an air-liquid interface: for many bacteria, sessile cells in a biofilm chemically talk to each other in order to build microcolonies and keep water channels open. Quorum sensing: the phenomenon was originally dubbed quorum sensing because it seemed akin to parliamentary rules of order that require a minimum number of members to be present at a meeting in order to conduct business. In the microbial world, however, gene regulation is only loosely associated with actual cell numbers. Quorum sensing and pathogenesis: many pathogens use quorum sensing to control virulence genes, pseudomonas aeruginosa. Its virulence proteins include proteases and other degradative enzymes: these are not produced until cell density is fairly high, and can overwhelm its host.