MICR 2420 Chapter Notes - Chapter 4.6: Biofilm, Lipopolysaccharide, Polysaccharide
23 Oct 2014
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Single or multiple species, on organic and inorganic surfaces. Pseudomonas aeruginosa form single species biofilm on lungs of patiens with cystic fibrosis or on medical implants. Stages of biofilm development initiation, maturation, maintenance and dissolution. Biofilms form when nutrients are plentiful, goal to stay where this is. When scarce individuals detach from community to forage for new sources of nutrient. Biofilms many different forms and different functions for species. Can be cued by different signals ph, iron concentration, temperature, oxygen availability and the presence of certain amino acids. Cells move along surface by twitching motility (extension and retraction of certain pilus) they then stop moving and attach to surface. More cells bind they communicate with each other by sending and receiving chemical signal molecules process called quorum sensing. When reaches a certain number the signal reaches a specific concentration that cells can sense, triggers genetically regulated changes that cause cells to bind tenaciously to substrate and to each other.
