Please enable JavaScript.

Coggle requires JavaScript to display documents.

Microbiology (Biofilms ('a structured community of microorganisms…

- - - - why do biofilms form ?
        
        Protection/self defence- antibiotics/toxins resist physical forces like toxins or phagocytosis
        
        Nutrient consumption from surface
        
        Intracellular communication- allows bacterial cells to live in close association with each other
      - cells in a biofilm can come 10-1000 times more resistant to effect of antimicrobial agents
        
        Key concepts
        
        Colonisation - intercellular communication, growth and polysaccharide formation
        
        Development - further growth and polysaccharide)
        
        Attachment - adhesion of cells to suitable surface
        
        Active dispersal - triggered by environmental factors such as nutrient availability cells signal for dispersal.
      - Composition of Biofilms
        
        live cells
        
        dead cells
        
        extracellular polymeric substances (EPS)
        
        carbohydrate DNA
        
        Water
        
        Polysaccharides proteins DNA (eDNA) key support of biofilm showing up recurrent in biofilms but not much information on it!!
        distributed between cells in a non-homogeneous pattern setting up differences in region of the matrix
        
        Weak physiochemical interactions and entanglement of biopolymers facilitate the stability of the EPS
        look at functions of EPS powerpoint
      - 97% of biofilm is made up of water
        
        bacterial adhesion to a hard substratum described as a multi level process
        
        adsorption of chemical species for conditioning film before anything
        (more next year)
        
        cell transport
        
        Convective motion (liquid flow)
        
        Active motion (flagella)
        
        Brownian motion (diffusion)
        
        Attachment
        
        reversible
        
        secondary minimum
        
        irreversible
        
        primary minimum (EPS)
        
        fimbriae/ pills pay a role in attachment flagella role to overcome repulsive forces rather than direct attachment
        
        Heterogeneity in Biofilms
      - Where and Why: industrial and medical implications
        
        Teeth, oil recovery,medical implants, cooling water, food processing, drinking water, paper manufacturing, ship hulls
        
        Biofilms can act as a food source for larger organisms which can lead to corrosion NIH; estimate that 80% of chronic infection is biofilm related
        
        Teeth: bad breath, caries, inflammation
        
        Micro fouling: Biofilms (slime)