3. INTRODUCTION
• A biofilm is any group of microorganisms in
which cells stick to each other and often also to a
surface.
• Biofilms may form on living or non-living surfaces
and can be prevalent in natural, industrial and
hospital settings. The microbial cells growing in a
biofilm are physiologically distinct
from planktonic cells of the same organism, which,
by contrast, are single-cells that may float or swim
in a liquid medium
4.
5. FORMATION
• The formation of a biofilm begins with the
attachment of free-floating microorganisms
to a surface.
• It is thought that the first colonist bacteria of
a biofilm adhere to the surface initially
through weak, reversible adhesion via van
der Waals forces and hydrophobic effects.
7. DISPERSAL
• Dispersal of cells(bacteria) from the biofilm
colony is an essential stage of the biofilm life
cycle.
• Dispersal enables biofilms to spread and
colonize new surfaces.
• Enzymes that degrade the biofilm extracellular
matrix, such as dispersin B and
deoxyrobonuclease, may play a role in biofilm
dispersal
8.
9. PROPERTIES
The EPS matrix consists of exopolysaccharides,
proteins and nucleic acids. A large proportion
of the EPS is more or less strongly hydrated,
however, hydrophobic EPS also occur; one
example is cellulose which is produced by a
range of microorganisms.
This matrix encases the cells within it and
facilitates communication among them
through biochemical signals as well as gene
exchange.
10. HABITAT
Biofilms are ubiquitous in organic life.
Non-shedding surface in non-sterile aqueous
or humid environment.
Hot springs
Glaciers
On rocks pebbles.
Bottom of most streams or rivers and on the
surface of stagnant pools.
Part of food chain in rivers.
On the surface of and inside the plant.
In showers, sewage pipes.
11. Thermophilic bacteria in the outflow
of Mickey Hot Springs, Oregon,
approximately 20 mm thick.
Mats of bacterial biofilm colour the hot
springs in Yellowstone National Park. The
longest raised mat area is about half a meter
long.
Biofilms grown in showers
13. The food and beverage industry is confronted daily with a
recurring threat of production sites: the prevention and
eradication of biofilms (nests of bacteria protected by an
organic matrix). Biofilms are 1,000 times more resistant to
biocides than planktonic (free) cells and there are 1,000 to
10,000 times more bacteria growing in a biofilm rather than
as planktonic cells. Biofilms therefore represent a major risk
for the quality of the final products, as well as for the public
health and economy.
14. The bulk of the microorganisms that form the
biofilm on teeth are Streptococcus mutans and
other anaerobes, though the precise composition
varies by location in the mouth. Examples of such
anaerobes
include fusobacterium and actinobacteria.
15. Pseudomonas aeruginosa
represents a commonly used biofilm model organism since it is
involved in different types of biofilm-associated
infections. Examples of such infections include chronic wounds,
chronic otitis media, chronic prostatitis and chronic lung
infections in cystic fibrosis (CF)
16.
17.
18. USES
Used as a bioreactor.
They're also a major food source
for invertebrates, which feed larger
animals like fish.
In streams, biofilms contribute to
water quality by recycling nutrients
and organic matter.
19. EUKARYOTIC BIOFILM
In the environment, fungal biofilms are
an area of ongoing research. One key area
of research are fungal biofilms on plants.
For example, in the soil, plant associated
fungi including mycorrhiza have been
shown to decompose organic matter,
protect plants from bacterial pathogens
Biofilms in aquatic environments are
often founded by diatoms.
