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My fascination with biofilms continues ...
...
The cover of the November/December 2005 American Scientist features a graphic of an E. coli biofilm ...
... cool, huh?
The issue also contains a general article on biofilms ... Dr. Shimek makes comment of it in the November 2005 issue of RC's Reefkeeping.
Biofilms
A new understanding of these microbial communities is driving a revolution that may transform the science of microbiology.
Joe J. Harrison, Raymond J. Turner, Lyrium L. R. Marques, Howard Ceri
American Scientist, Vol. 93, Number 6, Page 508, 2005.
Full Text Article
From the article ...
And ...
And ...
The article also presents some graphics which may be of interest ... ignore the zeovit.com overlay. It is NOT a copyright claim ... all of these images are copyrighted to American Scientist.
Figure 2. Formation of a biofilm is analogous to the development of a multicellular organism, with intercellular signals regulating growth and differentiation. A typical biofilm forms (follow arrows from upper left) when free-swimming planktonic bacteria adsorb to a biotic or inanimate surface—an association that is initially reversible, but then irreversible. Adhesion triggers the first physiological changes on the path to a biofilm lifestyle. As the bacteria grow and divide, molecular signals passed between the cells provide information on cell density—a process called quorum sensing. In a maturing colony, the microbes produce an extracellular polymeric substance—a
matrix of polysaccharides, DNA and proteins that encases the microcolony
structure. Planktonic cells may leave the biofilm to establish new biofilm structures. Signals from the collective may also recruit new microbial species to join the consortium.
Stephanie Freese
And ...
Figure 6. Biofilms derive their extraordinary tolerance to antimicrobial compounds from several factors. Bacteria near the center of a microcolony grow very slowly because they are exposed to lower concentrations of oxygen and nutrients (1). They are thus spared the effects of antibiotic drugs, which are much more effective against fast-growing cells. Intercellular signals (2) can alter the physiology of the biofilm, causing members to produce molecular pumps that expel antibiotics from the cells and allow the community to grow even in the presence of a drug. The biofilm matrix is negatively charged (3) and so binds to positively charged antimicrobials, preventing them from reaching the cells within the colony. Specialized populations of persister cells (4) do not grow in the presence of an
antibiotic, but neither do they die. When the drug is removed, the persisters can give rise to a normal bacterial colony. This mechanism is believed to be responsible for recurrent infections in hospital settings. Finally, population diversity (5), genetic as well as physiological, acts as an "insurance policy," improving the chance that some cells will survive any challenge.
Stephanie Freese
BTW ... the American Scientist cover was done by:
edm studio
http://www.edmstudio.com/
They did a presentation on their process of generating it ...
edm studio design project:
Visualization - Biofilm
http://www.edmstudio.com/visualization/biofilm.html
JMO
My fascination with biofilms continues ...
...The cover of the November/December 2005 American Scientist features a graphic of an E. coli biofilm ...
... cool, huh?
The issue also contains a general article on biofilms ... Dr. Shimek makes comment of it in the November 2005 issue of RC's Reefkeeping.
Biofilms
A new understanding of these microbial communities is driving a revolution that may transform the science of microbiology.
Joe J. Harrison, Raymond J. Turner, Lyrium L. R. Marques, Howard Ceri
American Scientist, Vol. 93, Number 6, Page 508, 2005.
Full Text Article
From the article ...
When we think about bacteria, most of us imagine a watery milieu, with
single-celled organisms swimming about. We might envision these solitary entities getting together with some of their brethren now and then to cause some disease or spoil some food, but once the job is done they return to their isolated existence. This image of bacterial existence, it turns out, is not only oversimplified but perhaps misleading as well. In nature, the majority of microorganisms live together in large numbers, attached to a surface. Rather than living as lonely hermits in the so-called planktonic form, most bacteria spend much of their lives in the microbial equivalent of a gated community—a biofilm.
single-celled organisms swimming about. We might envision these solitary entities getting together with some of their brethren now and then to cause some disease or spoil some food, but once the job is done they return to their isolated existence. This image of bacterial existence, it turns out, is not only oversimplified but perhaps misleading as well. In nature, the majority of microorganisms live together in large numbers, attached to a surface. Rather than living as lonely hermits in the so-called planktonic form, most bacteria spend much of their lives in the microbial equivalent of a gated community—a biofilm.
A mature biofilm is a fascinating construction: It can form layers, clumps and ridges, or even more complex microcolonies that are arranged into stalks or mushroom-like formations. The residents of the biofilm may be a single species or a diverse group of microorganisms distributed in various neighborhoods. Their common bond is a matrix made of polysaccharides, DNA and proteins, which together form an extracellular polymeric substance—what many microbiologists just call slime.
It's becoming increasingly clear that the communal life offers a microorganism
considerable advantages. The physical proximity of other cells favors synergistic interactions, even between members of different species. These include the horizontal transfer of genetic material between microbes, the sharing of metabolic by-products, an increased tolerance to antimicrobials, shelter from changes in the environment and protection from the immune system of an infected host or from grazing predators. The formation of a biofilm has even been likened to the program by which cells within a multicellular organism differentiate.
considerable advantages. The physical proximity of other cells favors synergistic interactions, even between members of different species. These include the horizontal transfer of genetic material between microbes, the sharing of metabolic by-products, an increased tolerance to antimicrobials, shelter from changes in the environment and protection from the immune system of an infected host or from grazing predators. The formation of a biofilm has even been likened to the program by which cells within a multicellular organism differentiate.
The article also presents some graphics which may be of interest ... ignore the zeovit.com overlay. It is NOT a copyright claim ... all of these images are copyrighted to American Scientist.
Figure 2. Formation of a biofilm is analogous to the development of a multicellular organism, with intercellular signals regulating growth and differentiation. A typical biofilm forms (follow arrows from upper left) when free-swimming planktonic bacteria adsorb to a biotic or inanimate surface—an association that is initially reversible, but then irreversible. Adhesion triggers the first physiological changes on the path to a biofilm lifestyle. As the bacteria grow and divide, molecular signals passed between the cells provide information on cell density—a process called quorum sensing. In a maturing colony, the microbes produce an extracellular polymeric substance—a
matrix of polysaccharides, DNA and proteins that encases the microcolony
structure. Planktonic cells may leave the biofilm to establish new biofilm structures. Signals from the collective may also recruit new microbial species to join the consortium.
Stephanie Freese
Figure 6. Biofilms derive their extraordinary tolerance to antimicrobial compounds from several factors. Bacteria near the center of a microcolony grow very slowly because they are exposed to lower concentrations of oxygen and nutrients (1). They are thus spared the effects of antibiotic drugs, which are much more effective against fast-growing cells. Intercellular signals (2) can alter the physiology of the biofilm, causing members to produce molecular pumps that expel antibiotics from the cells and allow the community to grow even in the presence of a drug. The biofilm matrix is negatively charged (3) and so binds to positively charged antimicrobials, preventing them from reaching the cells within the colony. Specialized populations of persister cells (4) do not grow in the presence of an
antibiotic, but neither do they die. When the drug is removed, the persisters can give rise to a normal bacterial colony. This mechanism is believed to be responsible for recurrent infections in hospital settings. Finally, population diversity (5), genetic as well as physiological, acts as an "insurance policy," improving the chance that some cells will survive any challenge.
Stephanie Freese
BTW ... the American Scientist cover was done by:
edm studio
http://www.edmstudio.com/
They did a presentation on their process of generating it ...
edm studio design project:
Visualization - Biofilm
http://www.edmstudio.com/visualization/biofilm.html
JMO
BTW, I lov the GFP biofilm cover pix
Bob
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