Biofilms: The Newly Discovered LIving Structures of Bacteria!

Since the early 19th century scientist and the public alike thought that bacteria existed as single cells floating through a watery habitat. In "recent years", however, it was discovered that "common disease-causing microbes" actually live in organized, diverse communities called biofilms by adhering to moist or wetted surfaces. Some examples of these types of surfaces are used catheters, dental plaque, slippery river rocks, and most slimes. These colonies, though recently discovered, are believed to be a very well developed evolutionary strategy. The bacteria in these biofilms actually grow in "tiny enclaves which we called microcolonies", and the majority of the structure is actually composed of secretions from these bacteria labeled the "extracellular matrix" that traps water and small food particles and also provides support for this colony.

These colonies are divided by water channels that not only provide dissolved nutrients to the microbes, but they also remove waste products similar to an aqueduct built by the ancient romans. The further into the biofilm one scientist may travel, the lower the oxygen levels and thus the more dormant the cells become. Bacteria within these biofilms can also have mutually benefitting relationships by consuming the other's waste products such as the bacteria that digest cellulose in the plant matter to produce fatty acids that are consumed by Treponema, thus allowing the continuation of growth and production via a symbiotic relationship.

Along with independently existing macro-structures of bacteria, biofilms can also infect humans and be pathogenic or detrimental to the health of the host. The structure of the biofilm often prevents the colony from being penetrated by anti-bacterial agents like bleach, which encounters great difficulty breaking down the outter layers. So in order to actually combat a biofilm structure of bacteria, one must concentrate on the development and protein synthesis which occur just before a biofilm attaches itself to a surface. By manipulating certain genes, scientist can determine the specific development of a biofilm, and thusly can prevent this colony from forming an intracellular matrix which will inevitably cause its collapse. With enough of these cells assembled the concentration of the Acylated homoserine lactone compound increases, and that assembly triggers the changes in many genes, which is critical for the growth and development of these structures.

With the understanding of biofilm formation becoming more obvious, it becomes much easier for scientist and biologist to create remedies targeting these mechanism of development and interfereing with the proliferation of such biofilms. The emerging tactics being developed to attack the mechanisms of biofilm creation could eradicate the bacterial colony much more effectively than poisonous treatments of the past that could potentially harm the host. By focusing specifically on preventing development or further proliferation of such an evolutionary defensive colony, the harm to the host is completely taken out of the equation.

So, in conclusion, bacteria once believed to be a sole organism floating in a watery substance has now been replaced by the understanding and investigation of giant, complex colonies of diversified bacteria which may include its own nutrient and waste management system. Evolutionary advancements seem to permeate through all aspects of carbon based life forms. Cant wait to see what we come up with next.

Title:
Battling BIOFILMS.
Authors:
Costerton, J.W.
Stewart, Philip S.
Source:
Scientific American; Jul2001, Vol. 285 Issue 1, p74, 8p, 1 diagram, 6 color, 3 bw