Discuss biofilms with regard to their formation, unique properties, and signific
ID: 274022 • Letter: D
Question
Discuss biofilms with regard to their formation, unique properties, and significance to the environment and the human body. Explain how a biofilm differs from a typical bacterial colony growing on a nutrient agar medium. Discuss biofilms with regard to their formation, unique properties, and significance to the environment and the human body. Explain how a biofilm differs from a typical bacterial colony growing on a nutrient agar medium. Discuss biofilms with regard to their formation, unique properties, and significance to the environment and the human body. Explain how a biofilm differs from a typical bacterial colony growing on a nutrient agar medium.Explanation / Answer
Q) A Biofilm is a thick layer of prokaryotic organisms which are aggregated to form a colony. The colony attaches to a surface with a slime layer, which helps in protecting the microorganisms. Biofilms are found in all environments, a biofilm usually begins to form when a free-swimming bacteria, attaches to a surface.
Biofilm is formed by cell-to-cell communication. It is first formed when one or a few cells attach to a surface. These cells produce proteins which, act as signals for the nearby cells. These signals are detected by the neighbouring cells and as a result they add new cells into the colony. When the nearby cells detect the chemical, they aggregate and starts forming the biofilm. These cells then send additional signals, and add more cells to the colony the biofilm grows. The proteins also signal the development of polysaccharides which forms the slime layer. This slime layer surrounds the growing colony. The slimy layer is made up of many porous layers with channels, which helps the cells in the center of the colony to receive nutrients and remove the waste products.
Hydrophobicity is the repelling nature of a molecule from water, it helps the bacteria to form biofilms. Bacteria with more hydrophobicity has less repulsion between the extracellular matrix and the bacterium. Some bacteria are not able to attach to a surface on their own properly, due to their less motility, rather they are able to anchor themselves to the matrix or directly to other earlier bacterial colonies. Non-motile bacteria are not able to recognize surfaces and are not able to aggregate together easily, when compared to the motile bacterias.
Unique properties of biofilms:-
The same bacteria shows different property when found in a biofilms as compared to when it is found in a single cell stage or in planktonic form. The bacteria found in a biofilm are more resistant to antibiotics. Biofilm cells can communicate with each other by biochemical signalling molecules. Quorom sensing is seen in biofilms.
Biofilms are dynamic and respond to their environment, they can get adapted to the changes in their environment.
The property of detachment is common in all biofilms. Bacterial cells can detach from their biofilm colony either personally or in a group. When a single microorganisms detaches from a biofilm, these detached microorganisms are easy to kill by the chemicals designed to kill them. When microorganisms detach from their biofilm colony in clumps or groups, the clumps are pieces of the biofilm which are not attached to a surface, maintain the protective properties of the original biofilm and are thus more difficult to kill. In the right conditions, biofilms can migrate across the surfaces over a period of time in a variety of ways.
The microorganisms in a biofilm aggregate to form a colony for metabolic cooperation. This cooperative method of growth increases the cells’ survival by increased defence system, also by more availability of nutrients, and cellular communication and by the transfer of genetic material.
Cellular defence is important to protect themselves from physical threats like displacement by a flowing fluid or removal by the immune system. The polysaccharide coating on the biofilm acts as an adhesive to attach the colony to a surface. This prevents the removal of the cells by a physical force. It also prevents the penetration of the biofilm by the immune system or antibiotics. Biofilms are difficult to remove and can put adverse effect on human health. For example, in cystic fibrosis a biofilm is formed in the lungs leading to adverse symptoms. Dental plaque is also another example of a bacterial biofilm, this leads to cavities and gum diseases. Some other bacterial conditions also occur by biofilms like cholera, tuberculosis, and Legionnaire’s disease.
The biofilm gives a favourable environment to the microorganisms. The cells adhere to a surface due to more nutrient resources. The cells are close to each other, which makes the cellular communication easy by signal molecules. This closeness also helps in increasing the opportunity for horizontal gene transfer, or exchange of genetic material in between the cells.
How a biofilm differs from a typical bacterial colony growing on a nutrient agar medium-
Nutrient agar gives a suitable medium for the growth of bacterial colony by the cell division of a single bacterium.
But a biofilm is more complex in it's development and structure. It is a complex aggregation of microorganisms growing on a solid substrate, It's characteristic features are it's structural heterogeneity and genetic diversity. Also a biofilm shows complex community interaction, that is in cell-cell interactions or communication, and it also shows an extracellular matrix of polymeric substances. Biofilm have the EPS matrix and are usually made up of many species of microbes, usually working together to promote growth. The EPS matrix (which makes up the majority of the biofilm) helps them grow in whatever surface they want it colonizes and protects the cells. But in case of bacterial colony growing on agar the bacteria is specific to the growing medium.
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.