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Biofilm Prevention and Control

Bacterial colonisation of surfaces in an aqueous environment is a basic strategy for survival in nature, as nutrients are more available at the solid-liquid interface. Unfortunately these colonies or 'biofilms' as they are commonly known costs the economy millions of pounds every year, and it is highly likely biofilm affects your household or business. All industries are affected by biofilm, especially those which rely on a water supply of some description. 80% of all infections come through a water source. Biofilm will block filters and pipes and rapidly lead to corrosion of equipment.

Illustration of the five stages of biofilm growth

1. Transport of bacterial cells from the bulk liquid to the surface

2. Irreversible adsorption of bacterial cells at a surface

3. Production of cell–cell signalling molecules and EPS

4. Transport of substrates to and within the biofilm; accompanied by cell growth and replication

5. Partial or total biofilm removal by detachment/dispersion

 

Biofilms do not form by accident. The earliest evidence of organisms in the fossil record comes in the form of stromatolites, thought to be the 3.4 billion year old fossilized remnants of cyanobacterial biofilms. It is no surprise therefore that these biofilm structures involve staggering complexity.

 

The complex world of biofilms

EPS is responsible for binding cells and other particulate materials together (cohesion), to the surface (adhesion), and acts as a shield, protecting the internal cells environmental pressures. EPS comprises polysaccharides, proteins, nucleic acids, lipids, phospholipids, and humic substances.

The successful adaptation of bacteria to changing conditions is dependent on their ability to sense and respond to the external environment. The process of quorum sensing provides a mechanism for self-organisation and regulation of microbial cells. It involves an environmental sensing system that allows bacteria to monitor and respond to their own population densities. The bacteria produce a diffusible organic signal, originally called an auto-inducer (AI) molecule, which accumulates in the surrounding environment during growth. High cell densities result in high concentrations of signal, and induce expression of certain genes and/or physiological changes in neighbouring cells.

Extracellular polymeric substances (EPS)

Cell to cell communication

Conventional treatments that involve large doses of biocide or antibiotics, detrimental to the environment and above the toxic threshold need replaced. At Bridge Biotechnology we have a track record in treating biofilm extremely effectively.

D. Davis - From: Looking for Chinks in the Armor of Bacterial Biofilms Monroe D PLoS Biology Vol. 5, No. 11, e307