A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells. Specifically, this consists mostly of exopolysaccharides, glycoproteins, and glycolipids. Therefore, the slime layer is considered as a subset of glycocalyx. While slime layers and capsules are found most commonly in bacteria, while rare, these structures do exist in archaea as well. This information about structure and function is also transferable to these microorganisms too. Structure Slime layers are amorphous and inconsistent in thickness, being produced in various quantities depending upon the cell type and environment. These layers present themselves as strands hanging extracellularly and forming net-like structures between cells that were 1-4μm apart. Researchers suggested that a cell will slow formation of the slime layer after around 9 days of growth, perhaps due to slower metabolic activity. A bacterial capsule is similar, but is more rigid than the slime layer. Capsules are more organized and difficult to remove compared to their slime layer counterparts. Another highly organized, but separate structure is an S-layer. S-layers are structures that integrate themselves into the cell wall and are composed of glycoproteins, these layers can offer the cell rigidity and protection. Because a slime layer is loose and flowing, it does not aide the cell in its rigidity. While biofilms can be composed of slime layer producing bacteria, it is typically not their main composition. Rather, a biofilm is made up of an array of microorganisms that come together to form a cohesive biofilm. Although, there are homogeneous biofilms that can form. For example, the plaque that forms on the surfaces of teeth is caused by a biofilm formation of primarily Streptococcus mutans and the slow breakdown of tooth enamel. Cellular function The function of the slime layer is to protect the bacteria cells from environmental dangers such as antibiotics and desiccation. The slime layer allows bacteria to adhere to smooth surfaces such as prosthetic implants and catheters, as well as other smooth surfaces like petri-dishes. Researchers found that the cells adhered themselves to the culture vessel without additional appendages, relying on the extracellular material alone. While consisting mostly of polysaccharides, a slime layer may be over produced such that in a time of famine the cell can rely on the slime layer as extra food storage to survive. In addition, a slime layer may be produced in ground dwelling prokaryotes to prevent