[Phage associated polysaccharide depolymerases - characteristics and application].

Bacteriophages have been of interest as agents combating undesirable bacteria since their discovery nearly 100 years ago. Currently, intensive research is being conducted into two groups of phage enzymes, which cause damage to bacterial cells. The first group includes lysins responsible for breaking down the cell wall in order to release progeny phages and the second is polysaccharides depolymerases (PDs), which degrade capsular and structural polysaccharides, including exopolysaccharides (EPS) - a dominant bacterial biofilm component. PDs can be attached to a phage tail or present as a free form diffused to the medium, their production takes place constitutively or is induced by the polysaccharide presence. PDs belong to two groups of enzymes: hydrolases (glycanases) or polysaccharide lyases. These enzymes are a very heterogeneous group with regard to substrate specificity, the molecular weight or sensitivity bakteriofato physical and chemical factors. Phages producing PDs act against encapsulated infectious bacteria and have a great potential as a new class of anti-biofilm agents. Polysaccharide depolymerases depriving bacteria of the capsule, reduce their virulence and sensitize them to the immune system. The variety of biofilms forming bacteria and exopolysaccharides produced by them requires the use of specific phages producing DP. The problem of DP and phages specificity can be solved by using phage cocktails or introducing into the virus genome genes encoding enzymes degrading various bacterial exopolysaccharides important in the biofilm formation or broadening the host range. The use of DP or a DP-producing phage combined with other antibiofilm agents brings promising results. This indicates a direction for further research to develop effective methods to combat bacterial biofilms. Phage-borne PDs can be used for determination of the bacterial polysaccharides structure or efficient capsular typing.