Adhesion of bacteria on pectin casted films.

Pectin and non-pectin degrading bacteria were tested for their ability to adhere to a film casted of low methoxylated pectin (polygalacturonic acid). Klebsiella oxytoca and a newly isolated strain of Escherichia coli adhered to the film, whereas only K. oxytoca was able to utilize pectin as a sole carbon source. Other E. coli strains, containing plasmids with pectinolytic enzymes, did not adhere to the solid pectin film. Therefore, the ability of the bacteria to adhere to the films was not correlated with their ability to degrade pectin. When the solubilization (dissolution) of pectin matrices (tablets) was analysed with and without K. oxytoca, a significant retardation in the dissolution rate was observed in the presence of K. oxytoca, suggesting the formation of a biofilm on the matrix or sedimentation of insoluble pectin salts.