Methods, compositions and systems for controlling fouling of a membrane

A method of improving the permeability of a membrane used in a waste water treatment process, the method comprising subjecting the membrane to an effective amount of one or more bacterial strains capable of reducing or preventing undesirable biofilm formation on the membrane, wherein the one or more bacterial strains is selected from the Bacillus subtilis strain having the deposit accession number NRRL B-50136, the Bacillus amyloliquefaciens strain having the deposit accession number NRRL B-50141 and the Paenibacillus azotofixans strain having the deposit accession number ATCC 35681.