Inhibition of biofilm formation on UF membrane by use of specific bacteriophages

A model ultrafiltration (UF) continuous recycled system fed with previously sterilized effluents (two sources) was experimentally inoculated with three bacterial species: Pseudomonas aeruginosa, Acinetobacter johnsonii and Bacillus subtilis (separately and combined). Subsequently, the corresponding specific lytic bacteriophages were supplemented versus control (bacteria without phages) and the experimental set-up was operated for >80 h. The seeded phages lytic activity reduced membrane biofouling by an average of 40% to >60% compared to control. Concentrate phage numbers increased accordingly and some were found in the permeate, however inoculated bacteria were not found in the permeate. Combinations of one, two and three bacterial species in parallel with their specific phages, revealed significant and efficient inactivation rates as well reduced biofouling as detected with high resolution electron scaning microscope (HSEM) and permeability test. The results suggest on potential use of specific lytic phages to prevent UF membrane biofouling. Additionally, future application of specific bacteriophages concept in other membrane processes such as: nanofiltration and reverse osmosis, that encounter less bacterial species diversity, can be successful.