Harnessing Potential of Phage Cocktail for Bacterial Reduction in Wastewater Treatment: A Pilot-Scale Demonstration of a Sustainable Approach
摘要
Water security is a critical global challenge, with water-borne bacterial pathogens in wastewater posing significant public and environmental health risks. Traditional disinfection methods are costly and regulated due to residual harmful by-products, making bacteriophages a promising biological alternative for sustainable wastewater treatment. The current work explored the potential of bacteriophages as an alternative biological method for ameliorating wastewater quality. The objective of the study was to isolate phages from wastewater, test its host range, characterize it and formulate a cocktail to demonstrate its reduction potential in actual wastewater system. A total of 39 bacteriophages were isolated from seven wastewater samples collected from four wastewater treatment plants (WWTPs) in Mumbai. Host range analysis showed that, of the 248 enteric bacterial isolates tested, only 22 isolates were susceptible to phage lysis. These isolates were identified by MALDI-TOF and were found to be E. coli (18), Citrobacter freundii (3) and S.typhimurium (1). Three phages, vB_EcoM-RP5 & vB_EcoM-R2 (against E. coli) and vB_CfrM-Q15 (against Citrobacter freundii), were used as cocktail for bacterial reduction study. TEM analysis revealed that all three phages belonged to the family Myoviridae and order Caudovirales. The phages exhibited temperature and pH stability in the range of 20–50 °C and pH 5–8. Pilot-scale bacterial reduction experiment carried out in secondary treated wastewater at MOI 10 resulted in log reduction of 0.97 ± 0.03 (Mean ± S.D) for total heterotrophic count, (p < 0.05), 1.01 ± 0.10 (Mean ± S.D) for coliforms (p < 0.05), and 1.00 ± 0.05 (Mean ± S.D) for E. coli (p < 0.05) at 6 h time interval. The work thus highlights the possibility of using bacteriophages as a sustainable and eco-friendly alternative for wastewater treatment.
Graphical Abstract