Bacteriophage-based biocontrol of biological sludge bulking in wastewater

Abstract

Previously we reported, the first ever application of lytic bacteriophage (virus)-mediated biocontrol of biomass bulking in the activated sludge process using Haliscomenobacter hydrossis as a model filamentous bacterium. In the current study we extended the biocontrol application to another predominant filamentous bacterium, Sphaerotilus natans, known to be a notorious cause of filamentous bulking in wastewater treatment systems. Similar to the previous study,1 one lytic bacteriophage was isolated from wastewater that could infect S. natans and cause lysis. Significant reduction in sludge volume index and turbidity of the supernatant was observed in batches containing S. natans biomass following addition of lytic phages. Microscopic examination confirmed that the isolated lytic phage can trigger the bacteriolysis of S. natans. This extended finding further strengthens our hypothesis of bacteriophage-based biocontrol of overgrowth of filamentous bacteria and the possibility of phage application in activated sludge processes, the world's most widely used wastewater treatment processes. © 2011 Landes Bioscience.