Magnetized viruses attack challenging bacteria in water-treatment systems
By Mary Page Bailey |
Biofilms in water-treatment systems may harbor problematic bacteria and pathogens since chemical disinfectants typically do not penetrate the biofilm. Now, a new treatment approach developed in the laboratory of Pedro Alvarez at Rice University (Houston; www.rice.edu) could enable the controlled penetration of biofilms to attack harmful, difficult-to-treat bacteria. The Rice team is using bacteriophages (viruses that kill bacteria) that have been attached to specially designed magnetized nanoclusters. In the presence of a weak magnetic field, the nanoclusters can be guided through a biofilm, where the attached phages can infect the targeted bacteria. Variations in strength and duration of the magnetic field can control penetration depth, and horizontal migration is driven by moving the magnet in a particular direction.
The configuration of the phage-nanocluster complex is paramount to ensure its effectiveness in attacking bacteria. First, the orientation of the phage is crucial — the phage must attach to the nanocluster at its head so that the tail fibers that initiate infection are exposed, explains Alvarez. The surface chemistry of the nanoclusters is also quite important. Consisting of iron oxide, sulfur and carbon, the nanoclusters…