The application of phage reactivation capacity to sens bacterial viability and activity after photocatalytic treatment.

We purpose in this study to develop a reliable and low-cost method for the detection of Viable but nonculturable (VBNC) bacteria. Indeed, after water disinfection, injured-VBNC bacteria can be underestimated using conventional assessment methods, causing false-negative results and, posing a significant and potential health risk. The VBNC bacterial survival strategy can hide the real microbial quality of treated water. To overcome this bacterial assessment limitation, we were used a specific and lytic phage to monitor the presence of active bacteria; Pseudomonas aeruginosa after photocatalytic treatment. Within 2 h of phage-target bacteria contact, the reduction of phage amplification rate (A_t) can reveal the ability of specific-lytic phage to recognize and to attach to their host cells with a probability of new infectious phages release despite their lose of cultivability in the usual media. The determination of phage reactivation coefficient (R_t) after 2 and 8 h of phage-target cell contact time reveals the ability of phages to reactive their infectivity and their amplification in positive correlation with their host cells viability and activity. The increase in phage reactivation coefficient (R_t) after an extension of the latent period was directly related to the positive interaction between infectious phages and potential active bacteria. The use of this method can improve the water disinfection process and avoid public health-hazardous especially related to the resuscitation of active-nonculturable bacteria mainly for pathogenic bacteria. [ABSTRACT FROM AUTHOR]