Evaluation of the photocatalytic inactivation efficiency of dairy bacteriophages

In this paper, the photocatalytic inactivation efficiency of phages infecting lactic acid bacteria (LAB) was evaluated. Ten bacteriophages (ATCC 15807-B1, 832-B1, 0241, 204, 342, MLC-A, J-1, OBJ, CHD and QF9) dispersed on TiO2-coated plates were exposed to UV-A radiation during different periods of time. Two kinds of efficiencies were defined and assessed: (i) the apparent photonic yield and (ii) the quantum yield of inactivation. Considering all phages studied in this work, dissimilar values of inactivation efficiencies were found; the results differ in more than one order of magnitude. The highest inactivation efficiency was found for the bacteriophage J-1, whereas the lowest one was obtained for the phage 342. The data presented in this work can provide useful information to design innovative and effective treatments to be applied in laboratories and industrial plants which handle LAB strains.

► The photocatalytic inactivation efficiency is evaluated for ten phages infecting lactic acid bacteria (LAB).
► The apparent photonic yield and the quantum yield of inactivation are assessed.
► The highest inactivation efficiency is found for the bacteriophage J-1, whereas the lowest one is obtained for the phage 342.
► Results show that photocatalysis can be applied in laboratories and industrial plants handling LAB strains which represent target of bacteriophage attacks.