Induction of viable but non culturable states (VBNC) in two bacteria strains by addition of H2O2 to natural groundwater upon simulated sunlight

JOH JAIRON ALVEAR DAZA; HECTOR MARIO GUTIERREZ ZAPATA; JULIAN RENGIFO; PAULA OSORIO-VARGAS; ALEJANDRA GARCIA BARCO; JANETH SANABRIA

Natal

Congreso; IV Iberoamerican conference on advanced oxidation technologies; 2019

Addition of 10 mg L-1 of H2O2 into natural groundwater containing natural amounts of total iron (0.30-0.39 mg L-1) and irradiated by simulated sunlight irradiation exhibited a dropping of E. coli and K. pneumoniae culturability after 70 and 120 min respectively. However, viability measurements revealed that only E. coli cells underwent a total inactivation after 360 min of irradiation while K. pneumoniae remains in xlog, demonstrating that this oxidation process could induce viable but non-culturable states (VBNC). SEM micrographs showed morphological changes in the bacteriashape according to VBNC states. Post-irradiation effects were also observed. Chemical features of groundwater (presence of ferrous iron, iron oxyhydroxides, ferric-low molecular dissolved organic matter complexes, fluoride and bicarbonates) make that specifically these water samples seem to be promising to remove microbiological pollution by H2O2/sunlight treatments