Legionella jordanis inactivation in water by solar driven processes: EMA-qPCR versus culture-based analyses for new mechanistic insights

María Inmaculada Polo-López, María Castro-Alférez, Samira Nahim-Granados, Sixto Malato, Pilar Fernandez-Ibanez

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

In this contribution, the validation of EMA-qPCR method for the quantification of viable Legionella spp. in water after solar treatments was carried out. EMA-qPCR was used to evaluate the different effects of several solar water disinfection processes over this bacterium, and furthermore their mode of action. Inactivation of Legionella jordanis in water by solar photocatalytic (TiO2 and TiO2/H2O2) and solar photochemical (solar/H2O2 and solar disinfection) processes have been investigated under natural sunlight. Culture-based and molecular (EMA-qPCR) techniques were systematically compared for the analysis of treated water samples. Solar tests were done under natural solar radiation (clear sky) and ambient temperature (20–35 °C) for 2 h, using H2O2/Solar (10, 20 and 50 mg/L), TiO2/Solar (100, 200, 300, 400, and 500 mg/L) and TiO2/H2O2/Solar (100/10, 200/10, 500/10 mg/L). According to culture-based method, the best results of bacterial inactivation were obtained for 500/10 mg/L of TiO2/H2O2. The order of efficiency to reach complete inactivation was: TiO2/H2O2/solar (5 min) > TiO2/solar (15 min) ≈ H2O2/solar (15 min) > Solar only disinfection (90 min). Moreover, EMA-qPCR and culturable counting results showed a direct correlation for samples treated with TiO2/solar for those catalyst concentrations that generate a strong oxidative attack over the cell wall. EMA-qPCR results demonstrated to be a good method to detect damaged and dead cells when the treatment affects the integrity of the cell’s membrane, as occurs under photocatalysis. Meanwhile for solar disinfection and solar/H2O2 (at non-toxic concentrations,
LanguageEnglish
JournalCatalysis Today
VolumeN/A
DOIs
Publication statusAccepted/In press - 23 Oct 2016

Fingerprint

Disinfection
Water
Photocatalysis
Cell membranes
Solar radiation
Bacteria
Cells
Catalysts
Temperature

Keywords

  • EMA
  • Legionella jordanis
  • Real time qPCR
  • TiO2
  • Hydrogen peroxide

Cite this

Polo-López, María Inmaculada ; Castro-Alférez, María ; Nahim-Granados, Samira ; Malato, Sixto ; Fernandez-Ibanez, Pilar. / Legionella jordanis inactivation in water by solar driven processes: EMA-qPCR versus culture-based analyses for new mechanistic insights. In: Catalysis Today. 2016 ; Vol. N/A.
@article{93c39bbc53c34914bd57b788724a479a,
title = "Legionella jordanis inactivation in water by solar driven processes: EMA-qPCR versus culture-based analyses for new mechanistic insights",
abstract = "In this contribution, the validation of EMA-qPCR method for the quantification of viable Legionella spp. in water after solar treatments was carried out. EMA-qPCR was used to evaluate the different effects of several solar water disinfection processes over this bacterium, and furthermore their mode of action. Inactivation of Legionella jordanis in water by solar photocatalytic (TiO2 and TiO2/H2O2) and solar photochemical (solar/H2O2 and solar disinfection) processes have been investigated under natural sunlight. Culture-based and molecular (EMA-qPCR) techniques were systematically compared for the analysis of treated water samples. Solar tests were done under natural solar radiation (clear sky) and ambient temperature (20–35 °C) for 2 h, using H2O2/Solar (10, 20 and 50 mg/L), TiO2/Solar (100, 200, 300, 400, and 500 mg/L) and TiO2/H2O2/Solar (100/10, 200/10, 500/10 mg/L). According to culture-based method, the best results of bacterial inactivation were obtained for 500/10 mg/L of TiO2/H2O2. The order of efficiency to reach complete inactivation was: TiO2/H2O2/solar (5 min) > TiO2/solar (15 min) ≈ H2O2/solar (15 min) > Solar only disinfection (90 min). Moreover, EMA-qPCR and culturable counting results showed a direct correlation for samples treated with TiO2/solar for those catalyst concentrations that generate a strong oxidative attack over the cell wall. EMA-qPCR results demonstrated to be a good method to detect damaged and dead cells when the treatment affects the integrity of the cell’s membrane, as occurs under photocatalysis. Meanwhile for solar disinfection and solar/H2O2 (at non-toxic concentrations,",
keywords = "EMA, Legionella jordanis, Real time qPCR, TiO2, Hydrogen peroxide",
author = "Polo-L{\'o}pez, {Mar{\'i}a Inmaculada} and Mar{\'i}a Castro-Alf{\'e}rez and Samira Nahim-Granados and Sixto Malato and Pilar Fernandez-Ibanez",
year = "2016",
month = "10",
day = "23",
doi = "10.1016/j.cattod.2016.10.029",
language = "English",
volume = "N/A",
journal = "Catalysis Today",
issn = "0920-5861",
publisher = "Elsevier",

}

Legionella jordanis inactivation in water by solar driven processes: EMA-qPCR versus culture-based analyses for new mechanistic insights. / Polo-López, María Inmaculada; Castro-Alférez, María; Nahim-Granados, Samira; Malato, Sixto; Fernandez-Ibanez, Pilar.

In: Catalysis Today, Vol. N/A, 23.10.2016.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Legionella jordanis inactivation in water by solar driven processes: EMA-qPCR versus culture-based analyses for new mechanistic insights

AU - Polo-López, María Inmaculada

AU - Castro-Alférez, María

AU - Nahim-Granados, Samira

AU - Malato, Sixto

AU - Fernandez-Ibanez, Pilar

PY - 2016/10/23

Y1 - 2016/10/23

N2 - In this contribution, the validation of EMA-qPCR method for the quantification of viable Legionella spp. in water after solar treatments was carried out. EMA-qPCR was used to evaluate the different effects of several solar water disinfection processes over this bacterium, and furthermore their mode of action. Inactivation of Legionella jordanis in water by solar photocatalytic (TiO2 and TiO2/H2O2) and solar photochemical (solar/H2O2 and solar disinfection) processes have been investigated under natural sunlight. Culture-based and molecular (EMA-qPCR) techniques were systematically compared for the analysis of treated water samples. Solar tests were done under natural solar radiation (clear sky) and ambient temperature (20–35 °C) for 2 h, using H2O2/Solar (10, 20 and 50 mg/L), TiO2/Solar (100, 200, 300, 400, and 500 mg/L) and TiO2/H2O2/Solar (100/10, 200/10, 500/10 mg/L). According to culture-based method, the best results of bacterial inactivation were obtained for 500/10 mg/L of TiO2/H2O2. The order of efficiency to reach complete inactivation was: TiO2/H2O2/solar (5 min) > TiO2/solar (15 min) ≈ H2O2/solar (15 min) > Solar only disinfection (90 min). Moreover, EMA-qPCR and culturable counting results showed a direct correlation for samples treated with TiO2/solar for those catalyst concentrations that generate a strong oxidative attack over the cell wall. EMA-qPCR results demonstrated to be a good method to detect damaged and dead cells when the treatment affects the integrity of the cell’s membrane, as occurs under photocatalysis. Meanwhile for solar disinfection and solar/H2O2 (at non-toxic concentrations,

AB - In this contribution, the validation of EMA-qPCR method for the quantification of viable Legionella spp. in water after solar treatments was carried out. EMA-qPCR was used to evaluate the different effects of several solar water disinfection processes over this bacterium, and furthermore their mode of action. Inactivation of Legionella jordanis in water by solar photocatalytic (TiO2 and TiO2/H2O2) and solar photochemical (solar/H2O2 and solar disinfection) processes have been investigated under natural sunlight. Culture-based and molecular (EMA-qPCR) techniques were systematically compared for the analysis of treated water samples. Solar tests were done under natural solar radiation (clear sky) and ambient temperature (20–35 °C) for 2 h, using H2O2/Solar (10, 20 and 50 mg/L), TiO2/Solar (100, 200, 300, 400, and 500 mg/L) and TiO2/H2O2/Solar (100/10, 200/10, 500/10 mg/L). According to culture-based method, the best results of bacterial inactivation were obtained for 500/10 mg/L of TiO2/H2O2. The order of efficiency to reach complete inactivation was: TiO2/H2O2/solar (5 min) > TiO2/solar (15 min) ≈ H2O2/solar (15 min) > Solar only disinfection (90 min). Moreover, EMA-qPCR and culturable counting results showed a direct correlation for samples treated with TiO2/solar for those catalyst concentrations that generate a strong oxidative attack over the cell wall. EMA-qPCR results demonstrated to be a good method to detect damaged and dead cells when the treatment affects the integrity of the cell’s membrane, as occurs under photocatalysis. Meanwhile for solar disinfection and solar/H2O2 (at non-toxic concentrations,

KW - EMA

KW - Legionella jordanis

KW - Real time qPCR

KW - TiO2

KW - Hydrogen peroxide

U2 - 10.1016/j.cattod.2016.10.029

DO - 10.1016/j.cattod.2016.10.029

M3 - Article

VL - N/A

JO - Catalysis Today

T2 - Catalysis Today

JF - Catalysis Today

SN - 0920-5861

ER -