ESR spin trapping for characterization of radical formation in Lactobacillus acidophilus NCFM and Listeria innocua

TY - JOUR

T1 - ESR spin trapping for characterization of radical formation in Lactobacillus acidophilus NCFM and Listeria innocua

AU - Hougaard, Anni Bygvrå

AU - Arneborg, Nils

AU - Andersen, Mogens Larsen

AU - Skibsted, Leif Horsfelt

PY - 2013/9

Y1 - 2013/9

N2 - In this study, radicals in pure cultures of Lactobacillus acidophilus NCFM and Listeria innocua were detected in a quantitative way by electron spin resonance spectroscopy using spin trapping with 5,5-dimethyl-1-pyrroline-. N-oxide (DMPO) or N-tert-butyl-α-phenylnitrone (PBN). No adverse effect of spin trap addition on viability was observed for any of the bacterial strains. L. acidophilus NCFM had a higher production of radicals than L. innocua when incubated in a growth medium. Furthermore, by using DMPO in a buffer system, the radicals produced by L. acidophilus NCFM could be identified as hydroxyl radicals. The presence of polyethylene glycol, impermeable for bacterial cells, decreased the signal intensity of the ESR spectrum of the DMPO-OH adduct in cultures of L. acidophilus NCFM and indicated quenching of hydroxyl radicals outside the bacteria. This suggests that radical production is an extracellular event for L. acidophilus NCFM.

AB - In this study, radicals in pure cultures of Lactobacillus acidophilus NCFM and Listeria innocua were detected in a quantitative way by electron spin resonance spectroscopy using spin trapping with 5,5-dimethyl-1-pyrroline-. N-oxide (DMPO) or N-tert-butyl-α-phenylnitrone (PBN). No adverse effect of spin trap addition on viability was observed for any of the bacterial strains. L. acidophilus NCFM had a higher production of radicals than L. innocua when incubated in a growth medium. Furthermore, by using DMPO in a buffer system, the radicals produced by L. acidophilus NCFM could be identified as hydroxyl radicals. The presence of polyethylene glycol, impermeable for bacterial cells, decreased the signal intensity of the ESR spectrum of the DMPO-OH adduct in cultures of L. acidophilus NCFM and indicated quenching of hydroxyl radicals outside the bacteria. This suggests that radical production is an extracellular event for L. acidophilus NCFM.

U2 - 10.1016/j.mimet.2013.06.010

DO - 10.1016/j.mimet.2013.06.010

M3 - Journal article

C2 - 23811362

SN - 0167-7012

VL - 94

SP - 205

EP - 212

JO - Journal of Microbiological Methods

JF - Journal of Microbiological Methods

IS - 3

ER -