TY - JOUR

T1 - The quorum sensing luxS gene is induced in Lactobacillus acidophilus NCFM in response to Listeria monocytogenes

AU - Moslehi Jenabian, Saloomeh

AU - Vogensen, Finn Kvist

AU - Jespersen, Lene

PY - 2011

Y1 - 2011

N2 - The luxS gene involved in quorum sensing has been shown to control different behaviour of probiotic lactobacilli. In this study we investigated if luxS in Lactobacillus acidophilus NCFM was up-regulated in response to Listeria monocytogenes EGD-e. The two bacterial strains were grown in mono- and co-culture and the growth of both bacteria and the transcriptional level of luxS in L. acidophilus cells were monitored. Contrary to L. acidophilus, the growth of L. monocytogenes was significantly affected by co-cultivation. Transcriptional analysis showed that the expression of luxS increased during exponential growth in L. acidophilus cells with the highest level in the late-exponential growth phase, decreasing in the stationary phase. Following co-cultivation with L. monocytogenes, the transcriptional level of luxS increased significantly in mid-exponential growing cells of L. acidophilus after incubation with viable L. monocytogenes cells and by addition of cell-free culture supernatant of L. monocytogenes, whereas incubation with heat killed cells of L. monocytogenes had no effect on the transcriptional level. This could indicate that the up-regulation of luxS is due to a response to a secreted compound produced by L. monocytogenes cells. Highlights ¿ luxS is in L. acidophilus up-regulated in response to L. monocytogenes. ¿ Viable L. monocytogenes cells significantly affect luxS transcription. ¿ Culture supernatant of L. monocytogenes significantly affects luxS transcription. ¿ Heat-killed cells of L. monocytogenes have no effect on luxS transcription. The luxS gene involved in quorum sensing has been shown to control different behaviour of probiotic lactobacilli. In this study we investigated if luxS in Lactobacillus acidophilus NCFM was up-regulated in response to Listeria monocytogenes EGD-e. The two bacterial strains were grown in mono- and co-culture and the growth of both bacteria and the transcriptional level of luxS in L. acidophilus cells were monitored. Contrary to L. acidophilus, the growth of L. monocytogenes was significantly affected by co-cultivation. Transcriptional analysis showed that the expression of luxS increased during exponential growth in L. acidophilus cells with the highest level in the late-exponential growth phase, decreasing in the stationary phase. Following co-cultivation with L. monocytogenes, the transcriptional level of luxS increased significantly in mid-exponential growing cells of L. acidophilus after incubation with viable L. monocytogenes cells and by addition of cell-free culture supernatant of L. monocytogenes, whereas incubation with heat killed cells of L. monocytogenes had no effect on the transcriptional level. This could indicate that the up-regulation of luxS is due to a response to a secreted compound produced by L. monocytogenes cells. Highlights ¿ luxS is in L. acidophilus up-regulated in response to L. monocytogenes. ¿ Viable L. monocytogenes cells significantly affect luxS transcription. ¿ Culture supernatant of L. monocytogenes significantly affects luxS transcription. ¿ Heat-killed cells of L. monocytogenes have no effect on luxS transcription.

AB - The luxS gene involved in quorum sensing has been shown to control different behaviour of probiotic lactobacilli. In this study we investigated if luxS in Lactobacillus acidophilus NCFM was up-regulated in response to Listeria monocytogenes EGD-e. The two bacterial strains were grown in mono- and co-culture and the growth of both bacteria and the transcriptional level of luxS in L. acidophilus cells were monitored. Contrary to L. acidophilus, the growth of L. monocytogenes was significantly affected by co-cultivation. Transcriptional analysis showed that the expression of luxS increased during exponential growth in L. acidophilus cells with the highest level in the late-exponential growth phase, decreasing in the stationary phase. Following co-cultivation with L. monocytogenes, the transcriptional level of luxS increased significantly in mid-exponential growing cells of L. acidophilus after incubation with viable L. monocytogenes cells and by addition of cell-free culture supernatant of L. monocytogenes, whereas incubation with heat killed cells of L. monocytogenes had no effect on the transcriptional level. This could indicate that the up-regulation of luxS is due to a response to a secreted compound produced by L. monocytogenes cells. Highlights ¿ luxS is in L. acidophilus up-regulated in response to L. monocytogenes. ¿ Viable L. monocytogenes cells significantly affect luxS transcription. ¿ Culture supernatant of L. monocytogenes significantly affects luxS transcription. ¿ Heat-killed cells of L. monocytogenes have no effect on luxS transcription. The luxS gene involved in quorum sensing has been shown to control different behaviour of probiotic lactobacilli. In this study we investigated if luxS in Lactobacillus acidophilus NCFM was up-regulated in response to Listeria monocytogenes EGD-e. The two bacterial strains were grown in mono- and co-culture and the growth of both bacteria and the transcriptional level of luxS in L. acidophilus cells were monitored. Contrary to L. acidophilus, the growth of L. monocytogenes was significantly affected by co-cultivation. Transcriptional analysis showed that the expression of luxS increased during exponential growth in L. acidophilus cells with the highest level in the late-exponential growth phase, decreasing in the stationary phase. Following co-cultivation with L. monocytogenes, the transcriptional level of luxS increased significantly in mid-exponential growing cells of L. acidophilus after incubation with viable L. monocytogenes cells and by addition of cell-free culture supernatant of L. monocytogenes, whereas incubation with heat killed cells of L. monocytogenes had no effect on the transcriptional level. This could indicate that the up-regulation of luxS is due to a response to a secreted compound produced by L. monocytogenes cells. Highlights ¿ luxS is in L. acidophilus up-regulated in response to L. monocytogenes. ¿ Viable L. monocytogenes cells significantly affect luxS transcription. ¿ Culture supernatant of L. monocytogenes significantly affects luxS transcription. ¿ Heat-killed cells of L. monocytogenes have no effect on luxS transcription.

KW - Former LIFE faculty

KW - Probiotics

KW - Lactobacillus acidophilus NCFM

KW - Quorum sensing

KW - Cell-Cell communication

KW - luzs and listeria monocytogenes

U2 - 10.1016/j.ijfoodmicro.2011.06.011

DO - 10.1016/j.ijfoodmicro.2011.06.011

M3 - Journal article

C2 - 21784546

VL - 149

SP - 269

EP - 273

JO - International Journal of Food Microbiology

JF - International Journal of Food Microbiology

SN - 0168-1605

IS - 3

ER -