Detection and characterization of the novel bacteriocin entomocin 9, and safety evaluation of its producer, Bacillus thuringiensis ssp. entomocidus HD9
Articolo
Data di Pubblicazione:
2003
Citazione:
Detection and characterization of the novel bacteriocin
entomocin 9, and safety evaluation of its producer, Bacillus
thuringiensis ssp. entomocidus HD9 / A. Cherif, S. Chehimi, F. Limem, B.M. Hansen, N.B. Hendriksen, D. Daffonchio,
A. Boudabous. - In: JOURNAL OF APPLIED MICROBIOLOGY. - ISSN 1364-5072. - 95:5(2003), pp. 990-1000.
Abstract:
Aims: To identify and characterize new bacteriocins from a collection of 41 strains belonging to 27 subspecies of
Bacillus thuringiensis, and to evaluate the safety of the producers.
Methods and Results: Bacillus thuringiensis ssp. entomocidus HD9 produced in the culture supernatant an
antimicrobial activity against Gram-positive bacteria including Listeria monocytogenes, one of four pathogenic
Pseudomonas aeruginosa and several fungi. Production of the antibacterial activity, named entomocin 9, started
during mid-logarithmic growth reaching its maximum at the early stationary phase. Entomocin 9 retained more than
72% of activity after incubation for 20 min at 121 C. Activity was lost after proteinase K treatment, it was stable in
a pH range between 3 and 9, and resistant to lyophilization. After partial purification with ammonium sulphate
precipitation followed by gel-filtration and anion-exchange chromatography, an active protein of ca 12.4 kDa was
isolated. The mode of action of entomocin 9 was bactericidal and caused cell lysis of growing cells. Despite the
presence of a range of virulence related genes, including haemolysin BL, nonhaemolytic enterotoxin, cytotoxin K
and several hydrolytic activities, B. thuringiensis HD9 was not toxic against Vero cells.
Conclusions: Entomocin 9 is a novel heat-stable, bacteriocin produced by B. thuringiensis HD9. The absence of
toxicity against Vero cells suggests the suitability of strain HD9 for a safe application in antimicrobial treatments.
Significance and Impact of the Study: New finding on entomocin 9 would make B. thuringiensis attractive in
biotechnological applications as an antimicrobial agent in agriculture and food industry.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Bacillus thuringiensis safety evaluation, B. thuringiensis entomocidus, bacteriocins, characterization,
entomocin 9, partial purification, Vero cell assay.
Elenco autori:
A. Cherif, S. Chehimi, F. Limem, B.M. Hansen, N.B. Hendriksen, D. Daffonchio,
A. Boudabous
Link alla scheda completa: