AHL-lactonase characteristics of Bacillus thuringiensis SGT3g and its effectiveness in inhibiting pathogenicity of Dickeya dadantii
- Author:
Putri Eka Sari
;
Iman Rusmana
;
Alina Akhdiya
- Publication Type:Journal Article
- Keywords:
AHL-degradation;
Bacillus thuringiensis;
Phalaenopsis;
quorum sensing;
quorum quenching
- MeSH:
Bacillus thuringiensis
- From:Malaysian Journal of Microbiology
2016;12(4):315-321
- CountryMalaysia
- Language:English
-
Abstract:
ABSTRACT
Aims: Dickeya dadantii is a pathogenic bacterium causing bacterial soft rot disease in plants. The bacterium uses a
homoserine lactone signal in its quorum sensing process to express the virulence factor genes. Anti-quorum sensing is a
new approach to control plant pathogenic bacteria. The aims of this study are to characterize AHL-lactonase enzyme
produced by Bacillus thuringiensis SGT3g and to determine its effectiveness in inhibiting virulence of D. dadantii.
Methodology and results: Activity of AHL-lactonase was determined using Chromobacterium violaceum as a bacterial
biosensor. The crude extract enzymes of AHL-lactonase on both as extracellular and intracellular enzymes were
analyzed their enzyme activity of protein precipitation and dialysis products. The optimum activity of AHL-lactonase was
found at 30 °C and pH 5-8. Bacillus thuringiensis SGT3g was capable to reduce soft rot symptom disease caused by D.
dadantii on Phalaenopsis orchid leaves after 24 h of incubation.
Conclusion, significance and impact study: Bacillus thuringiensis SGT3g was capable to degrade AHL signal of C.
violaceum and D. dadantii. The activity AHL-lactonase of B. thuringiensis SGT3g had a wide range of pH and
temperature. The lactonase could reduce soft rot symptom disease caused by D. dadantii without any growth inhibition
of D. dadantii on orchid leaves. Bacillus thuringiensis SGT3g can be used as an alternative biopesticide to control
phytopathogenic bacteria due to its capability to suppress bacterial pathogenic virulence.
- Full text:P020170105548946361368.pdf
