Pest Management Science (2017) 73, 568-574

Olfa Frikha-Gargouri, Dorra Ben Abdallah, Imen Ghorbel, Ikram Charfeddine, Lobna Jlaiel, Mohamed Ali Triki and Slim Tounsi (2017)
Lipopeptides from a novel Bacillus methylotrophicus 39b strain suppress Agrobacterium crown gall tumours on tomato plants
Pest Management Science 73 (3), 568-574
Abstract:
BACKGROUND
This study aims to characterise the antibacterial activity of a novel Bacillus methylotrophicus strain named 39b against tumourigenic Agrobacterium tumefaciens C58 and B6 strains. It also aims to identify the compound that is responsible for its activity and to evaluate its efficiency to control crown gall disease in tomato plants.
RESULTS
B. methylotrophicus strain 39b was found to stop the growth of phytopathogenic A. tumefaciens strains in in vitro experiments. Lipopeptides – surfactins, iturins and fengycins – were detected under various isoforms by mass spectrometry analysis of the methanolic extract. The active principle acting against Agrobacterium strains was isolated from TLC plates and identified by mass spectrometry as surfactin. The strain was effective in reducing the weight and the number of galls induced by A. tumefaciens strains on tomato plants. Total inhibition of gall formation was observed using the antibacterial compounds.
CONCLUSION
B. methylotrophicus strain 39b exhibited antibacterial activity against phytopathogenic A. tumefaciens C58 and B6 both in vitro and in vivo. Lipopeptides are the main compounds that confer the biocontrol ability. This strain has the potential to be developed as a biological control agent for crown gall disease.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Slim Tounsi

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Rhizobium radiobacter	Tomato (Solanum lycopersicum)
Bacillus methylotrophicus (antagonist)	Rhizobium radiobacter	Tomato (Solanum lycopersicum)