Nematicidal activity of volatile organic compounds produced by Bacillus altitudinis AMCC 1040 against Meloidogyne incognita

The application of nematicidal microorganisms and their virulence factors provides more opportunities to control root-knot nematodes. Bacillus altitudinis AMCC 1040, previously isolated from suppressive soils, showed significant nematicidal activity, and in this study, nematicidal substances produced by Bacillus altitudinis AMCC 1040 were investigated. The results of the basic properties of active substances showed that these compounds have good thermal stability and passage, are resistant to acidic environment and sensitive to alkaline conditions. Further analysis showed that it is a volatile component. Using HS-SPME-GC/MS, the volatile compounds produced by Bacillus altitudinis AMCC 1040 were identified and grouped into four major categories: ethers, alcohols, ketone, and organic acids, comprising a total of eight molecules. Six of them possess nematicidal activities, including 2,3-butanedione, acetic acid, 2-isopropoxy ethylamine, 3-methylbutyric acid, 2-methylbutyric acid and octanoic acid. Our results further our understanding of the effects of Bacillus altitudinis and its nematicidal metabolites on the management of Meloidogyne incognita and may help in finding less toxic nematicides to control root knot nematodes.