Isolation and characterization of chemical constituents from B. amyloliquefaciens and their nematicidal activity

Abstract

Secondary metabolites from cell free culture filtrate of B. amyloliquefaciens (Ba-14.5) showed strong nematicidal activity against root-knot nematode in preliminary tests. In the present study, chemical constituents present in secondary metabolites of B. amyloliquefaciens were investigated. Methanol fractions obtained from silica gel chromatography were analysed by using GC-MS. Thirteen compounds were revealed by GC-MS analysis and these constituents include stigmasta-3,5-dien-7-one (9.82%), Pregna-5, 16-dien-20-one, 3-(acetyloxy)-,(3.beta)-(5.12%), Benzeneacetaldehyde (3.96%), N-acetyl-3-methyl-1, 4-diazabicyclo[4.3.0]nonan-2,5-dione (3.65%), Pyrrolo (1,2-1) pyrazine-1,4-dione,hexahydro-(39.57%), 2,4,6,8-Tetramethyldecan-1-ol (0.54%), Pyrrolo (1,2-1) pyrazine-1,4-dione, hexahydro-3-(2-methylpropyl)- (4.96%), Hexadecanoic acid, methyl ester (0.35%), 5, 10-Diethoxy-2,3,7,8-tetrahydro-1H, 6H-dipyrrolo(1,2-a (1.35%), n-Octadecanoic acid methyl ester (0.39%), 3,6-Disobutyl-2,5-Piperazinedione (4.21%), Hexadecanoic acid, 2-hydroxy-1-(hydroxymethyl)ethyl ester (9.7%), and Octadecanoic acid, 2,3-dihydroxypropyl ester (21.8%). Among thirteen compounds, three compounds like Benzeneacetaldehyde, 2-hydroxy-1-(hydroxymethyl) ethyl ester and Octadecanoic acid, 2,3-dihydroxypropyl ester possess nematicidal activity based on previous studies. Other compounds possess antimicrobial, antifungal, antioxidant, anticancer and insecticidal properties and are yet to be confirmed for their nematicidal activity. Our findings help to find potential compounds/metabolites from microbial source to develop nematicides for the management of root-knot nematode in horticultural crops.