Identification of Orfamide A as an Insecticidal Metabolite Produced by Pseudomonas protegens F6

Abstract

The use of biosurfactants for agricultural crop protection has been gaining interest because they are generally biodegradable and environmentally friendly. In the present study, we identified an insecticidal biosurfactant produced by Pseudomonas protegens F6 (F6) and examined its use for aphid control. The growth of F6 was accompanied by increased aphid mortality and decreased water surface tension. Bioassay-guided chromatography coupled with instrumental analyses, nuclear magnetic resonance (NMR), and time-of-flight mass spectrometer (TOF MS) identified orfamide A as a major metabolite that showed insecticidal activity against green peach aphid ( Myzus persicae ). Orfamide A revealed a dose-dependent mortality against aphids, producing a LC50 value at 34.5 μg/mL, and caused a considerable decrease in the surface tension value of water, giving about 35.7 mN/m at 10 μg/mL. Laboratory and greenhouse mortality bioassays suggested that orfamide A may be applicable to control aphids in organic agriculture. This is the first report of orfamide A as an insecticidal metabolite against Myzus persicae .

Comparison on kinetics and microbial community among denitrification process fed by different kinds of volatile fatty acids

“…N2 (Pseudomonas protegens) is known as an acetate using denitrifier [29], which agreed with its exclusive enrichment in acetic acid lane.…”

Characterization of Toxin Complex Gene Clusters and Insect Toxicity of Bacteria Representing Four Subgroups of Pseudomonas fluorescens

“…Rhizoxin is a 16-member macrolide that binds to β-tubulin, thereby interfering with microtubule dynamics during mitosis, and is toxic to many eukaryotes [41]. Orfamide A is a cyclic lipopeptide with surfactant properties that aids in bacterial motility across surfaces and solubilization of certain substrates [42], inhibition of some oomycetes and fungi [42,43,44], and toxicity to the green peach aphid [45]. Chitinases can degrade the peritrophic membrane, a chitin-based matrix in the insect mid-gut that functions in protection against mechanical and chemical damage and serves as a barrier to infection by pathogens [46].…”

Insect pathogenicity in plant-beneficial pseudomonads: phylogenetic distribution and comparative genomics

“…However, some have activity against a broad spectrum of organisms including plants, nematodes, arthropods and even mammalian cells (Maurhofer et al, 1992;Devi and Kothamasi, 2009;Kwak et al, 2011;Neidig et al, 2011;Nisr et al, 2011;Jang et al, 2013) and thus could contribute to Pseudomonas-derived insecticidal activity.…”