Inhibitory and Toxic Effects of Volatiles Emitted by Strains ofPseudomonasandSerratiaon Growth and Survival of Selected Microorganisms,Caenorhabditis elegans, andDrosophila melanogaster

Abstract

In previous research, volatile organic compounds (VOCs) emitted by various bacteria into the chemosphere were suggested to play a significant role in the antagonistic interactions between microorganisms occupying the same ecological niche and between bacteria and target eukaryotes. Moreover, a number of volatiles released by bacteria were reported to suppress quorum-sensing cell-to-cell communication in bacteria, and to stimulate plant growth. Here, volatiles produced by Pseudomonas and Serratia strains isolated mainly from the soil or rhizosphere exhibited bacteriostatic action on phytopathogenic Agrobacterium tumefaciens and fungi and demonstrated a killing effect on cyanobacteria, flies (Drosophila melanogaster), and nematodes (Caenorhabditis elegans). VOCs emitted by the rhizospheric Pseudomonas chlororaphis strain 449 and by Serratia proteamaculans strain 94 isolated from spoiled meat were identified using gas chromatography-mass spectrometry analysis, and the effects of the main headspace compounds—ketones (2-nonanone, 2-heptanone, 2-undecanone) and dimethyl disulfide—were inhibitory toward the tested microorganisms, nematodes, and flies. The data confirmed the role of bacterial volatiles as important compounds involved in interactions between organisms under natural ecological conditions.

The chemical ecology of the fly

“…This compound is also a mosquito repellent [43], but what precisely 2-nonanone signifyto flies or mosquitoes -is unclear. 2-Nonaone is, however, unlike geosmin in itself toxic to flies [44]. Or45a might hence serve to signal the presence of a harmful chemical, rather than the presence of a specific harmful microbe.…”

Inhibition of cyanobacterial photosynthetic activity by natural ketones

“…), suppress the development of different invertebrates, fungi and bacteria (Popova et al. ), and affect bacterial Quorum sensing systems (Plyuta et al. ) and bacteria biofilms (Plyuta et al.…”

Untitled

“…They are competitive colonizers of the rhizosphere of various crop plants and have broad spectrum antagonistic activity against plant pathogens [10][11][12][13][14] . Some species of Pseudomonas can also produce levels of hydrogen cyanide that are toxic to certain pathogenic microorganisms 15 . The antibacterial effects against Xanthomonas citri pv.…”