Bacterial volatiles and their action potential

Abstract

During the past few years, an increasing awareness concerning the emission of an unexpected high number of bacterial volatiles has been registered. Humans sense, intensively and continuously, microbial volatiles that are released during food transformation and fermentation, e.g., the aroma of wine and cheese. Recent investigations have clearly demonstrated that bacteria also employ their volatiles during interactions with other organisms in order to influence populations and communities. This review summarizes the presently known bioactive compounds and lists the wide panoply of effects possessed by organisms such as fungi, plants, animals, and bacteria. Because bacteria often emit highly complex volatile mixtures, the determination of biologically relevant volatiles remains in its infancy. Part of the future goal is to unravel the structure of these volatiles and their biosynthesis. Nevertheless, bacterial volatiles represent a source for new natural compounds that are interesting for man, since they can be used, for example, to improve human health or to increase the productivity of agricultural products.

Substrate-induced volatile organic compound emissions from compost-amended soils

“…Along with plant roots, microorganisms have been reported to be a major source of VOCs produced in soils (Stotzky and Schenk 1976;Stahl and Parkin 1996;Mackie and Wheatley 1999;Isidorov and Jdanova 2002;Leff and Fierer 2008;Kai et al 2009;Insam and Seewald 2010). In contrast to this and despite microbial VOC production, plain soil (without plant roots) is reported to be a VOC sink, strongly dependent on soil temperature and moisture (Asensio et al 2007a).…”

Volatile affairs in microbial interactions

“…Currently, most studies on microbial volatiles are performed in vitro under nutrient rich conditions (Kai et al, 2009;Weise et al, 2012) and may not represent the conditions that prevail in the microbial environment. Furthermore, as indicated by Garbeva et al (2014a,b), the composition of volatiles produced by a mixture of bacterial species can differ from those produced by each bacterial monoculture.…”

“…Sensitivity to volatiles can strongly differ between fungal species and the extent of inhibition depends on the individual bacteria-fungus or fungus-fungus interaction (Kai et al, , 2009Vespermann et al, 2007;Garbeva et al, 2014b). Several independent studies have reported that F. solani is not much affected by bacterial volatiles, whereas Pythium species (oomycetes) are highly sensitive to bacterial volatiles (Kai et al, 2009;Effmert et al, 2012;Garbeva et al, 2014a,b).…”

“…Several independent studies have reported that F. solani is not much affected by bacterial volatiles, whereas Pythium species (oomycetes) are highly sensitive to bacterial volatiles (Kai et al, 2009;Effmert et al, 2012;Garbeva et al, 2014a,b). F. oxysporum was also reported to be rather resistant to volatiles produced , aldehydes (for example, benzaldehyde), alkanes (for example, undecane), alkenes (1-undecene), aromatic compounds (for example, 2-phenylethanol), esters (for example, 2-phenylethyl ester), fatty acids (for example, butyric acid), isoprene, lactic acid, lactones (for example, gammabutyrolactone), methylketones (for example, acetone), monoterpenes (for example, farnesol), nitrogen compounds (for example, benzonitrile), sesquiterpenes (for example, pinene) and sulphur compounds (for example, dimethyl disulphide).…”

“…Furthermore, exposure to bacterial volatiles has been reported to change fungal morphology, enzyme activity and gene expression (Wheatley, 2002;Vespermann et al, 2007;Minerdi et al, 2008Minerdi et al, , 2009Kai et al, 2009;Garbeva et al, 2011Garbeva et al, , 2014b. For example, activity of laccases and tyrosinases can be strongly affected by bacterial volatiles (Wheatley, 2002).…”