A comparison of collection methods for microbial volatiles

Authors: Rering, Caitlin; Gaffke, Alexander; Rudolph, Arthur; Beck, John; Alborn, Hans

Submitted to: Frontiers in Sustainable Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/19/2020
Publication Date: 12/11/2020
Citation: Rering, C.C., Gaffke, A.M., Rudolph, A.B., Beck, J.J., Alborn, H.T. 2020. A comparison of collection methods for microbial volatiles. Frontiers in Sustainable Food Systems. 4:598967. https://doi.org/10.3389/fsufs.2020.598967.
DOI: https://doi.org/10.3389/fsufs.2020.598967

Interpretive Summary: Microorganisms such as fungi and bacteria are important to the health of plants and animals. The odors that microorganisms produce can have important effects on plant's health, disease, growth, among other impacts. However, research into the odors produced by microorganisms is still limited, and many different methods are used, some of which may not capture odors as well as others. ARS Scientists at the Center for Medical, Agricultural, and Veterinary Entomology, in Gainesville, FL evaluated the efficiency of three odor collection methods to ascertain the most optimal method for odor identification. The relative performance and pros and cons of each method are discussed. Knowledge and the identities of the odors emitted by microorganisms help ARS scientists develop effective control measures for insect pests, or increase the health of beneficial insects of important agricultural commodities.

Technical Abstract: Accurate collection and analysis of volatile profiles from various organisms is a critical step in investigations of inter-organismal chemical communication. Recently, there has been an increase in the number of reports that highlight the role of microbes and their volatile metabolites in interactions with plants and insects, including interactions which may benefit agricultural production. Accordingly, accurate detection and authentication of volatiles emitted from microbe-inoculated media is a research priority. Though numerous volatile organic compounds are emitted from plants, insects, and microbes, emissions from microbes typically contain unique polar, compounds of high volatility; thus, commonly used plant or insect collection techniques may not give an accurate representation of microbe specific volatile profiles. Here, we present and compare the volatile data derived via three solventless collection techniques: direct headspace injection, solid-phase microextraction, and active sampling with a sorptive matrix. These methods were applied to a synthetic floral nectar media containing a nectar-inhabiting yeast, Metschnikowia reukaufii, and sunflower (Helianthus annus) pollen.