Biological and chemical strategies for exploring inter- and intra-kingdom communication mediated via bacterial volatile signals

• Published in: Nature protocols Vol. 12; no. 7; pp. 1359 - 1377
• Main Authors: Farag, Mohamed A, Song, Geun Cheol, Park, Yong-Soon, Audrain, Bianca, Lee, Soohyun, Ghigo, Jean-Marc, Kloepper, Joseph W, Ryu, Choong-Min
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-07-2017; Nature Publishing Group
• Subjects: 631/158/2463; 631/158/853; 631/1647/2196/1379; 631/1647/2196/2111; 631/1647/2234; Air flow; Air pollution; Allelochemicals; Analytical Chemistry; Arabidopsis; Arabidopsis - microbiology; Bacteria; Bacteria - metabolism; Biochemistry, Molecular Biology; Biological products; Biological Techniques; Compartments; Computational Biology/Bioinformatics; Headspace; Host-bacteria relationships; Host-Pathogen Interactions; In vitro methods and tests; Life Sciences; Metabolites; Microarrays; Microbial Interactions; Nicotiana - microbiology; Organic Chemistry; Plants (botany); protocol; Seedlings; Solid phase methods; Solid phases; Strains (organisms); Testing; Tobacco; Volatile compounds; Volatile Organic Compounds; Volatile Organic Compounds - metabolism; Volatiles; Solid-phase microextraction; Gas chromatography; Community ecology; Microbiology techniques; Ecological networks
• ISSN: 1754-2189; 1750-2799; 1750-2799
• DOI: 10.1038/nprot.2017.023

Bacterial interactions with other species can occur via small, volatile metabolites. In this protocol, volatile metabolites generated by placing two species in a two-Petri-plate system are analyzed by GC–MS after solid-phase microextraction.
Airborne chemical signals emitted by bacteria influence the behavior of other bacteria and plants. We present an overview of
in vitro
methods for evaluating bacterial and plant responses to bacterial volatile compounds (BVCs). Three types of equipment have been used to physically separate the bacterial test strains from either other bacterial strains or plants (in our laboratory we use either
Arabidopsis
or tobacco plant seedlings): a Petri dish containing two compartments (BI Petri dish); two Petri dishes connected with tubing; and a microtiter-based assay. The optimized procedure for the BI Petri dish system is described in this protocol and can be widely used for elucidation of potential function in interactions between diverse microbes and those plant and chemical volatiles emitted by bacteria that are most likely to mediate bacterial or plant responses to BVCs. We also describe a procedure for metabolome-based BVC profiling via dynamic (i.e., continuous airflow) or static headspace sampling using solid-phase microextraction (SPME). Using both these procedures, bacteria–bacteria communications and bacteria–plant interactions mediated by BVCs can be rapidly investigated (within 1–4 weeks).