Botrytis cinerea infection in tomato leaves triggers changes in root volatilome and microbiome, revealing connections between aboveground infections and un

Published in Foods (Basel, Switzerland)

Botrytis cinerea infection in tomato leaves triggers changes in root volatilome and microbiome, revealing connections between aboveground infections and un

Context Volatile organic compounds (VOCs) create invisible chemical landscapes that influence ecosystem processes. Yet whether VOC β-diversity (i.e., variability in VOC composition between patches) responds to structural heterogeneity and reflects silvicultural habitat management remains unclear. Objectives In a large field experiment, we quantified how enhanced structural beta complexity (ESBC) affects VOC β-diversity patterns and investigated potential drivers and ecological effects in temperate production forests. Methods We sampled VOCs in ambient forest air using Tenax/Carboxen adsorbent traps at forest floor and 1 m heights across 234 treatment and control forest patches in six German regions. We analyzed VOCs via thermal desorption-gas chromatography mass-spectrometry (TD-GCMS) and examined environmental drivers including deadwood characteristics, canopy cover, tree species dissimilarity, and herb layer dissimilarity. We tested potential ecological relevance by analyzing saproxylic beetle community responses. Results VOC β-diversity increased significantly at 1 m height in heterogeneous forests compared to homogeneous forests, but we found no significant change at the forest floor. Deadwood volume and deadwood structural diversity, rather than canopy openness, were identified as the main drivers of increasing VOC β-diversity. Dissimilarity in beetle community composition was associated with VOC β-diversity, but only for forest floor VOCs, suggesting these chemical patterns may correlate with variables beetles respond to. Conclusions Our findings suggest that volatile β-diversity represents an overlooked dimension of habitat heterogeneity, one that creates invisible chemical heterogeneity influencing inter- and intra-species interactions and ecosystem processes. We demonstrate that enhancing forest heterogeneity through deadwood retention increases both structural heterogeneity and volatile β-diversity.

npj Parkinson's Disease - Classification of Parkinson’s disease and isolated REM sleep behaviour disorder: delineating progression markers from the sebum volatilome

Hernandez-Leyva et al. show that gut bacteria influence the volatile organic compounds found in exhaled in host breath. Future breath-based diagnostics leveraging this relationship may offer a rapid and accessible view of the health of the gut microbiome.

Bacillus subtilis is one of the best-studied organisms and of high importance in biotechnology. Depending on the application area, the bacterium encou…

The gut microbiota is crucial to health, yet implementation of microbiota-based therapeutics is limited by the lack of rapid diagnostics. We hypothesi…

npj Parkinson's Disease - Classification of Parkinson’s disease and isolated REM sleep behaviour disorder: delineating progression markers from the sebum volatilome

Microbial metabolic functions are increasingly conceptualized as fitness-regulating traits. However, volatile compounds (the volatilome), despite their key roles in metabolism and ecology, are often overlooked in trait-based frameworks. We propose that volatile traits not only reflect ecological strategies but also shape them by mediating responses to selection pressures. Their volatility affects diffusion, substrate access, and interactions across space, conferring selective advantages as resources or waste products. We outline approaches to incorporate volatile traits into predictive models to improve understanding of microbial selection and community dynamics. This integration enables a more holistic view of microbial life by accounting for the ecological and evolutionary consequences of volatile-mediated processes.

This study aimed at elucidating the impact of high-intensity ultrasonication (HIU) on milk’s aromatic profile and the molecular interaction behaviors between aroma compounds and β-lactoglobulin (BLG) through nontargeted headspace-gas chromatography–ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction gas chromatography/mass spectrometry (HS-SPME-GC/MS), as well as targeted multispectral characterization. GC-IMS effectively distinguished different milk dispersions with and without HIU pretreatments based on the volatile patterns, complemented by HS-SPME-GC/MS for precise classification based on its high sensitivity to detect aroma compounds, simultaneously revealing the significant effects on the evolution of volatile flavor compounds in milk suspensions after nonthermal HIU treatments. Principal component analysis (PCA) of GC-IMS data showed clear separation between all milk samples and controls with 20 min HIU. Additionally, the unbound fraction of hexanal in the headspace decreased by 12% following BLG addition. Conformational changes in BLG induced by HIU, showing more subtle structural transformation compared to thermal pretreatments, significantly altered the interaction processes between proteins and volatile flavors, thus explaining the fluctuation in the contents of headspace aldehyde-ketones following HIU pretreatments of milk suspensions. Molecular docking confirmed the binding between BLG and volatile ligands, highlighting the protein’s role in flavor retention and release. The combined volatilomic and protein-structure approaches emphasized specific effects of HIU on the aroma profiling of dairy products and molecular structure of their proteins under cold sterilization conditions, providing new insights into flavor optimization and preservation.

Volatile organic compounds (VOCs) in urine have shown increasing promise as non-invasive biomarkers for the early detection and monitoring of diseases. However, their volatile nature may make them highly susceptible to pre-analytical factors, presenting significant challenges for consistent biomarker discovery and reproducibility within metabolomic workflows. This study aimed to assess the impact of four critical pre-analytical variables, including fasting state, centrifugation procedures, room temperature (RT) stability, and freeze-thaw (FT) cycles, as well as intra- and inter-individual variability on the profiles of urinary VOC in general and volatile carbonyl compounds (VCC), in particular. Urine samples were analysed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME/GC-MS). Our findings demonstrate that, although multivariate analysis did not discriminate between fasting and non-fasting states, univariate analysis revealed that the levels of distinct VOCs and VCCs significantly differed between both states. The urinary VOC or VCC profiles were very similar under both standard centrifugation and sequential mild pre-centrifugation followed by ultracentrifugation. These findings suggest that supernatants obtained from assays involving ultracentrifugation are suitable for volatilome analysis. RT stability studies demonstrated that VOC profiles remain stable for up to 21 h at RT, whereas VCC profiles showed alterations after 14 h. Compound-specific variations were also observed following repeated FT cycles, with several VOCs disclosing significant changes after two cycles, while VCC profiles remained stable, with no significant alterations detected. Both intra- and inter-individual variability were high, as evidenced by relative standard deviations exceeding 30% for most compounds and intraclass correlation coefficients below 0.4, indicating limited temporal reliability over a 2.5-month period with eight timepoint collections. These findings underscore the essential role of pre-analytical standardization in urinary volatile analysis and support the implementation of rigorous protocols to enhance data reproducibility and biomarker discovery in metabolomics. Graphical abstract

Published in Molecules (Basel, Switzerland)

Billy, a floppy-eared little beagle, darts around a platform sniffing a series of holes. Cancer can change a person’s “volatilome,” the unique set of volatile organic compounds found in breath, sweat...