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| Morphological changes in Phoma sp. (A-C), Colletotrichum sp. (D-F), Coleophoma sp. (G-I) and Phytophthora cinnamomi (J-L), by bVOCs produced by C. vaccinii MWU328. The column ADGJ represents untreated hyphae for each of the fungi. Columns BEHK and CFIL show hyphae from each of the fungi after exposure to bVOCs. (B,D,G,K) Are shown at 40x magnification, and (A,C,E,F,H,I,J, L) are shown at 100x.
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The study of chemical bioactivity in the rhizosphere has recently broadened to include microbial metabolites, and their roles in niche construction and competition via growth promotion, growth inhibition, and toxicity. Several prior studies have identified bacteria that produce volatile organic compounds (VOCs) with antifungal activities, indicatin...
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... deformations have previously been observed in phytopathogenic fungi exposed to bVOCs (Moore-Landecker and Stotzky, 1973;Chaurasia et al., 2005;Giorgio et al., 2015). In order to evaluate the effect of bVOCs on fungal cellular structures, light microscopy was performed on hyphae of Phoma sp., Colletotrichum sp., Coleophoma sp., and P. cinnamomi after exposure to C. vaccinii MWU328 bVOCs (Figure 3). We selected MWU328 for this analysis because it demonstrated antifungal activity against all fungi and oomycete tested, but not complete growth inhibition. ...
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... selected MWU328 for this analysis because it demonstrated antifungal activity against all fungi and oomycete tested, but not complete growth inhibition. In Coleophoma sp., hyphal cell membranes had pulled away from the cell wall, and there was a higher than normal proportion of empty cells in treated (Figures 3H,I) vs. control hyphae ( Figure 3G). There was abnormal swelling and deformation of hyphae in Phoma sp., Colletotrichum sp., and P. cinnamomi (Figures 3B,C,E,F,K,L), as well as an absence of sporangia in P. cinnamomi. ...
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... selected MWU328 for this analysis because it demonstrated antifungal activity against all fungi and oomycete tested, but not complete growth inhibition. In Coleophoma sp., hyphal cell membranes had pulled away from the cell wall, and there was a higher than normal proportion of empty cells in treated (Figures 3H,I) vs. control hyphae ( Figure 3G). There was abnormal swelling and deformation of hyphae in Phoma sp., Colletotrichum sp., and P. cinnamomi (Figures 3B,C,E,F,K,L), as well as an absence of sporangia in P. cinnamomi. ...
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... Coleophoma sp., hyphal cell membranes had pulled away from the cell wall, and there was a higher than normal proportion of empty cells in treated (Figures 3H,I) vs. control hyphae ( Figure 3G). There was abnormal swelling and deformation of hyphae in Phoma sp., Colletotrichum sp., and P. cinnamomi (Figures 3B,C,E,F,K,L), as well as an absence of sporangia in P. cinnamomi. ...
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... used principal components analysis (PCA) for an untargeted approach to evaluate the relationships between the VOCs produced by Phoma sp., C. vaccinii MWU328, and MWU328W in mono-and co-culture (Figure 5, Supplementary Figures 3, 4). Using the 53 microbial VOCs as the variables and the six biological replicates of each culture condition as the observations, the presence or absence of bVOCs vs. fVOCs explains the largest proportion of variance in the model (PC1, 21.2%). ...
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... of MWU328 and MWU328W cluster together along PC1 < 0, and away from the Phoma sp. monocultures clustered in PC1 > 0. Importantly, the co-cultures do not fall between the fungal and bacterial monoculture clusters, demonstrating that the VOCs of the co-culture are not a linear combination of fVOCs and bVOCs (Figure 5, Supplementary Figure 3). Further, the two cocultures do not cluster together as the two monocultures of bacteria do, showing that the volatile metabolomes created by co-culture differ based on the presence or absence of intact C. 2 | Volatile metabolites that are significantly more abundant than blank media as a function of sample type. ...
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... qualitative and quantitative data indicate that wild-type C. vaccinii MWU328 produces more VOCs at higher concentrations in monoculture than its QS mutant. Of the 45 VOCs detected in MWU328 or MWU328W in monoculture, 30 were detected in at least two-fold higher concentration in the wild type vs. the quorum-insensitive mutant (Figure 6, Supplementary Table 3). Of these, four compounds were significantly greater in wild type (p < 0.05), and compounds CA-18 and UNK-27 were not detectable in the QS mutant. ...
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... The sterilized A. auricula bag was inoculated with HW 15 strains and then cultured in the incubator (25 ℃, RH = 40%). Some of the bag was taken out when the A. auricula mycelium covered half of the bag, and the bottom end of the bag was punched to inoculate with activated A. flavus spores to continue the culture [29]. The growth of the mycelium on the bag was observed and recorded. ...
Auricularia auricula is one of the main edible fungi widely cultivated in China. Aspergillus flavus is the most common class of pathogenic bacteria fungi that produces the high toxicity of the aflatoxins, which is one of the fungal diseases of A. auricula. Morphological observation of A. flavus mycelium and A. auricula mycelium in plate confrontation, mutual inhibition of growth at different germination times, and the interaction of A. flavus liquid culture solution and A. flavus volatiles with A. auricula mycelium were used to investigate the mechanism of the interaction between A. flavus and A. auricula mycelium. Mycelium of A. auricula and A. flavus had a mutual inhibitory effect, but A. auricula mycelia had a stronger inhibitory effect on the growth of A. flavus mycelia. The results of the interaction between A. flavus volatiles and A. auricula volatiles were also the same and the inhibition of A. flavus by volatiles from A. auricula mycelium about 11%. After 240 h, the inhibition rate of A. flavus liquid culture solution on A. auricula mycelium reached up to about 20%. Some antimicrobial substances such as small peptides and organic acids produced in the metabolites of A. flavus liquid culture solution were the main reasons of the growth inhibition of A. auricula mycelium. The main inhibitory substances were 2-butanone, 2-butanone dimer, etc. Further study of AFT B1 and AFT B2 revealed that aflatoxins could migrate from the medium to the mycelia and the fruiting body of A. auricula, but the migration rate was basically lower than 10‱. The mycelia of A. auricula had a strong degradation of aflatoxins in the growth process. So, the mechanism of antifungal activity of these substances was studied to provide a theoretical basis for future chemical synthesis.
Graphical Abstract
... Detection of VOCs production was carried out with 7 endophytic Bacillus spp. using sandwich plate method [25]. Two base plates were used in this study for detection of VOCs against the plant pathogenic fungi (M. ...
Endophytic bacteria serve as a rich source of diverse antimicrobial compounds. Recently, there has been a growing interest in utilizing endophytic Bacillus spp. as biological agents against phytogenic fungi, owing to their potential to produce a wide range of antimicrobial substances. The objective of this research was to investigate the protective abilities of 15 endophytic Bacillus spp. isolated from previous study from wheat plant, against the phytopathogenic fungi, Fusarium graminearum and Macrophomina phaseolina. A dual culture plate assay was conducted as a preliminary analysis, revealing that 7 out of 15 endophytic Bacillus spp. demonstrated inhibition against one or both of the phytopathogenic fungi used in this study. All seven endophytes were further assessed for the presence of diffusible antifungal metabolites. The cultures were grown in potato dextrose broth for 120 h, and the cell-free supernatant was extracted and analyzed using the cup plate method. The methanolic extract yielded similar results to the dual culture plate analysis, except for WL2-15. Additionally, deformities in the mycelial structure were examined under the light microscope upon exposure to methanolic extract. Furthermore, the analysis and identification of metabolites were carried out via gas chromatography–mass spectrometry of methanolic extract from selected seven endophytic Bacillus spp. The chromatogram revealed the presence of some major peaks such as tridecanoic acid, methyl ester, hydroperoxide, 1-methylbutyl, 9-octadecenamide, (z)-, hexane-1,3,4-triol, 3,5-dimethyl- tetradecanoic acid. To the best of our knowledge, this is the first report of these biocontrol agents in endophytic Bacillus spp. Interestingly, volatile organic compound production was also seen in all the isolates against the phytopathogenic fungi.
... In addition, Trichoderma sp., Phoma sp., and Colletotrichum sp. Exposed to VOCs from Chromobacterium vaccinii show extensive morphological abnormalities, such as swollen hyphal cells, vacuolar deposits, and cell wall alterations [99]. This action corroborates our findings in the microscopy of fungi exposed to VOCs. ...
In response to the escalating demand for sustainable agricultural methodologies, the utilization of microbial volatile organic compounds (VOCs) as antagonists against phytopathogens has emerged as a viable eco-friendly alternative. Microbial volatiles exhibit rapid diffusion rates, facilitating prompt chemical interactions. Moreover, microorganisms possess the capacity to emit volatiles constitutively, as well as in response to biological interactions and environmental stimuli. In addition to volatile compounds, these bacteria demonstrate the ability to produce soluble metabolites with antifungal properties, such as APE Vf, pyoverdin, and fragin. In this study, we identified two Pseudomonas strains (BJa3 and MCal1) capable of inhibiting the in vitro mycelial growth of the phytopathogenic fungus Aspergillus flavus, which serves as the causal agent of diseases in sugarcane and maize. Utilizing GC/MS analysis, we detected 47 distinct VOCs which were produced by these bacterial strains. Notably, certain volatile compounds, including 1-heptoxydecane and tridecan-2-one, emerged as primary candidates for inhibiting fungal growth. These compounds belong to essential chemical classes previously documented for their antifungal activity, while others represent novel molecules. Furthermore, examination via confocal microscopy unveiled significant morphological alterations, particularly in the cell wall, of mycelia exposed to VOCs emitted by both Pseudomonas species. These findings underscore the potential of the identified BJa3 and MCal1 Pseudomonas strains as promising agents for fungal biocontrol in agricultural crops.
... PDA plates were incubated at room temperature and mycelial growth was measured daily for 7 days as described above. The percentage of disease inhibition was calculated as percent of inhibition (%) = [(GC-GT)/GC] × 100, where GC (growth control) represents the mean diameter of untreated spores grown in PDA and GT (growth treatment) represents the mean diameter of PAWtreated spores or direct plasma-treated spores or nystatin-treated spores grown in PDA 45,46 . ...
Ascosphaera apis is a worldwide pathogenic fungi of honeybees that can cause a decline in bee populations. In this study, we investigated the antifungal activity of non-thermal plasma on fungal growth. Spore inactivation after exposure to gas plasma by liquid phase and plasma activated water (PAW) and pathogenicity of A. apis in vivo were also examined. The results demonstrated that the mycelial growth of fungi was completely inhibited after argon plasma treatment. Both gas plasma and PAW exposures resulted in a significant decrease of A. apis spore numbers, maximum reduction of 1.71 and 3.18-fold, respectively. Germinated fungal spores on potato dextrose agar were also reduced after plasma treatment. SEM analysis revealed a disruption in the morphological structure of the fungal spores. The pathogenicity of A. apis on honeybee larvae was decreased after spores treated by gas plasma and PAW with a disease inhibition of 63.61 ± 7.28% and 58.27 ± 5.87%, respectively after 7 days of cultivation. Chalkbrood in honey bees have limited control options and our findings are encouraging. Here, we demonstrate a possible alternative control method using non-thermal plasma for chalkbrood disease in honeybees.
... The sterilized A. auricula bag was inoculated with HW 15 strains and then cultured in the incubator (25 ℃, RH = 40%). Some of the bag was taken out when the A. auricula mycelium covered half of the bag, and the bottom end of the bag was punched to inoculate with activated A. avus spores to continue the culture [17] . The growth of the mycelium on the bag was observed and recorded. ...
Auricularia auricula is one of the main edible fungi widely cultivated in China. Aspergillus flavus that is the most common class of pathogenic bacteria fungi produced the high toxicity of the aflatoxins, which is one of the fungal diseases of A. auricula. Morphological observation of A. flavus mycelium and A. auricula mycelium in plate confrontation, mutual inhibition of growth at different germination times, and the interaction of A. flavus liquid culture solution and A. flavus volatiles with A. auricula mycelium were used to investigate the mechanism of the interaction between A. flavus and A. auricula mycelium. Mycelium of A. auricula and A. flavus had a mutual inhibitory effect, but A. auricula mycelia had stronger inhibitory effect on the growth of A. flavus mycelia, besides that the results of the interaction between A. flavus volatiles and A. auricula volatiles were also the same and the inhibition of A. flavus by volatiles from A. auricula mycelium about 11%. After 240 h, the inhibition rate of A. flavus liquid culture solution on A. auricula mycelium reached up to about 20%. It was analyzed that some antimicrobial substances such as small peptides and organic acids produced in the metabolites of A. flavus liquid culture solution were the main reasons of the growth inhibition of A. auricula mycelium. The main inhibitory substances were 2-Butanone, 2-Butanone dimer, etc. Further study of AFT B 1 and AFT B 2 revealed that aflatoxins could migrate from the medium to the mycelia and the fruiting body of A. auricula , but the migration rate was basicly lower than 10‱. The mycelia of A. auricula had strong degradation of aflatoxins in the growth process. So the mechanism of antifungal activity of these substances was studied to provide a theoretical basis for future chemical synthesis.
... 60%), only about 36% of its VOCs were detected in lower amounts in dual-culture. Only three other studies have tackled the subject of volatile and/or non-volatile metabolomes in the context of VOCs-confronta tion between two microbial agents (63)(64)(65); all of them reported modulation of VOCs detection comparing dual and monocultures-but not necessarily down-regulation along with production of confrontation-induced specific VOCs. ...
... In the context of strong fungal growth inhibition by C. vaccinii bacterial VOCs against Phoma sp., another study reported a reduction, in dual-culture as compared to C. vaccinii monoculture, of DMTriS and 1-octanol, both identified as bacterial antifungal volatiles against Phoma sp. (65). Together with measurement of a total reduction of VOCs belonging to our Microbacterium strain, these results correlated positively the observation of VOCs depletion in dual-culture headspace with observation of VOCs antagonist bioactivity. ...
... We can conclude that those two VOCs act like signal molecules rather than being metabolic waste and their production to be activated by the interaction, maybe as a response to bacterial antifungal VOCs. These results are consistent with a previous study showing some VOCs are co-culture induced (65), proving the importance of feedback loops between fungal VOCs and bacterial VOCs resulting in the production of volatiles with potentially new properties. ...
Volatile organic compounds (VOCs) produced by plant-associated microorganisms could serve as natural biocontrol compounds. In this work, we investigate the potential of wheat rhizosphere Microbacterium and Arthrobacter actinomycetes to inhibit the growth of major wheat phytopathogenic fungi, Fusarium graminearum and Zymoseptoria tritici via production of antifungal VOCs. A correlative analysis between fungal-growth inhibition versus bacterial volatilomic profiles identified four dimethylpolysulfide (DMPS) VOCs as the main active compounds behind their biocontrol potential. Subsequent inhibition assays reveal that DMTriS (dimethyltrisulfide) exhibits the strongest inhibition effects, then dimethyldisulfide (DMDiS). Further investigation focuses on the mechanisms behind F. graminearum -growth inhibition by the most active strain Microbacterium JM188 in dual culture. Surprisingly, nine interaction-induced VOCs, including two fungal sesquiterpenes, were exclusively detected in dual cultures, suggesting a complex interplay between microbial VOC production and sensing. More importantly, all JM188 VOCs, including antifungal DMPS, were less abundant in dual cultures, suggesting an uptake of bacterial VOCs by the fungus. Quantification of pure DMPS after confrontation with F. graminearum confirmed complete and partial uptake by the fungus of DMTriS and DMDiS VOCs, respectively, suggesting a potential link between the fungal uptake level of bacterial VOCs and their toxicity. Finally, we demonstrated that F. graminearum growth inhibition leads to a complete depletion of DON (deoxynivalenol) carcinogenic mycotoxins, highlighting a significant modulation of fungal metabolism. Collectively, these results pinpoint DMPS as broad-range fungal-inhibiting VOCs produced by rhizosphere Microbacterium and Arthrobacter , and emphasize the extensive VOC-mediated interplay between bacterial biocontrol agents and fungal pathogens.
IMPORTANCE
As the management of wheat fungal diseases becomes increasingly challenging, the use of bacterial agents with biocontrol potential against the two major wheat phytopathogens, Fusarium graminearum and Zymoseptoria tritici , may prove to be an interesting alternative to conventional pest management. Here, we have shown that dimethylpolysulfide volatiles are ubiquitously and predominantly produced by wheat-associated Microbacterium and Arthrobacter actinomycetes, displaying antifungal activity against both pathogens. By limiting pathogen growth and DON virulence factor production, the use of such DMPS-producing strains as soil biocontrol inoculants could limit the supply of pathogen inocula in soil and plant residues, providing an attractive alternative to dimethyldisulfide fumigant, which has many non-targeted toxicities. Notably, this study demonstrates the importance of bacterial volatile organic compound uptake by inhibited F. graminearum , providing new insights for the study of volatiles-mediated toxicity mechanisms within bacteria-fungus signaling crosstalk.
... The control group was cultured under the same conditions but without P. ureafaciens. Fungal diameter was measured using ImageJ and quantified as percentage growth inhibition, according to the formula described by Ebadzadsahrai et al. (127). ...
Increasing evidence suggests that in disease-suppressive soils, microbial volatile compounds (mVCs) released from bacteria may inhibit the growth of plant-pathogenic fungi. However, the antifungal activities and molecular responses of fungi to different mVCs remain largely undescribed. In this study, we first evaluated the responses of pathogenic fungi to treatment with mVCs from Paenarthrobacter ureafaciens . Then, we utilized the well-characterized fungal model organism Saccharomyces cerevisiae to study the potential mechanistic effects of the mVCs. Our data showed that exposure to P. ureafaciens mVCs leads to reduced growth of several pathogenic fungi, and in yeast cells, mVC exposure prompts the accumulation of reactive oxygen species. Further experiments with S. cerevisiae deletion mutants indicated that Slt2/Mpk1 and Hog1 MAPKs play major roles in the yeast response to P. ureafaciens mVCs. Transcriptomic analysis revealed that exposure to mVCs was associated with 1,030 differentially expressed genes (DEGs) in yeast. According to gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses, many of these DEGs are involved in mitochondrial dysfunction, cell integrity, mitophagy, cellular metabolism, and iron uptake. Genes encoding antimicrobial proteins were also significantly altered in the yeast after exposure to mVCs. These findings suggest that oxidative damage and mitochondrial dysfunction are major contributors to the fungal toxicity of mVCs. Furthermore, our data showed that cell wall, antioxidant, and antimicrobial defenses are induced in yeast exposed to mVCs. Thus, our findings expand upon previous research by delineating the transcriptional responses of the fungal model.
IMPORTANCE
Since the use of bacteria-emitted volatile compounds in phytopathogen control is of considerable interest, it is important to understand the molecular mechanisms by which fungi may adapt to microbial volatile compounds (mVCs). Paenarthrobacter ureafaciens is an isolated bacterium from disease-suppressive soil that belongs to the Actinomycetota phylum. P. ureafaciens mVCs showed a potent antifungal effect on phytopathogens, which may contribute to disease suppression in soil. However, our knowledge about the antifungal mechanism of mVCs is limited. This study has proven that mVCs are toxic to fungi due to oxidative stress and mitochondrial dysfunction. To deal with mVC toxicity, antioxidants and physical defenses are required. Furthermore, iron uptake and CAP proteins are required for antimicrobial defense, which is necessary for fungi to deal with the thread from mVCs. This study provides essential foundational knowledge regarding the molecular responses of fungi to inhibitory mVCs.
... Where Absneg and Abstreatment are the absorbances of the negative control and treatment at 600 nm, respectively (Ebadzadsahrai et al., 2020). ...
In this study, the application of ionic materials as a combination antibiotic drug was investigated. The fluoroquinolone, Norfloxacin, was converted into the ionic form and combined with the cationic dye, IR780+, using an ion-exchange reaction. The resulting ionic combination drug possesses two killing mechanisms in one compound. The antibiotic chemical mechanism along with the photothermal mechanism that was acquired by adding IR780 to the compound led to the development of a combination antibiotic drug. This ionic combination drug consisting of Norfloxacin anion and IR780 cation is easily dispersed in water using sonication waves. The parent compounds and ionic combination drug, dissolved in organic solvent and dispersed in water, were characterized, and the photophysical properties were studied in detail. It was discovered that the aqueous ionic combination drugs exhibited significant changes in absorbance and photoluminescent properties. In aqueous media, the dispersed ionic combination drug exhibited a very broad absorbance with an additional peak around 1000 nm which is advantageous in photothermal. A significant decrease in the quantum yield along with enhanced non-radiative rate constant was observed for the combination drug in the aqueous. The photothermal mechanism is present in both the parent IR780 dye and the ionic combination drug. The ionic combination drug displayed a high light-to-heat conversion efficiency and temperature increase similar to the parent dye. The combination of both killing mechanisms in the ionic combination drug resulted in enhanced antibacterial activity against Escherichia coli as compared to the parent Norfloxacin and IR780-I individually.
... Chromobacterium have been a rich source of bioactive molecules [17][18][19] . Recently, they have been used and developed as biocontrol agents to control insect pests 20,21 and to control plant pathogens [22][23][24][25] . ...
... A survey of literature identified a few examples of strains of Chromobacterium being evaluated as potential biocontrol agents to control plant pathogens [22][23][24][25] . Two of the studies use Chromobacterium haemolyticum C-61, which displayed strong antifungal activities against several plant pathogens 23,24 . ...
... Han et al. identified Chromobacterium sp. JH7 during a screening assay to identify antagonists of Cylindrocarpon destructans, a root rot pathogen of ginseng [22][23][24][25] . The authors were not able to identify the strain to the species level. ...
The compound 2,4-diacetylphloroglucinol (DAPG) is a broad-spectrum antibiotic that is primarily produced by Pseudomonas spp. DAPG plays an important role in the biocontrol disease suppressing activity of Pseudomonas spp. In the current study, we report the discovery of the DAPG biosynthetic cluster in strains of Chromobacterium vaccinii isolated from Brazilian aquatic environments and the distribution of the biosynthetic cluster in the Chromobacterium genus. Phylogenetic analysis of the phlD protein suggests the biosynthetic cluster probably entered the genus of Chromobacterium after a horizontal gene transfer event with a member of the Pseudomonas fluorescens group. We were able to detect trace amounts of DAPG in wild type cultures and confirm the function of the cluster with heterologous expression in Escherichia coli. In addition, we identified and verified the presence of other secondary metabolites in these strains. We also confirmed the ability of C. vaccinii strains to produce bioactive pigment violacein and bioactive cyclic depsipeptide FR900359. Both compounds have been reported to have antimicrobial and insecticidal activities. These compounds suggest strains of C. vaccinii should be further explored for their potential as biocontrol agents.
... VOCs have long been recognized to confer information about biological processes in health and disease 1,2,3 , yet reliable methods for the study of these molecules in vitro have lagged behind. Works overcoming the challenges associated with in vitro sampling methodology have provided evidence for the extensive roles of volatile metabolites in biology, including but not limited to, serving as putative disease biomarkers 4,5,6 , extracellular signaling molecules in archaea, fungi, bacteria, protists, plants, and animals 7-16 , and drivers of inter-and intra-kingdom phenotype and function 7,9,10,11,17,18,19,20 . Despite the insights gained, nearly all approaches suffer from one or more of the following major limitations: i) detection of exogenous VOCs from plastics or the sampling environment 18,21,22 , ii) low analyte sensitivity and poor signal-to-noise relative to VOCs originating from nonendogenous sources, as a consequence of indirect 18,23 and passive (equilibrium-based) sampling techniques 21,24,25 and/or iii) disrupt culture viability 26,27,28 , limiting interpretation in response to environmental stimuli or perturbation. ...
Volatile organic compounds (VOCs) are a biologically important subset of an organism's metabolome, yet in vitro techniques for the analysis of these small molecules vary substantially in practice, restricting the interpretation and reproducibility of study findings. Here, we present an engineered culture tool, termed the Biodome, designed to enhance analyte sensitivity by integrating dynamic headspace sampling methodology for the recovery of VOCs from viable biological cultures. We validate the functionality of the device for in vitro volatile metabolomics utilizing computational modeling and fluorescent imaging of mammalian cell culture. We then leverage comprehensive two-dimensional gas chromatography coupled with a time-of-flight mass spectrometer and the enhanced sampling capabilities afforded by our tool to identify seven VOCs not found in the media or exogenously derived from the sampling method (typical pitfalls with in vitro volatilome analysis). We further work to validate the endogenous production of these VOCs using two independent approaches: (i) glycolysis-mediated stable isotopic labeling techniques using 13C6-D-glucose and (ii) RNA interference (RNAi) to selectively knockdown beta-oxidation via silencing of CPT2. Isotope labeling reveals 2-Decen-1-ol as endogenously derived with glucose as a carbon source and, through RNAi, we find evidence supporting endogenous production of 2-ethyl-1-hexene, dodecyl acrylate, tridecanoic acid methyl ester and a low abundance alkene (C17) with molecular backbones likely derived from fatty acid degradation. To demonstrate applicability beyond mammalian cell culture, we assess the production of VOCs throughout the log and stationary phases of growth in ampicillin-resistant DH5alpha Escherichia coli. We identified nine compounds with results supporting endogenous production, six of which were not previously associated with E. coli. Our findings emphasize the improved capabilities of the Biodome for in vitro volatile metabolomics and provide a platform for the standardization of methodology.
