scholarly journals High-Throughput Volatilome Fingerprint Using PTR–ToF–MS Shows Species-Specific Patterns in Mortierella and Closely Related Genera

2021 ◽  
Vol 7 (1) ◽  
pp. 66
Author(s):  
Anusha Telagathoti ◽  
Maraike Probst ◽  
Iuliia Khomenko ◽  
Franco Biasioli ◽  
Ursula Peintner

In ecology, Volatile Organic Compounds (VOCs) have a high bioactive and signaling potential. VOCs are not only metabolic products, but are also relevant in microbial cross talk and plant interaction. Here, we report the first large-scale VOC study of 13 different species of Mortierella sensu lato (s.l.) isolated from a range of different alpine environments. Proton Transfer Reaction–Time-of-Flight Mass Spectrometry (PTR–ToF–MS) was applied for a rapid, high-throughput and non-invasive VOC fingerprinting of 72 Mortierella s.l. isolates growing under standardized conditions. Overall, we detected 139 mass peaks in the headspaces of all 13 Mortierella s.l. species studied here. Thus, Mortierellas.l. species generally produce a high number of different VOCs. Mortierella species could clearly be discriminated based on their volatilomes, even if only high-concentration mass peaks were considered. The volatilomes were partially phylogenetically conserved. There were no VOCs produced by only one species, but the relative concentrations of VOCs differed between species. From a univariate perspective, we detected mass peaks with distinctively high concentrations in single species. Here, we provide initial evidence that VOCs may provide a competitive advantage and modulate Mortierella s.l. species distribution on a global scale.

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1738 ◽  
Author(s):  
Giovanni Bittante ◽  
Qianlin Ni ◽  
Iuliia Khomenko ◽  
Luigi Gallo ◽  
Franco Biasioli

Volatile organic compounds (VOCs) are important contributors to meat aroma and are variably correlated with each other. To study the sources of variation and the correlations among meat VOCs, meat cuts from five animal species/categories (chicken, turkey, pork, veal, and beef; two animals/species/retailer: 100 meat cuts) were obtained by 10 retailers. Each cut was processed into four burgers, two of which were grilled and two were cooked in a water bath (400 meat burgers). VOCs were detected by Proton-Transfer-Reaction Time-of-Flight Mass-Spectrometry (PTR-ToF-MS). From these, 129 peaks were selected, of which 72 were tentatively identified as relevant VOCs. Pearson correlations revealed a large number of positive and negative relationships among the VOCs. A multivariate statistical analysis revealed that 87% of the matrix covariance was explained by 17 independent Latent Explanatory Factors (LEFs), which have been described and characterized. LEFs identified may be valuable tools for reducing the dimensionality of results from VOC analyses and can be useful for better understanding and interpreting the variation in the meat aroma profile, although further study is required to characterize their sensory meaning.


2020 ◽  
Vol 412 (26) ◽  
pp. 7131-7140
Author(s):  
Giovanni Pugliese ◽  
Felix Piel ◽  
Phillip Trefz ◽  
Philipp Sulzer ◽  
Jochen K. Schubert ◽  
...  

Abstract Proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) is a powerful tool for real-time monitoring of trace concentrations of volatile organic compounds (VOCs). The sensitivity of PTR-ToF-MS also depends on the ability to effectively focus and transmit ions from the relatively high-pressure drift tube (DT) to the low-pressure mass analyzer. In the present study, a modular ion-funnel (IF) is placed adjacent to the DT of a PTR-ToF-MS instrument to improve the ion-focusing. IF consists of a series of electrodes with gradually decreasing orifice diameters. Radio frequency (RF) voltage and direct current (DC) electric field are then applied to the electrodes to get the ions focused. We investigated the effect of the RF voltage and DC field on the sensitivity of a pattern of VOCs including hydrocarbons, alcohols, aldehydes, ketones, and aromatic compounds. In a proof-of-concept study, the instrument operating both as normal DT (DC-mode) and at optimal IF conditions (RF-mode) was applied for the breath analysis of 21 healthy human subjects. For the range of investigated VOCs, an improvement of one order of magnitude in sensitivity was observed in RF-mode compared with DC-mode. Limits of detection could be improved by a factor of 2–4 in RF-mode compared with DC-mode. Operating the instrument in RF-mode allowed the detection of more compounds in the exhaled air compared with DC-mode. Incorporation of the IF considerably improved the performance of PTR-ToF-MS allowing the real-time monitoring of a larger number of potential breath biomarkers.


2015 ◽  
Vol 8 (12) ◽  
pp. 13157-13197
Author(s):  
V. Perraud ◽  
S. Meinardi ◽  
D. R. Blake ◽  
B. J. Finlayson-Pitts

Abstract. Organosulfur compounds (OSC) are naturally emitted via various processes involving phytoplankton and algae in marine regions, from animal metabolism and from biomass decomposition inland. These compounds are malodorant and reactive. Their oxidation to methanesulfonic and sulfuric acids leads to the formation and growth of atmospheric particles, which are known to have negative effects on visibility, climate and human health. In order to predict particle formation events, accurate measurements of the OSC precursors are essential. Here, two different approaches, proton-transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) and canister sampling coupled with GC-FID are compared for both laboratory standards [dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS) and methanethiol (MTO)] and for a complex sample. Results show that both techniques produce accurate quantification of DMS. While PTR-ToF-MS provides real-time measurements of all four OSCs individually, significant fragmentation of DMDS and DMTS occurs, which can complicate their identification in complex mixtures. Canister sampling coupled with GC-FID provides excellent sensitivity for DMS, DMDS and DMTS. However, MTO was observed to react on metal surfaces to produce DMDS and, in the presence of hydrogen sulfide, even DMTS. Avoiding metal in sampling systems seems to be necessary for measuring all but dimethyl sulfide in air.


Author(s):  
Zhining Zhang ◽  
Hanyang Man ◽  
Fengkui Duan ◽  
Zhaofeng lv ◽  
Songxin Zheng ◽  
...  

Abstract A second wave of coronavirus disease 2019 (COVID-19) infections have emerged in summer Beijing, 2020, which provided an opportunity to explore the response of air pollution to reduced human activity. Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) coupled with Positive Matrix Factorization (PMF) source apportionment were applied to evaluate the pollution pattern and capture the detailed dynamic emission characteristics of volatile organic compounds (VOCs) during the representative period with the occurrence of O3 pollution episodes and the Beijing resurgence of COVID-19. The level of anthropogenic VOC was lower than the same period of previous years due to the pandemic and emission reduction measures. More than two-thirds of the observation period were identified as high-O3 days and VOCs exhibited higher mixing ratios and faster consumption rates in the daytime under high-O3 days. The identified VOC emission sources and the corresponding contributions during the whole observation period included: vehicle + fuel (12.41 ± 9.43%), industrial process (9.40 ± 8.65%), solvent usage (19.58 ± 13.46%), biogenic (6.03 ± 5.40%), background + long-lived (5.62 ± 11.37%), and two groups of oxygenated VOC (OVOC) factors (primary emission and secondary formation, 26.14 ± 15.20% and 20.84 ± 14.0%, respectively). Refined dynamic source apportionment results show that the “stay at home” tendency led to decreased emission (- 34.47 ± 1.90 %) and weakened morning peak of vehicle + fuel during the Beijing resurgence. However, growing emission of primary OVOCs (+ 51.10 ± 8.28%) with similar diurnal variation was observed in the new outbreak and afterwards, which might be related to the enhanced usage of pandemic products. The present study illustrated that more stringent VOC reduction measures towards pandemic products should be carried out to achieve the balanced emission abatement of NOx and VOC when adhering to regular epidemic prevention and control measures.


2019 ◽  
Vol 31 (4) ◽  
pp. 629-633
Author(s):  
Sergio Migliore ◽  
Maurizio Bivona ◽  
Enrico Gagliostro ◽  
Onofrio Buttitta ◽  
Francesca Lo Mascolo ◽  
...  

Scrapie resistance or susceptibility in sheep is associated with single nucleotide polymorphisms (SNPs) at codons 136, 154, and 171 of the prion protein gene ( PRNP). In addition, phenylalanine mutation at codon 141 has been recognized as a risk factor for atypical scrapie. In contrast, K222, D146, and S146 alleles confer genetic resistance to classical scrapie in goats. High-throughput genotyping technologies would provide significant benefits in scrapie eradication plans. The ability to resolve oligonucleotides varying in mass by less than a single nucleotide makes MALDI-TOF mass spectrometry (MS) a suitable platform for PRNP genotyping. We evaluated the commercial Myriapod scrapie kit (Diatech Pharmacogenetics), associated with a highly automated processing platform incorporating MALDI-TOF MS technology, to detect SNPs at codons 136, 154, 171, 141, and 222 of small ruminant PRNP. The Myriapod scrapie kit was accredited according to UNI CEI EN ISO/IEC 17025. We present the genotyping results of 10,960 sheep in Sicily and 1,822 goats in Sicily and Calabria (southern Italy) tested during 2017. We found a high frequency (43.9%) of the protective ARR allele in sheep and a promising 12.3% of the resistant K222 variant in goats. This efficient and high-throughput method is suitable for extensive PRNP genotyping, as requested in the European scrapie eradication plan.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1277 ◽  
Author(s):  
Carolina Muñoz-González ◽  
Francis Canon ◽  
Gilles Feron ◽  
Elisabeth Guichard ◽  
Maria Pozo-Bayón

To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for the compound ethyl decanoate that was significantly higher released in the presence of tannins. Strong interindividual differences on aroma persistence were also found. Significant positive correlations with the salivary total protein content and negative with the salivary flow were observed for specific compounds. This work has studied for the first time in vivo wine aroma persistence in real time from an analytical perspective.


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