Volatile compounds from Gluconacetobacter diazotrophicus PAL5 regulate photosynthesis and protein networks to promote Arabidopsis thaliana growth.

The chemical diversity of volatile organic compound (VOC) emissions from terrestrial vegetation is relatively well understood, while research on VOC emissions from freshwater and marine systems has largely focused on dimethyl sulfide (DMS) and isoprene. Through VOC concentration measurements in water samples, and VOC flux measurements using floating chambers and the direct eddy covariance (EC) technique we aim to evaluate aquatic ecosystems as sources of VOCs. Here, we present selected case studies that demonstrate the need to consider other VOCs beyond DMS and isoprene when assessing aquatic sources of atmospheric VOCs.A survey of depth-specific VOC concentrations in water from four Alpine lakes in France showed that VOC concentrations were highest either at the deep chlorophyll maximum or at the surface. The VOC composition profiles differed between depths and lakes. In another study, we assessed net emissions of VOCs from three ponds in a rewetted peatland forest in Denmark. Again, the three ponds showed differences in the quantity and diversity of their emission profiles. Over 100 chemical species were detected, including acetone, acetaldehyde, isoprene, other terpenoids, and hydrocarbons. The most eutrophic and acidic pond had highest emission rates but lower VOC diversity compared to the alkaline ponds.The VOC emission rates and compositions also vary over time, depending on the balance between VOC production, consumption, and emission rates, driven by both biotic and abiotic factors. Our EC flux measurements on Utö Island in the Baltic Sea show strong seasonal variation in marine VOC emissions, which can be coupled to the biomass and phenology of the phytoplankton as well as to environmental factors.We highlight the emerging diversity of VOC emissions from aquatic ecosystems. These emissions need to be better quantified to assess their atmospheric fate and implications.

Cancer diagnosis by breath analysis: what is the future?

Tailpipe volatile organic compounds (VOCs) emissions from Chinese gasoline vehicles under different vehicle standards, fuel types, and driving conditions

Volatile compounds and extrafloral nectar are common defenses of wild plants; however, in crops they bear an as-yet underused potential for biological control of pests and diseases. Odor emission and nectar secretion are multigene traits in wild plants, and thus form difficult targets for breeding. Furthermore, domestication has changed the capacity of crops to express these traits. We propose that breeding crops for an enhanced capacity for tritrophic interactions and volatile-mediated direct resistance to herbivores and pathogens can contribute to environmentally-friendly and sustainable agriculture. Natural plant volatiles with antifungal or repellent properties can serve as direct resistance agents. In addition, volatiles mediating tritrophic interactions can be combined with nectar-based food rewards for carnivores to boost indirect plant defense.

The presence of knots or heartwood influences the amount and composition of volatile organic compound (VOC) emissions associated with drying of southern pine lumber. Experimental kiln charges of lumber containing 0 to 5% of knot volume gave VOC emissions ranging from 2.86 to 4.25 lb of carbon/dry ton of wood. Studies of emissions from sapwood and knots showed that knots contain about ten times the amount of volatile terpenes found in sapwood. Consequently half of the total volatile emissions would come from 5% of knot volume in sapwood. However, correlation coefficients of knot frequency or volume with VOC emissions obtained from experimental kiln studies were only 0.57 and 0.51, respectively. Southern pine heartwood contains about five times the amount of volatile terpenes found in sapwood and more of the volatile compounds present in heartwood are emitted than from knots. Therefore, small variations in the amount of heartwood result in large changes in VOC emissions in drying southern pine lumber.

Composition and emission of VOC from biogas produced by illegally managed waste landfills in Giugliano (Campania, Italy) and potential impact on the local population

The fruit of chili pepper (Capsicum spp.) is used fresh or dried all over the world because of their unique pungency, color, taste, and aroma. Limited information is available about a hypothetical correlation between volatile organic compound (VOC) emission and spiciness of different pepper species and varieties. The aromatic profile and the pungency of 21 different Capsicum varieties, belonging to four different Capsicum species, have been investigated to evaluate a possible correlation between different VOC emission and their spiciness. The measurement of capsaicinoid concentration was performed by a high-performance liquid chromatography method while the VOCs from fresh samples were extracted using a proton-transfer-reaction time-of-flight mass spectrometer. The partial least squares regression model used for the determination of capsaicin content from VOCs reported high performances (r = 0.84 in the test set). VOCs detected at m/z 103.075 and m/z 43.054 showed a higher contribution in the correlation with the capsaicin content. This study has provided clear and promising results, showing a real possibility to use these tools in routine operations for predicting the spiciness of fresh peppers useful for breeding programs and consumers.

Volatile organic compounds (VOCs)are important air pollutants in China, and control of their emission is an important subject of air pollution prevention and control.Architectural coatings play a significant role as sources of atmospheric VOCs in China.Due to recent economic development and increase in the levels of urbanization, the building of residences and other buildings is ongoing all the time, which results in increasing demand for architectural coatings and the VOCs pollution caused by painting operations.However, there are few studies of the VOCs emission factors and VOCs emissions due to architectural coatings.In this paper, a set of bottom-up VOCs emission inventory estimation methods for architectural coatings in China was established.The architectural coatings VOCs emission factors were gotten by actual measurement of VOCs in architectural coatings and by summarizing studies of VOCs contents in architectural coatings.Combining these results with the consumption of architectural coating sources, a VOCs emission inventory of architectural coatings in China from 2013 to 2016 was established.The results showed the following.① VOCs emission factors were 24.63 g·kg-1 for water-based interior wall coatings; 17.5 g·kg-1 and 298.8 g·kg-1 for water-based and solvent-based exterior wall coatings, respectively. They were 2.75, 87.86, and 400 g·kg-1 for water-based, reaction-type, and solvent-based waterproof coatings, respectively. For water-based, solventless, and solvent-based floor coatings, they were 86.2, 25.24, and 317 g·kg-1, respectively; and 31.95 g·kg-1 and 464.61 g·kg-1 for water-based and solvent-based anticorrosive coatings respectively. The emission factors were 59.7 g·kg-1 and 347.2 g·kg-1 for water-based and solvent-based fire retardant coatings, respectively. ② VOCs emissions from the use of architectural coatings were 255900 t, 287500 t, 319700 t, and 348000 t from 2013 to 2016 in China, with an upward trend. ③ Total VOCs emissions from architectural coatings was 348000 t in 2016, and the VOCs emissions from floor coatings was 78700 t, accounting for 22.61% with the maximum contribution rate. The VOCs emissions from exterior wall coatings were 64900 t, accounting for 18.65% (second place), and the VOCs emissions from fire retardant coatings and anticorrosive coatings (functional coatings) were 64500 t and 50800 t, accounting for 18.53% and 14.6% respectively. The VOCs emissions from waterproof coatings and interior wall coatings were 46100 t and 43000 t, accounting for 13.25% and 12.36%, respectively. ④ The consumption of water-based architectural coatings reached a total of 4889400 t in 2016 with VOCs emissions of 97900 t and average VOCs emissions factor of 20.02 g·kg-1; however, the consumption of solvent-based architectural coatings totaled 636500 t with VOCs emissions of 227200 t and average VOCs emission factor of 356.95 g·kg-1. Reducing the consumption of solvent-based coatings would be favorable for reduction of VOCs emissions. ⑤ As for the spatial distribution, architectural coating-related VOCs emissions were mainly concentrated in Shandong, Jiangsu, Zhejiang, Henan, Sichuan, Guangdong, and Hebei provinces, which have large populations. The province with the highest VOCs emissions was Shandong, with a percentage of 9.36%, and the second was Jiangsu, with a percentage of 8.54%.

BACKGROUNDThe emission of volatile organic compounds (VOC) during the composting process is mainly responsible for the odors generated in these types of waste treatment plants. In this work, VOC emissions from the source‐separated organic fraction of municipal solid waste (OFMSW) composting process have been investigated in 50 L pilot reactors operating under different aeration control strategies during the active decomposition stage.RESULTSThe VOC emissions from traditional aeration control options such as oxygen feedback control or cyclic on‐off aeration have been compared with VOC emissions under an oxygen uptake rate (OUR) control strategy. Total VOC emission (mg C m‐3) and VOC composition (%) have been determined during the first active decomposition stage of composting. Study of VOC composition indicated a high presence of terpenes. Carcinogenic compounds, such as furans, have occasionally been found at very low concentration. Results indicate some differences in VOC composition according to the aeration strategy used.CONCLUSIONThe evolution of total VOC emissions was relatively similar, being high in the first days of the process. However, the results obtained show some differences in VOC composition depending on the aeration strategy used. The OUR controller provided a more steady emissions profile, which will help the performance of further gas treatment operations, specially biological systems. © 2013 Society of Chemical Industry

Based on the demand for volatile organic compounds (VOCs) emissions controlled in Tianjin, VOC emissions compositions from four typical solvent use industries (automobile painting, furniture painting, wood-based panel manufacturing, Packaging & Printing) were measured by field sampling and analysis, the influence of different treatment facilities on VOCs composition and the ozone formation potentials (OFP) of species were analysed. The results showed that the major VOCs emissions species were aromatics and oxygenated VOCs. Among all waste gas treatment facilities, the catalytic combustion system could reshape the VOCs profile from different industries, and which made the proportion of ethylene increased from 5.81% to 28.30%. Aromatics had a great influence on OFP. The VOCs species with the largest OFP contribution was m/p-xylene, which contributed 16.36% of the total OFP.

Serendipita indica is a plant growth-promoting fungus. It is a natural soil dweller that can colonize the roots of a wide range of plants, including cultivated crops. S. indica has been reported to improve plant nutrient uptake and increase stress tolerance when inoculated into the soil. The present study was undertaken to study the effect of volatile organic compounds (VOCs) of S. indica on salt-stressed Ocimum basilicum ‘Fin vert’ in vitro, either in a culture vessel with a semi-solid medium or via a modified temporary immersion bioreactor system (SETIS). For all salt concentrations, VOCs of S. indica significantly improved plant growth in both semi-solid medium and SETIS bioreactors. This resulted in heavier and taller plants, more shoots per plant, and longer roots. This was even observed for the control without salt. At 9 g/L NaCl, plants with Serendipita were able to give longer roots than those without (1.2 cm vs. 0.0 and 1.7 cm vs. 1.7 cm) in the semi-solid medium and SETIS, respectively. Nevertheless, the VOCs were not able to make the plant salt tolerant to this high concentration. The increase in total phenolic and flavonoid content and radical scavenging suggest that the antioxidant defense system is triggered by the S. indica VOCs. In the semi-solid system, without VOCs, 1 g/L NaCl led to an increase in total chlorophyll content (TCC) and a significant decrease in TCC was further measured only at 6 g/L NaCl or more. However, when VOCs were added, the bleaching effect of the salt was partially restored, even at 6 and 9 g/L NaCl. A significant decrease in TCC was also measured in the SETIS system at 6 g/L NaCl or more and treatment with VOC did not make any difference. An exception was 9 g/L, where the VOC-treated plants produced more than three times more chlorophyll than the non-treated plants. These findings will encourage the application of Serendipita indica for stress reduction. In addition, the proposed original adaptation of a temporary immersion system will be instrumental to investigate stress reduction associated with volatile compounds and better understand their mechanism of action.

BackgroundGray mold, attributed to Botrytis cinerea, poses a substantial threat to food security in fruit-growing regions impacted by global climate change. Addressing this disease requires the utilization of either resilient plant varieties or advanced technological interventions. In this study, the research focused on examining the volatile organic compounds (VOCs) emitted by synthetic essential oils, namely thymol, eugenol, 1,8-cineol, and their combination, as potential biological fumigants against B. cinerea on Golden Delicious apples.ResultsIn this study, a total of 53 compounds were identified and categorized into six distinct classes, which included (1) terpenes, (2) esters, (3) C6 compounds, (4) alcohols, (5) acids, and (6) aldehydes. The results we obtained revealed significant variations in the volatile compounds present in apples after harvest when treated with different essential oils to combat B. cinerea. Among the VOCs found in the fruits, the most abundant ones were pentanal, nerol, and ethyl octanoate. The essential oil combination of thymol, eugenol, and 1,8-cineol (Thy + Eug + Fun) had the most significant impact on the volatile compound content in the fruits. Conversely, both B. cinerea and the essential oils were observed to increase the volatile organic compound content in the fruits after harvest.ConclusionThe findings from this study underscore the significance of essential oils as effective biological fumigants for countering Botrytis cinerea on apples. Furthermore, the study suggests that these essential oils have the potential to influence the composition of volatile organic compounds in postharvest apples. This research offers valuable insights into the intricate interplay between volatile organic compounds and essential oils in apples, emphasizing the critical role of essential oils in preserving fruit quality during the post-harvest period.Graphical abstract

Metabolic characterization of human adipose tissue-derived mesenchymal stromal/stem cells (ASCs) is of importance in stem cell research. The monitoring of the cell status often requires cell destruction. An analysis of volatile organic compounds (VOCs) in the headspace above cell cultures might be a noninvasive and nondestructive alternative to in vitro analysis. Furthermore, VOC analyses permit new insight into cellular metabolism due to their view on volatile compounds. Therefore, the aim of our study was to compare VOC profiles in the headspace above nondifferentiating and adipogenically differentiating ASCs. To this end, ASCs were cultivated under nondifferentiating and adipogenically differentiating conditions for up to 21 days. At different time points the headspace samples were preconcentrated by needle trap micro extraction and analyzed by gas chromatography/mass spectrometry. Adipogenic differentiation was assessed at equivalent time points. Altogether the emissions of 11 VOCs showed relevant changes and were analyzed in more detail. A few of these VOCs, among them acetaldehyde, were significantly different in the headspace of adipogenically differentiating ASCs and appeared to be linked to metabolic processes. Furthermore, our data indicate that VOC headspace analysis might be a suitable, noninvasive tool for the metabolic monitoring of (mesenchymal stem) cells in vitro.

Volatile organic compound emissions from an engine fueled with an ethanol-biodiesel-diesel blend

Characteristics of volatile organic compounds emission profiles from hot road bitumens