Metabolite profiling of Clostridium difficile ribotypes using small molecular weight volatile organic compounds

Metabolomics ◽  
2014 ◽  
Vol 11 (2) ◽  
pp. 251-260 ◽  
Author(s):  
S. Kuppusami ◽  
M. R. J. Clokie ◽  
T. Panayi ◽  
A. M. Ellis ◽  
P. S. Monks
Insects ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 683
Author(s):  
Eric W. Riddick

Introduction: Evidence that volatile organic compounds (VOCs) and non-VOCs stimulate oviposition by aphidophagous predators is scattered throughout the literature. The objectives of this review are to (1) compile records indicating that VOCs and non-VOCs are responsible for oviposition stimulation, (2) calculate an egg production ratio (EPR) for stimulated predators, and (3) determine if EPR is correlated with vapor pressure and molecular weight of active compounds. Methods: The USDA (United States Department of Agriculture), National Agricultural Library, online digital catalog system was used to retrieve abstracts, then the full text of manuscripts on oviposition stimulants for predators. Oviposition-stimulating VOCs and non-VOCS were tabulated with molecular weights and vapor pressure estimates. EPRs were calculated for stimulated coccinellids, syrphids, and chrysopids. Results: Both VOCs and non-VOCs stimulated oviposition behavior by coccinellids and syrphids, but not chrysopids. EPR was greatest for syrphids. Two VOCs, (E)-β-farnesene and 3-methyl-2-butenal, stimulated very high EPR values by the syrphid Episyrphusbalteatus. Regardless of predator taxa, EPR was negatively and positively correlated with molecular weight and vapor pressure, respectively. Conclusions: Syrphids (rather than coccinellids or chrysopids) produce more eggs in response to VOCs. Organic compounds with low-to-moderate molecular weights and moderate-to-high vapor pressures might be most effective oviposition stimulants for aphidophagous predators.


2020 ◽  
Vol 30 (2) ◽  
pp. 112-121 ◽  
Author(s):  
R. Umarani ◽  
M. Bhaskaran ◽  
C. Vanitha ◽  
M. Tilak

AbstractSeed is a fertilized mature ovule, which possesses an embryonic plant. When the dry, mature seeds are subjected to imbibition, they release a wide range of organic substances, which include low molecular weight carbonyl compounds (gases and volatiles) and water-soluble organic substances (enzymes and polysaccharides). The volatile organic compounds (VOCs) are molecules of low molecular weight (300 g mol−1) and high vapour pressure (0.01 kPa at 20°C) and include diverse chemical compounds. The nature and emission kinetics of volatiles produced from seeds vary, depending on the moisture content of the seeds. Orthodox seeds stored at ‘low seed moisture content’ undergo seed deterioration, predominantly due to lipid peroxidation, initiated by autoxidation or enzymatic oxidation of unsaturated or polyunsaturated fatty acids. This peroxidation leads to emission of volatile compounds. The quantity of VOCs emitted is positively correlated with the advancement of seed deterioration. With respect to the seed germination process, exposure of seeds to ‘high moisture conditions’ leads to increased respiration, triggers glycolysis and mobilization of storage reserves, resulting in the emission of volatile metabolic products. The quantity of VOCs emitted on commencement of metabolic activity in germinating seeds depends on (1) vigour status and (2) amount of storage reserves. Since it has been established that there is a significant difference between high and low vigour seeds with respect to quantity and profile of VOCs emitted, there is great potential for utilizing the VOC profile to obtain a quick and reproducible test of vigour status of crop seeds. In order to harness the VOC profile for quick assessment of vigour status of seeds, research has to be taken up to develop standard protocols for fingerprinting of VOCs for the purpose of seed vigour assessment and to fix the standard volatile biomarker(s) specific to crop and vigour status of seeds.


2015 ◽  
Vol 7 (2) ◽  
pp. 458-465 ◽  
Author(s):  
O. V. Rodinkov ◽  
G. A. Zhuravlyova ◽  
E. A. Vaskova ◽  
I. A. Platonov

Anhydrous potassium fluoride has been proposed as a novel selective moisture trapping agent for gas chromatography to remove water vapor during adsorption concentration of low molecular weight volatile organic compounds (VOCs) from moist air.


2011 ◽  
Vol 183-185 ◽  
pp. 1057-1060
Author(s):  
Li Kun Huang ◽  
Guang Zhi Wang ◽  
Jin Long Zuo

In order to investigate the characteristic of volatile organic compounds (VOCs) from wastewater treatment plant (WWTP), the air and water samples were collected. The air samples were extracted and identified by GC/MS. The atmospheric VOCs species from all WWTP units were tested. It was shown that the main fugitive sources were primary clarifier and the room of sludge dewatering. The numbers were 33 and 30. The total species of VOCs emitted varied with a range of 16 to 33. The relationship between VOCs species and the change of water quality were discussed. The increasing of VOCs species was related with the higher SUVA, and the molecular weight of VOCs species in air sample gradually become lower along the wastewater treatment process. In the wastewater treatment process,the function of microbe did not contribute the whole effort on the removing of organic pollutants. VOCs volatilized from water phase could also reduce organic pollutants in water phase. In the whole WWTP, the main VOCs species were alkyl with small molecular weight, aromatic hydrocarbon material and naphthalene. Halogenated hydrocarbon was detected in primary treatment unit and anoxic tank.


2015 ◽  
Vol 148 (4) ◽  
pp. S-483 ◽  
Author(s):  
Daniel K. Chan ◽  
Marlys Anderson ◽  
David T. Lynch ◽  
Cadman L. Leggett ◽  
Lori S. Lutzke ◽  
...  

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