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Inhibition of a glucose-limited sequencing fed-batch culture of Salmonella enterica serovar enteritidis by volatile fatty acids representative of the ceca of broiler chickens.

The effects of concentrations of volatile fatty acids on an anaerobic, glucose-limited, and pH-controlled growing culture of Salmonella enterica serovar Enteritidis were studied. Suddenly increasing volatile fatty acids to the concentrations representative of the ceca of 15-day-old broiler chickens caused washout of serovar Enteritidis. In contrast, a sudden increase to the volatile fatty acid concentrations representative of the ceca of younger broiler chickens caused a reduction in the biomass but not washout. Gradually increasing volatile fatty acids caused a gradual decrease in the biomass of serovar Enteritidis. We conclude that the concentrations of volatile fatty acids present in the ceca of broilers with a mature microflora can cause washout of serovar Enteritidis in an in vitro system mimicking cecal ecophysiology.

Anaerobiosis↗

DETERMINATION OF STEAM-VOLATILE ORGANIC ACIDS IN FERMENTATION MEDIA BY GAS-LIQUID CHROMATOGRAPHY.

Five gas chromatographic liquid phases (25% Carbowax 20 M plus 4% H(3)PO(4), 17.5% dioctyl sebacate plus 7.5% sebacic acid, 17.5% dioctyl sebacate plus 7.5% docosanoic acid, 5% Tween 80, and 20% LAC-296 [poly (diethylene glycol adipate)] plus 2% H(3)PO(4)) were studied with respect to their utility in the separation and quantitation of steam-volatile organic acids commonly produced in fermentation. Optimal operating conditions and column stability for routine analysis were established. An Aerograph Hy-Fi gas chromatograph was used for all work, except the studies with Tween 80 in which an Aerograph A-90-C was employed. Chromatographic traces are presented of volatile fatty acid analyses with each of the liquid phases. Complete separation of all isomers of the fatty acids from C(2) to C(5) was accomplished by the Carbowax 20 M plus H(3)PO(4), dioctyl sebacate plus sebacic acid, and dioctyl sebacate plus docosanoic acid columns. The latter two liquid phases were extremely unstable and proved to be unsatisfactory for analysis of aqueous samples. A column of Carbowax 20 M + H(3)PO(4) separated steam-volatile organic acids completely. The volatile fatty acid isomers were separated by 5% Tween 80 somewhat less completely, and the peak shapes were not as sharp and symmetrical as that desired for good quantitative work. LAC-296 (20%) plus 2% H(3)PO(4) proved to be the most satisfactory of the liquid phases for routine analysis of deproteinated in vitro rumen fermentation media. The column has been used for routine analysis of rumen fermentation fluid and in vitro rumen incubation fluid. All the organic acids from C(2) to C(5), except isobutyric, could be quantitated with this column. Stability of the column with the aqueous solutions was extremely good. The standard deviation of the analysis of each volatile acid component in a fermentation fluid was less than 0.5 molar per cent. The short-chain organic acids (C(2) to C(5)) were shown to be extremely stable in aqueous solution for as long as 6 months after preparation for gas chromatographic analysis by protein precipitation with metaphosphoric acid-H(2)SO(4) and refrigeration at 4 C in stoppered tubes.

Animals↗

Detection of anaerobic wound infection by analysis of pus swabs for volatile fatty acids by gas-liquid chromatography.

Swabs were able to absorb enough extractable volatile fatty acids from broth cultures of anaerobic organisms for detection and analysis by gas-liquid chromatography (GLC). Similarly, volatile fatty acids were often detected in swabs dipped into liquid pus. Fifty-three liquid pus specimens were then investigated fully to determine if GLC analysis of swab samples gave the same result as microbial culture of the specimens and GLC analysis of the liquid pus. Anaerobic bacteria failed to grow from 36 and volatile fatty acids were not extracted from swabs of 31 of these pus samples but were extracted from swabs of five. Anaerobic bacteria were isolated from 17 of the specimens, and in 15, volatile fatty acids were also detected in the swab samples; in two, volatile fatty acids were absent from both swab samples and liquid pus. In this study, results by culture and GLC analysis of swabs were similar in 87% of specimens.

Anaerobiosis↗

Volatiles of Pseudomonas aeruginosa and related species by automated headspace concentration--gas chromatography.

The volatile metabolites of three strains of Pseudomonas aeruginosa and one strain each of Pseudomonas cepacia, Pseudomonas maltophilia, Pseudomonas fluorescens, and Pseudomonas putida were analyzed using an automated headspace concentrator incorporating a gas chromatograph. The procedure does not require sample preparation and automates the entire analytical sequence to yield reproducible profiles of volatile constituents. Gas chromatographic profiles of the volatile metabolites of each species were obtained using a 20-min concentration period and two fused silica capillary columns of different polarities. The production of headspace metabolites from trypticase soy broth was studied in relationship to culture incubation time and initial cell concentration. The volatiles identified after 24 h incubation consisted of 1-butanol, isopentanol, toluene, 1-undecene, 2-butanone, 2-heptanone, 2-nonanone, and 2-undecanone. Sufficient amounts of specific metabolites were produced after 5 h incubation to provide information of possible diagnostic value. In particular, all P. aeruginosa strains produced a distinctive series of 1-undecene and methyl ketones after 5 h incubation of media inoculated to provide 2 X 10(6) cells/mL. The results indicate that when growth and analytical conditions are held constant, P. aeruginosa and related species produce characteristic profiles of headspace metabolites. Since conventional bacteriological tests require 24 h or more for the identification of these pseudomonads, automated volatile analysis could provide an alternative means for the rapid detection of these bacteria.

Chromatography, Gas↗

Impact of concentration, temperature, and pH on inactivation of Salmonella spp. by volatile fatty acids in anaerobic digestion.

It is known that the presence of volatile fatty acids may play a role in the inactivation of pathogens for systems that employ an acid phase reactor. This study was conducted to investigate the influence of volatile fatty acids on the inactivation of Salmonella spp. over a range of digestion temperatures. In this study, digesters that were treating municipal wastewater treatment plant sludges were operated at temperatures that ranged from 35 to 49 degrees C and had a solids residence time of 15 days. Samples collected from the effluent of the digesters were dosed with solutions containing acetic, propionic, and butyric acids alone and in mixtures, and the dosed effluents were analyzed for Salmonella spp. over time. In the first round of testing, the digester effluents were dosed with individual organic acids and also a mixture containing all three volatile fatty acids over a range of concentrations from 750 to 6000 mg/L, and the pH of the samples was fixed at a value of 5.5. In the second round of testing, the sample sludges were spiked with a fixed amount of organic acid mixture, and the pH was varied from 4.5 to 7.5. The reduction of Salmonella spp. in digester effluents, when dosed with volatile organic acids, was found to depend on pH, temperature, the chain length of the acids, and the concentration and composition of the acids present. Increases in temperature appeared to increase the inhibitory effects of the volatile organic acids. At mesophilic temperatures, acidic pHs resulted in a greater inhibition of Salmonella spp.; whereas at higher temperatures neutral pHs were found to be more inhibitory. The results suggest that acid phase digesters that operate at elevated temperatures and low pH can achieve substantial reduction of Salmonella spp.

Anaerobiosis↗

Pathology of volatile substance abuse: a case report and a literature review.

The medicolegal importance of volatile substance abuse, as an example of toxicological deaths, is reviewed. A case of a 13-year-old boy who died after inhalation of volatile substances from a deodorant spray tin is presented. Another similar case has been summarized in the discussion. Different aspects of volatile substance abuse are considered with special emphasis on those facets which are relevant to forensic pathology practice. The most important pathological alterations associated with the acute and chronic abuse of volatile substances are discussed and some histological features of these conditions are illustrated with photographs. These include some microscopic changes of the central nervous system, respiratory system and the kidneys. The roles of the pathologist and the toxicologist in the investigations of the fatalities resulting from the volatile substance abuse are reviewed and practical points are explained. Lastly, some relevant legal points are discussed.

Adolescent↗

Analysis of the volatile components of five Turkish Rhododendron species by headspace solid-phase microextraction and GC-MS (HS-SPME-GC-MS).

Volatile constituents of various solvent extracts (n-hexane, CH2Cl2, H2O) of 15 different organs (leaves, flowers, fruits) of five Rhododendron species (Ericaceae) growing in Turkey were trapped with headspace solid-phase microextraction (HS-SPME) technique and analyzed by GC-MS. A total of 200 compounds were detected and identified from organic extracts, while the water extracts contained only traces of few volatiles. The CH2Cl2 extract of the R. luteum flowers was found to exhibit the most diverse composition: 34 compounds were identified, with benzyl alcohol (16.6%), limonene (14.6%) and p-cymene (8.4%) being the major compounds. The CH2Cl2-solubles of R. x sochadzeae leaves contained only phenyl ethyl alcohol. This study indicated appreciable intra-specific variations in volatile compositions within the genus. Different anatomical parts also showed altered volatile profiles. This is the first application of HS-SPME-GC-MS on the volatiles of Rhododendron species.

Benzyl Alcohol↗

An infrared evanescent wave sensing system coupled with a hollow fiber membrane for detection of volatile organic compounds in aqueous solutions.

We have developed an on-line sensing method for the detection of volatile organic compounds (VOCs) in contaminated aqueous solutions by combining a microporous hollow fiber membrane with an infrared (IR) sensing system. Polypropylene microporous hollow fibers were used to separate the VOCs from the aqueous solution into the hollow fibers, which were purged countercurrently for detection by the IR sensing systems. An evanescent-wave-type IR sensing system was used to detect the VOCs that were purged from the hollow fibers. The sensing element was coated with polyisobutylene (PIB) to concentrate the VOCs for their detection. To study the performance of this system, we examined a number of factors, such as the purging flow rate, the sample flow rate, and the volatilities of the VOCs. The results indicate that an increase in the purging flow rate reduces the analytical signal significantly, especially for purging flow rates >2 mL/min. The pumping flow rate for the aqueous sample also influenced the analytical signals, but far less sensitively. The volatilities of the examined compounds also affected the analytical signals: the higher the volatility of the compound, the lower the intensity of the analytical signals and the shorter the time required to reach the equilibrium signal. From an examination of the dynamic range of this proposed method, a regression coefficient >0.994 was obtained for concentrations below 250 mg/L, even under non-equilibrium conditions. The response time of the system was studied in an effort to examine the suitability of using this sensing method for automatic detection. The results indicate that new equilibrium conditions were established within 3 min for highly volatile compounds, which suggests that on-line monitoring of the levels of VOCs can be performed in the field.

Membranes, Artificial↗

Ammonia volatilization from surface-applied poultry litter under conservation tillage management practices.

Land application of poultry litter can provide essential plant nutrients for crop production, but ammonia (NH(3)) volatilization from the litter can be detrimental to the environment. A multiseason study was conducted to quantify NH(3) volatilization rates from surface-applied poultry litter under no-till and paraplowed conservation tillage managements. Litter was applied to supply 90 to 140 kg N ha(-1). Evaluation of NH(3) volatilization was determined using gas concentrations and the flux-gradient gas transport technique using the momentum balance transport coefficient. Ammonia fluxes ranged from 3.3 to 24% of the total N applied during the winter and summer, respectively. Ammonia volatilization was rapid immediately after litter application and stopped within 7 to 8 d. Precipitation of 17 mm essentially halted volatilization, probably by transporting litter N into the soil matrix. Application of poultry to conservation-tilled cropland immediately before rainfall events would reduce N losses to the atmosphere but could also increase NO(3) leaching and runoff to streams and rivers.

Agriculture↗

A solid-phase microextraction chamber method for analysis of manure volatiles.

Odors from livestock operations are a complex mixture of volatile carbon, sulfur, and nitrogen compounds. Currently, detailed volatiles analysis is both time consuming and requires specialized equipment and methods. This work describes a new method that utilizes a dynamic flux chamber, solid-phase microextraction (SPME), and gas chromatography-mass spectroscopy (GC-MS) to describe and compare the odorous compounds emitted from cattle and swine feces. Evaluation of method parameters produced a protocol for comparing relative emissions based on fixed sample temperature (20 degrees C) and exposed surface area (approximately 523 cm(2)), air flow rates (1 L min(-1) or 16 cm s(-1)), SPME exposure time (5 min), and chamber cleaning procedures (70% ethanol rinse and drying for 30 min at 105 degrees C) to minimize cross-contamination between samples. A variety of volatile organic compounds (VOCs) including alcohols, volatile fatty acids, aromatic ring compounds, ketones, esters, and sulfides were routinely detected and the relative emissions from fresh and incubated (37 degrees C overnight) swine and cattle feces were compared as a measure of potential to produce odorants during manure storage. Differences in the types and relative quantities of volatiles emitted were detected when animal species (cattle or swine), diet, fecal incubation, or sample storage conditions (20, 4, or -20 degrees C) were varied.

Animals↗

Volatile compounds produced in cheese by Enterobacteriaceae strains of dairy origin.

The formation of volatile compounds in fresh cheese by 10 Enterobacteriaceae strains of dairy origin (4 Hafnia alvei, 2 Serratia liquefaciens, 1 Enterobacter cloacae, 1 Enterobacter sakazakii, and 2 Escherichia coli strains) was investigated. Small cheeses were made from pasteurized cow's milk separately inoculated with 1-3 x 10(3) CFU/ml of each of the Enterobacteriaceae strains, with glucono-8-lactone added to achieve a pH value of 5.2 in the curds. All strains reached counts close to 10(8) CFU/g in 1-day-old cheeses and survived well from day 1 to day 8. Cheeses were analyzed for volatile compounds by gas chromatography-mass spectroscopy, after extraction by dynamic headspace using a purge and trap apparatus. Sixty-one volatile compounds were determined in cheeses, 31 of which were further investigated. Significant increases of aldehydes, sulfur compounds, and aromatic compounds were recorded from 2-h curd to 1-day-old cheese, and of ketones, alcohols, and acids from 2-h curd to 8-day-old cheese. Acetaldehyde, 2-methyl propanal, and 3-methyl butanal predominated among aldehydes; 2,3-butanedione, 2,3-pentanedione, and 3-hydroxy 2-butanone among ketones; ethanol, 2-methyl propanol, and 3-methyl butanol among alcohols; and ethyl acetate among esters. Hierarchical cluster analysis of strains using the data of 31 volatile compounds separated clearly the strain of E. sakazakii, which produced high amounts of volatile compounds, from the other Enterobacteriaceae strains.

Aldehydes↗

[Study of the extraction technique of volatile oil from Chinese herbs for manufacturing Xiaoerjianpixiaoshi oral solution].

OBJECTIVE: To determine the optimal extracting technique for the volatile oil from the Chinese herbs for manufacturing Xiaoerjianpixiaoshi oral solution. METHODS: Two steam distillation processes were carried out to extract the volatile oil from three Chinese herbs. UV-spectrophotometry method was used to determine the oil content in the distillate, and the mathematical model was established according to volatile oil distillation process by exponential curve regression analysis. RESULT: Direct extraction of the oil by means of steam distillation process was more workable, and the decrement of oil content conformed well with the exponential model. Collection of 2 volumes of the distillate resulted in the yield of volatile oil of 61.64%. CONCLUSION: The optimal extraction of the volatile oil can be resulted from immersion of the drugs in 8 volumes of water for 0.5 h and collection of 2 volumes of the distillate.

Administration, Oral↗

[Effects of rice volatile infochemicals on insects].

Plant volatile is not only the key of the relationship among plant, herbivore and its natural enemy, but also the foundation for the theory and practice of pest manage. In this paper, the chemical characteristic of rice volatile and its function among herbivore and its natural enemy were reviewed. The application and development direction of rice volatile infochemicals were proposed. Two directions to study the rice volatile infochemicals, which could be used in pest control, were also discussed. One was the physiology and biochemistry of little molecule signals, which was the key of rice second metabolize, and the other was the base of sense, identify and learn of pest insect to rice volatile infochemicals.

Animals↗

[Analysis of chemical constituents of volatile oil in Armeniaca mume Sieb from different habitats by gas chromatography-mass spectrometry].

OBJECTIVE: To analyse chemical constituents of volatile oil in Armeniaca mume Sieb. METHODS: After stream distillation, the volatile oil was extracted with ether and concentrated. Then it was analysed by gas chromatography/mass spectrometry. RESULT: More than 70 different compounds were separated and identified from the volatile oil in A. mume. The identified constituents from each kind of A. mume represent about 90% of the total volatile oil. CONCLUSION: The main compounds of the volatile oil in A. mume were hexadecanoic acid, linoleic acid, benzoic acid, furfural, benzaldehyde, benzenemethanol, etc.

Benzaldehydes↗

[Changes of amino acid content in hippocampus of epileptic rats treated with volatile oil of Acorus tatarinowii].

OBJECTIVE: To study the changes of excitatory and inhibitory amino acid content in hippocampus of epileptic rats treated with volatile oil of A. tatarinowii, and explore the possible antiepiletic mechanism. METHOD: The volatile oil was extracted through Supercritical-CO2 Fluid Extraction (SFE-CO2), and epileptic models were built up by kainic acid (KA) lateral ventricle injection. The content of amino acid in hippocampus of epileptic rats treated with volatile oil was calculated. RESULT: The content of GABA increased and Glu decreased prominently (P < 0.05) after volatile oil 35 mg x kg(-1) intraperitoneal injection. CONCLUSION: The volatile oil of A. tatarinowii can modulate the balance of excitatory and inhibitory amino acid in epileptic rats, thereby exerting its antiepileptic effect.

Acorus↗

[Plant volatiles and their metabolic engineering].

Plant volatiles mainly include terpenoid, benzenoid/phenylpropanoid and fatty-acid derivatives, and they play diverse roles in plant-plant and plant-insect communications. In recent years, great progress has been made in biochemical and molecular characterization of the formation and release of these volatiles, and this make it possible to dissect their biological functions. More than 30 kinds of genes related with biosynthesis of these volatiles have been cloned. The pathways leading to synthesis of these metabolites can be controlled by enzyme activity and the substrates available as well as gene architecture. Plant volatiles can serve as attractants for specific pollinators, important cellular regulators in developmental processes and protection against environmental stress, whereas those released after herbivory or pathogen attacks can induce the expression a set of defensive genes or attraction of predators of the herbivores. An attractive prospect in this area is to design scent spectrum of plant with genetic and molecular technology. Two alternative approaches are used to genetically engineer these plant volatiles. One is based on the introduction of foreign genes encoding enzymes with activities that are missing in target plant, while the other is focused on modulating the expression of native genes.

Cloning, Molecular↗

Volatilization behaviors of diesel oil from the soils.

The volatilization of diesel oil, Shengli crude oil and 90 # gasoline on glass surface of petri dishes were conducted at the ambient temperature of 25 degrees C. Diesel oil evaporates in a power manner, where the loss of mass is approximately power with time. 90 # gasoline evaporates in a logarithmic with time. Where as the volatilization of Shengli crude oil fit either the logarithmic or power equation after different time, and has similar R2. And the effects of soil type and diesel oil and water content on volatilization behavior in unsaturated soil were studied in this paper. Diesel oil and water content in the soils play a large role in volatilization from soils. Appropriate water helps the wicking action but too much water stops it. The wicking action behaves differently in four different types of soils in the same volatilization experiment of 18% diesel oil content and air-dry condition.

Air Pollutants↗

[Investigation on the nitrogen functionality of volatile through FTIR spectroscopy equipped with a long path distance gas cell].

Nitrogen functionalities of volatile of three different rank coals, namely TONGCHUAN lean coal, SHENMO bituminite and YIBIN anthracite, were studied by using Fourier transform infrared spectroscopy (FTIR) equipped with 16 m long path distance gas cell. The detection problem of low content of nitrogen in volatile was successfully solved because of the application of the long path distance gas cell. In the long path distance gas cell, the infrared penetrates the sample more times than in a normal gas cell. Results from the analysis of spectra obtained by FTIR show that there are four functionalities of nitrogen in volatile, including pyrrole-type nitrogen, pyrindine-type nitrogen, pyridine-N-oxide nitrogen, and nitrile nitrogen. Comparison of research results of nitrogen group between coal and volatile suggests that the difference in fate of nitrogen between volatile and coal results from the macromolecular nitrogen group of coal decomposition under the effect of temperature.

Coal↗