Wax Ester Analysis of Bats Suffering from White Nose Syndrome in Europe.

The composition of wax esters (WE) in the fur of adult greater mouse-eared bats (Myotis myotis), either healthy or suffering from white nose syndrome (WNS) caused by the psychrophilic fungus Pseudogymnoascus destructans, was investigated by high-resolution mass spectrometry analysis in the positive ion mode. Profiling of lipid classes showed that WE are the most abundant lipid class, followed by cholesterol esters, and other lipid classes, e.g., triacylglycerols and phospholipids. WE abundance in non-polar lipids was gender-related, being higher in males than in females; in individuals suffering from WNS, both male and female, it was higher than in healthy counterparts. WE were dominated by species containing 18:1 fatty acids. Fatty alcohols were fully saturated, dominated by species containing 24, 25, or 26 carbon atoms. Two WE species, 18:1/18:0 and 18:1/20:0, were more abundant in healthy bats than in infected ones.

Extraction of brewer's yeasts using different methods of cell disruption for practical biodiesel production.

The methods of preparation of fatty acids from brewer's yeast and its use in production of biofuels and in different branches of industry are described. Isolation of fatty acids from cell lipids includes cell disintegration (e.g., with liquid nitrogen, KOH, NaOH, petroleum ether, nitrogenous basic compounds, etc.) and subsequent processing of extracted lipids, including analysis of fatty acid and computing of biodiesel properties such as viscosity, density, cloud point, and cetane number. Methyl esters obtained from brewer's waste yeast are well suited for the production of biodiesel. All 49 samples (7 breweries and 7 methods) meet the requirements for biodiesel quality in both the composition of fatty acids and the properties of the biofuel required by the US and EU standards.

Induction of conidiation by endogenous volatile compounds in Trichoderma spp.

Light and starvation are two principal environmental stimuli inducing conidiation in the soil micromycete Trichoderma spp. We observed that volatiles produced by conidiating colonies of Trichoderma spp. elicited conidiation in colonies that had not been induced previously by exposure to light. The inducing effect of volatiles was both intra- and interspecific. Chemical profiles of the volatile organic compounds (VOCs) produced by the nonconidiated colonies grown in the dark and by the conidiating colonies were compared using solid-phase microextraction of headspace samples followed by tandem GC-MS. The conidiation was accompanied by increased production of eight-carbon compounds 1-octen-3-ol and its analogs 3-octanol and 3-octanone. When vapors of these compounds were applied individually to dark-grown colonies, they elicited their conidiation already at submicromolar concentrations. It is concluded that the eight-carbon VOCs act as signaling molecules regulating development and mediating intercolony communication in Trichoderma.

Volatile organic compounds: sampling methods and their worldwide profile in ambient air.

The atmosphere is a particularly difficult analytical system because of the very low levels of substances to be analysed, sharp variations in pollutant levels with time and location, differences in wind, temperature and humidity. This makes the selection of an efficient sampling technique for air analysis a key step to reliable results. Generally, methods for volatile organic compounds sampling include collection of the whole air or preconcentration of samples on adsorbents. All the methods vary from each other according to the sampling technique, type of sorbent, method of extraction and identification technique. In this review paper we discuss various important aspects for sampling of volatile organic compounds by the widely used and advanced sampling methods. Characteristics of various adsorbents used for VOCs sampling are also described. Furthermore, this paper makes an effort to comprehensively review the concentration levels of volatile organic compounds along with the methodology used for analysis, in major cities of the world.

Breakthrough characteristics of volatile organic compounds in the -10 to + 170 degrees C temperature range on Tenax TA determined by microtrap technology.

In this work the breakthrough volumes (BTVs) of volatile organic compounds (VOCs) on Tenax TA were determined in the -10 to 170 degrees C temperature range by using microtrap (MT) technology. The MT technology allowed experimental investigation of the temperature dependence of BTVs. Along with the BTV data, we also discuss the thermodynamics of the temperature dependence of the BTV through a two-parameter equation In (BTV) = A1/T + C1 where T is temperature (K), A1 = -deltaH/R where deltaH is enthalpy of sorption and C1 is constant. This equation fitted well the experimental results with R2 values between 0.9737 (acetone) and 0.9995 (dimethyl disulfide), with n between 6 and 11. However, for n-pentane, n-hexane and 1-hexene it proved that a three parameter equation In (BTV) = A2/ T + BTB + C2 fitted better to the experimental results, with A2 = -deltaHT0/R, B = deltaCp/R, TB = 1n(T/T0) + (T0 - T)/T, C2 a constant, deltaHT0 the adsorption enthalpy at reference temperature T0 and deltaCp the difference in the molar heat capacity of compound under investigation between the sorbed and the free gas phase state. The statistical analysis showed for example for n-pentane now R2 = 0.9969 instead of R2 = 0.9746, and Fisher statistics F = 487 instead of F = 153, with a significance level P = 0.018 for the third parameter. The results show that microtrap technology well serves as a technology to get information on temperature dependence of BTVs in an extended range. Simultaneously, it turns out that MT technology, extending the operational temperature range, is well served by a careful investigation of the temperature dependence models of BTVs.