Biodegradation of 2-ethylhexyl nitrate (2-EHN) by Mycobacterium austroafricanum IFP 2173

2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel which is used to comply with the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous phase liquid (NAPL), suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation as well as organic carbon measurement indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by GC/MS and was provisionally identified as 4-ethyldihydrofuran-2(3H)-one by LC-MS/MS analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolised further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability

Kairomonal response of predators to three pine bast scale sex pheromones

The kairomonal activity of the sex pheromones of three pine bast scales, Matsucoccus feytaudi, Matsucoccus josephi, and Matsucoccus matsumurae, as well as a new analog of the M. feytaudi sex pheromone, were investigated in pine forests of France, Portugal, and Italy. The response of the maritime pine bast scale predators, Elatophilus spp. and Hemerobius stigma, was used to test the influence of trapping methods, kairomone composition, and dose. Both predators showed significant attraction to all compounds except to the sex pheromone of M. josephi. Significant increase in captures was observed as a function of dose, and within the studied dose range, up to 2200 mu g, no threshold saturation limits were observed for any of the attractive compounds. Trap design and size did not significantly influence predator captures, except for high population levels of Elatophilus crassicornis, when plate traps were more efficient than delta traps. Geographic variations were found in the kairomonal responses patterns of both predators, with the M. matsumurae sex pheromone being more attractive to the oriental populations from Corsica and Italy, whereas the western populations in Aquitaine and Portugal were more attracted to the M. feytaudi sex pheromon

Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173

2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel that is used to increase the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected from among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous-phase liquid, suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation, as well as organic-carbon measurement, indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by gas chromatography/mass spectrometry and was provisionally identified as 4-ethyldihydrofuran2(3H)-one by liquid chromatography-tandem mass spectrometry analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolized further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability

Biodegradation of 2-Ethylhexyl Nitrate by Mycobacterium austroafricanum IFP 2173▿

2-Ethyhexyl nitrate (2-EHN) is a major additive of fuel that is used to increase the cetane number of diesel. Because of its wide use and possible accidental release, 2-EHN is a potential pollutant of the environment. In this study, Mycobacterium austroafricanum IFP 2173 was selected from among several strains as the best 2-EHN degrader. The 2-EHN biodegradation rate was increased in biphasic cultures where the hydrocarbon was dissolved in an inert non-aqueous-phase liquid, suggesting that the transfer of the hydrophobic substrate to the cells was a growth-limiting factor. Carbon balance calculation, as well as organic-carbon measurement, indicated a release of metabolites in the culture medium. Further analysis by gas chromatography revealed that a single metabolite accumulated during growth. This metabolite had a molecular mass of 114 Da as determined by gas chromatography/mass spectrometry and was provisionally identified as 4-ethyldihydrofuran-2(3H)-one by liquid chromatography-tandem mass spectrometry analysis. Identification was confirmed by analysis of the chemically synthesized lactone. Based on these results, a plausible catabolic pathway is proposed whereby 2-EHN is converted to 4-ethyldihydrofuran-2(3H)-one, which cannot be metabolized further by strain IFP 2173. This putative pathway provides an explanation for the low energetic efficiency of 2-EHN degradation and its poor biodegradability

Chemical identification, electrophysiological and behavioral activities of the pheromone Metamasius hemipterus (Coleoptera : Curculionidae)

International audienc

MARKING PHEROMONES OF MEGABOMBUS SYLVARUM (L.) AND M. RUDERARIUS (MULLER) MALES (HYMENOPTERA : APIDAE)

International audienc

Aggregation pheromone of Metamasius cinnamominus and interaction with Sympatric M. hemipterus (Coleoptera, Curculionidae)

International audienc

Pheromone binding proteins of the moth Mamestra brassicae : specificity of ligand binding

International audienc