RESUMO
Carbaryl is an important and widely used insecticide that pollutes soil and water systems. Bacteria from the local soil ecosystem of the Gaza Strip capable of utilizing carbaryl as the sole source of carbon and nitrogen were isolated and identified as belonging to Bacillus, Morganella, Pseudomonas, Aeromonas and Corynebacterium genera. Carbaryl biodegradation by Bacillus, Morganella and Corynebacterium isolates was analyzed in minimal liquid media supplemented with carbaryl as the only source of carbon and nitrogen. Bacillus and Morganella exhibited 94.6% and 87.3% carbaryl degradation, respectively, while Corynebacterium showed only moderate carbaryl degradation at 48.8%. These results indicate that bacterial isolates from a local soil ecosystem in the Gaza Strip are able to degrade carbaryl and can be used to decrease the risk of environmental contamination by this insecticide.
Assuntos
Bactérias/metabolismo , Carbaril/metabolismo , Inseticidas/metabolismo , Poluentes do Solo/metabolismo , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Ecossistema , Oriente Médio , Microbiologia do SoloRESUMO
Abstract Carbaryl is an important and widely used insecticide that pollutes soil and water systems. Bacteria from the local soil ecosystem of the Gaza Strip capable of utilizing carbaryl as the sole source of carbon and nitrogen were isolated and identified as belonging to Bacillus, Morganella, Pseudomonas, Aeromonas and Corynebacterium genera. Carbaryl biodegradation by Bacillus, Morganella and Corynebacterium isolates was analyzed in minimal liquid media supplemented with carbaryl as the only source of carbon and nitrogen. Bacillus and Morganella exhibited 94.6% and 87.3% carbaryl degradation, respectively, while Corynebacterium showed only moderate carbaryl degradation at 48.8%. These results indicate that bacterial isolates from a local soil ecosystem in the Gaza Strip are able to degrade carbaryl and can be used to decrease the risk of environmental contamination by this insecticide.
Assuntos
Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biodegradação Ambiental/classificação , Biodegradação Ambiental/genética , Biodegradação Ambiental/isolamento & purificação , Biodegradação Ambiental/metabolismo , Carbaril/classificação , Carbaril/genética , Carbaril/isolamento & purificação , Carbaril/metabolismo , Ecossistema/classificação , Ecossistema/genética , Ecossistema/isolamento & purificação , Ecossistema/metabolismo , Inseticidas/classificação , Inseticidas/genética , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Oriente Médio/classificação , Oriente Médio/genética , Oriente Médio/isolamento & purificação , Oriente Médio/metabolismo , Microbiologia do Solo/classificação , Microbiologia do Solo/genética , Microbiologia do Solo/isolamento & purificação , Microbiologia do Solo/metabolismo , Poluentes do Solo/classificação , Poluentes do Solo/genética , Poluentes do Solo/isolamento & purificação , Poluentes do Solo/metabolismoRESUMO
A sensitive, rapid and inexpensive analysis method has been developed for the triazines most frequently used in Palestine; the method includes fluorodensitometric screening and densitometric determination of the individual substances. Terbutryn as a model substance was derivatized with dansyl chloride in sodium hydrogen-carbonate or phosphate buffer solution to yield a green-blue fluorescent compound. Derivatization occurred at 120 degrees C within maximum of 10-min reaction time. The fluorescent compound formed was separated from excess reagent and other by-products on silica gel TLC plates and was then determined fluorodensitometrically. A linearity range between 20 and 1200 pg/spot was achieved. The method was also applied to other triazine herbicides such as ametryn, atrazine, propazine, terbuthylazine and simazine. Drinking water samples spiked with triazines were extracted using RP-C18 polar plus cartridges, and the extract could be then dansylated as a total. Recoveries were between 88% and 95%; the detection limit was 10 pg/spot and could be further improved to 2 pg/spot by a dipping solution. For quantification, each of the six triazines can be separated on one of three different stationary phases after solid phase extraction and measured densitometrically. The LOD for each individual triazine was 100 ng/l.
