ABSTRACT
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.
Subject(s)
Bacteria/classification , Bacteria/genetics , Bacteria/isolation & purification , Bacteria/metabolism , Biodegradation, Environmental/classification , Biodegradation, Environmental/genetics , Biodegradation, Environmental/isolation & purification , Biodegradation, Environmental/metabolism , Carbaryl/classification , Carbaryl/genetics , Carbaryl/isolation & purification , Carbaryl/metabolism , Ecosystem/classification , Ecosystem/genetics , Ecosystem/isolation & purification , Ecosystem/metabolism , Insecticides/classification , Insecticides/genetics , Insecticides/isolation & purification , Insecticides/metabolism , Middle East/classification , Middle East/genetics , Middle East/isolation & purification , Middle East/metabolism , Soil Microbiology/classification , Soil Microbiology/genetics , Soil Microbiology/isolation & purification , Soil Microbiology/metabolism , Soil Pollutants/classification , Soil Pollutants/genetics , Soil Pollutants/isolation & purification , Soil Pollutants/metabolismABSTRACT
Dual counter-current chromatography (dual CCC) has been successfully applied to rapid sample preparation for the simultaneous determination of residual carbaryl, fenobucarb and methomyl in vegetable oil and citrus fruit. The citrus fruit samples were extracted with n-hexane solution containing stable isotopically labeled internal standards (methomyl-d3, fenobucarb-d3 and carbaryl-d9), and applied to dual CCC using a two-phase solvent system of n-hexane-acetonitrile to purify the carbamate pesticides from aliphatic sample matrix. The coiled column was rotated at 420 rpm, the lower mobile phase was introduced through the head toward the tail, and the upper mobile phase in the opposite direction. Due to the high partition efficiency of dual CCC, the lower phase fraction collected from 2 to 5 min after injection could be subjected to flow-injection tandem mass spectrometry directly after concentration. Repetitive sample injection can be performed at high reproducibility without a risk of contamination from the compounds retained in the column.