عنوان مقاله [English]
نویسندگان [English]چکیده [English]
In this study 38 water and sludge samples were collected from various areas of Anzali lagoon and 100 strains were isolated when the samples were cultured in the media. Among them, only one strain showed the maximum absorption capacity (65.4 mg/g dry wt). It was tentatively called MGG-83 strain. Further investigations proved that the strain MGG-83 belonged to the genus of Bacillus. The maximum uptake of tungsten was obtained at pH 2. The tungsten taken up by the Bacillus sp. MGG-83 increased by increasing the concentration of the tungsten. At 600mg/l, the uptake was 545.6 mg/g dry wt. The uptake of tungsten within 5 min of incubation was relatively rapid and the absorption continued slowly thereafter. When sodium azide and 2,4 dinitrophenol were used, it was evident the 80% of the absorbed tungsten is independent of the metabolism and 20% depends on the metabolism. When the cells were treated by the heat, the tungsten uptake decreased to 11%. The tungsten uptake increased with increasing in biomass of dry weight of the cells (87% at 20 mg biomass; 100% at 25mg biomass). The applied temperature in the range of 20-450C did not show any significant change in the uptake.