کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5520566 | 1544903 | 2017 | 6 صفحه PDF | دانلود رایگان |
- Aspergillus niger AN 400 tolerates atrazine concentrations of 30 mg Lâ1.
- Aspergillus niger could degrade ATZ in the absence of a co-substrate, 40%.
- Better ATZ removal was obtained with 3.0 g Lâ1 of glucose, 72%.
- Higher glucose concentrations lead to competition between ATZ and glucose.
- 46% of detoxification was achieved by the proposed treatment.
This research aims to evaluate the ability of the fungal specie Aspergillus niger AN 400 to metabolize atrazine (ATZ) in model wastewaters, as most of the research with this worldwide used herbicide is focused on bacteria and on soil bioremediation. Firstly, the tolerance of A. niger for ATZ was evaluated in petri dishes. A. niger growth in all the tested ATZ concentrations, up to 30 mg Lâ1. Biodegradation of ATZ was then conducted in batch reactors of 3 L, with dispersed fungal biomass. Reactors were operated for 8 days at different conditions: without glucose (RG0) and glucose at concentrations of 0.5; 1.0; 2.0; 3.0; 4.0 and 5.0 g Lâ1 - RG0.5; RG1; RG2; RG3; RG4 and RG5, respectively. Control (RC) includes a reactor in the absence of fungal spores. The highest ATZ removal, 72%, occurred in RG3. At higher glucose concentration, substrate competition kinetics may be the responsible for the decrease of biodegradation rate constants. Only 50% of Chemical Oxygen Demand (COD) removal was obtained due to the presence of methanol used to dissolve ATZ, which has contributed for most of the COD in reactors. Detoxification of the ATZ solution by the biological treatment was observed by the Allium test.
Journal: Biocatalysis and Agricultural Biotechnology - Volume 9, January 2017, Pages 162-167