The 4α-Cu IITAPc SAM modified GCE exhibits an excellent electrocatalytic activity toward caffeine.
Caffeinated culture Pc#
The 4α-Cu IITAPc SAM modified GCE shows two pairs of redox waves at 0.16 V and 0.23 V, corresponding to Cu II/Cu I and Pc −1/Pc −2, respectively. This article reports the electrochemical determination of caffeine in the presence of paracetamol (PA) using a self-assembled monolayer (SAM) of non-peripheral amine substituted copper(II) phthalocyanine (4α-Cu IITAPc) on glassy carbon electrode (GCE).
This method also eliminates the harsh reaction conditions and environmental issues associated with the chemical process. This is the first report of theobromine production via a metabolically engineered strain, with the highest yield and purity reported of any biological method. Purity of the product was identical to an authentic standard as judged by LC-MS and NMR. Final yield was 80% relative to caffeine. The reaction was scaled up to 2 L and theobromine was separated and recovered in nearly 100% pure form via preparative chromatography and drying. Strain pAD1dDD containing one copy of ndmA and three copies of ndmD in two compatible plasmids, gave the best results (98.5% molar conversion of caffeine to theobromine). coli engineered with multiple combinations of the two N-demethylase genes were compared for growth and activity. The N 1-demethylase genes used in this study were originally discovered in Pseudomonas putida CBB5. This study reports bench-scale feasibility study for production and recovery of theobromine from caffeine using metabolically engineered E. Furthermore, using genome-centric analysis, we observed previously unidentified degrading strains, e.g., Piscinibacter, Hydrogenophaga, and Rubrivivax for caffeine transformation, and Methylophilus and Methyloversatilis for atenolol transformation. Integrated analysis of metagenomic reads and transformation products of micropollutants showed a shift in caffeine oxidation and demethylation pathways at different EBCTs, simultaneous occurrence of atrazine hydrolysis and oxidation pathways, and sulfadiazine and sulfamethoxazole oxidation in the filters. In contrast, the removal of other six micropollutants (i.e., naproxen, carbamazepine, atrazine, trimethoprim, sulfamethoxazole, and sulfadiazine) in the filters were less than 27.1% at shorter EBCTs, but significantly increased at EBCT = 4 h, indicating the dominant role of microbial biotransformation in these micropollutants removal. Under seven different empty bed contact times (EBCTs), the column experiments showed that caffeine and atenolol were easily removed (up to 92.1% and 97.6%, respectively) with adsorption and microbial biotransformation of the filters.
Here, we constructed sand filter columns filled with manganese or quartz sand obtained from full-scale DWTPs to explore the biotransformation of eight micropollutants. The mixed culture does not accept theophylline(1,3-dimethylxanthine), theobromine(3,7-dimethylxanthine), and paraxanthine(1,7-dimethylxanthine) as the carbon source.Īlthough there is growing evidence that micropollutants can be microbially converted in rapid sand filters of drinking water treatment plants (DWTPs), little is known about the biotransformation pathways and associated microbial strains in this process. Oxygen uptake studies indicated that caffeine(I) grown cells oxidized TMU(II), TMA (III), glyoxalic acid (VI), dimethylurea(VII), and monomethylurea(V), but not monomethyl and dimethyluric acids. Further degradation of TMA (III) by caffeine grown cells yields dimethylurea (VII) as one of the metabolites. Both TMU and TMA are hitherto not shown to be formed in the microbial system. The mixed culture does not initiate degradation by N-demethylation either complete or partial, but instead carries out oxidation at the C-8 position resulting in the formation of 1,3,7-trimethyluric acid (TMU, II) which further gets degraded to 3,6,8-trimethylallantoin (TMA, III). A new oxidative pathway for the degradation of caffeine(1,3,7-Trimethylxanthine, I) by a mixed culture consisting of strains belonging to the genera Klebsiellaand Rhodococcusis presented.
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