Enantioselective biodegradation of pharmaceuticals, alprenolol and propranolol, by an activated sludge inoculum

• Published in: Ecotoxicology and environmental safety Vol. 87; no. 1; pp. 108 - 114
• Main Authors: Ribeiro, Ana R., Afonso, Carlos M., Castro, Paula M.L., Tiritan, Maria E.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.01.2013; Elsevier
• Subjects: Activated sludge; Adrenergic beta-Antagonists - chemistry; Adrenergic beta-Antagonists - metabolism; Alprenolol; Alprenolol - chemistry; Alprenolol - metabolism; Animal, plant and microbial ecology; Applied ecology; Assaying; beta-adrenergic antagonists; Beta-blockers; Biodegradation; Biodegradation, Environmental; Biological and medical sciences; Carbon; Chiral ecotoxicity; Chirobiotic CSP; Chromatography, High Pressure Liquid; Ecotoxicology, biological effects of pollution; enantiomers; Enantioselective biodegradation; fluorescence; Fundamental and applied biological sciences. Psychology; General aspects; high performance liquid chromatography; HPLC-FD; Inoculum; Pharmaceuticals; Pollutants; Propranolol; Propranolol - chemistry; Propranolol - metabolism; Sewage - microbiology; Standard deviation; Stereoisomerism; vancomycin; Chiral ecotoxicity; ALP; HAc; QC; S/N; t1/2; PHO; Enantioselective biodegradation; Chirobiotic CSP; Alprenolol; Propranolol; HPLC-FD; LOD; MM; CSP; EF; RSD; APIs; k; Beta-blockers; LOQ; TEA; AS; WWTP; FD; Biodegradation; Drug; Activated sludge; Ecotoxicology; Toxicity; HPLC chromatography; Chenopodiaceae; Beta; Dicotyledones; Angiospermae; Environment; Spermatophyta; Organic compounds; Inoculum
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2012.10.009

Biodegradation of chiral pharmaceuticals in the environment can be enantioselective. Thus quantification of enantiomeric fractions during the biodegradation process is crucial for assessing the fate of chiral pollutants. This work presents the biodegradation of alprenolol and propranolol using an activated sludge inoculum, monitored by a validated enantioselective HPLC method with fluorescence detection. The enantioseparation was optimized using a vancomycin-based chiral stationary phase under polar ionic mode. The method was validated using a minimal salts medium inoculated with activated sludge as matrix. The method was selective and linear in the range of 10–800ng/ml, with a R2>0.99. The accuracy ranged from 85.0 percent to 103 percent, the recovery ranged from 79.9 percent to 103 percent, and the precision measured by the relative standard deviation (RSD) was <7.18 percent for intra-batch and <5.39 percent for inter-batch assays. The limits of quantification and detection for all enantiomers were 10ng/ml and 2.5ng/ml, respectively. The method was successfully applied to follow the biodegradation of the target pharmaceuticals using an activated sludge inoculum during a fifteen days assay. The results indicated slightly higher biodegradation rates for the S-enantiomeric forms of both beta-blockers. The presence of another carbon source maintained the enantioselective degradation pattern while enhancing biodegradation extent up to fourteen percent. [Display omitted] ► HPLC enantioseparation of alprenolol and propranolol. ► Enantioselective biodegradation of beta-blockers by activated sludge consortium. ► Higher biodegradation extents of (S)-forms of both alprenolol and propranolol.