With increasing efforts to reuse wastewater treatment plant (WWTP) products in agriculture, assessing their impact on soil-plant systems is crucial, while the effects of accompanying antibiotic residues on soil microbial communities have not yet been adequately studied. This study focuses on clarithromycin (CLR), highly present in wastewater, and investigates the CLR-degradation potential of plant-associated microorganisms. Phaseolus vulgaris plants were grown in raised beds filled with Haplic Cambisol and amended with or without WWTP products (treated wastewater, biosolid, or composted biosolid), as a source of CLR residues. The rhizosphere microbiomes after biosolid amendments was significantly enriched by Pseudomonadaceae as assessed by 16S rRNA metagenomics and cultures enriched by CLR revealed dominance of Proteobacteria. However, no degradation of CLR by microbial consortia or enrichment cultures was observed, suggesting the multiplication of CLR-resistant bacteria with other resistance mechanisms. Cultivation-based approach combined with antibiotic modulation assays and subsequent LC-MS analysis confirmed the complete CLR removal by seven phylogenetic groups of actinomycetes in vitro. The proportion of isolates indicated that the rhizosphere is a natural reservoir for CLR-inactivating microorganisms; however, the amendment of soils with WWTP products can significantly increase their abundance and diversity.

• Keywords
• Streptomyces, Antimicrobial resistance, Biodegradation, Macrolides, Micropollutants, Soil microbiome,
• MeSH
• Anti-Bacterial Agents * pharmacology   MeSH
• Phaseolus * microbiology   drug effects   growth & development   MeSH
• Phylogeny MeSH
• Clarithromycin * pharmacology   metabolism   MeSH
• Microbiota drug effects   MeSH
• Wastewater * chemistry   MeSH
• Soil Microbiology MeSH
• Rhizosphere * MeSH
• RNA, Ribosomal, 16S genetics   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Anti-Bacterial Agents * MeSH
• Clarithromycin * MeSH
• Wastewater * MeSH
• RNA, Ribosomal, 16S MeSH

Global climate changes cause water scarcity in many regions, and the sustainable use of recycled water appears crucial, especially in agriculture. However, potentially hazardous compounds such as pharmaceuticals can enter the food chain and pose severe risks. This paper aims to study the presence of selected pharmaceutical active compounds (PhACs) and their metabolites in crops grown in aeroponic conditions and evaluate the potential of PhAC plant uptake. A solvent extraction with an acidified mixture of acetonitrile and water followed by LC-HRMS was developed and validated for quantifying nine pharmaceuticals and their nine metabolites in three plants. We aimed for a robust method with a wide linear range because an extensive concentration range in different matrices was expected. The developed method proved rapid and reliable determination of selected pharmaceuticals in plants in the wide concentration range of 10 to 20,000 ng g-1 and limit of detection range 0.4 to 9.0 ng g-1. The developed method was used to study the uptake and translocation of pharmaceuticals and their metabolites in plant tissues from an aeroponic experiment at three different pH levels. Carbamazepine accumulated more in the leaves of spinach than in arugula. On the other hand, sulfamethoxazole and clindamycin evinced higher accumulation in roots than in leaves, comparable in both plants. The expected effect of pH on plants' uptake was not significant.

• Keywords
• Extraction, Pharmaceutical, Plant uptake, Soil pollution,
• MeSH
• Hydrogen-Ion Concentration MeSH
• Pharmaceutical Preparations MeSH
• Water MeSH
• Crops, Agricultural * MeSH
• Agriculture * methods   MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Pharmaceutical Preparations MeSH
• Water MeSH