20.500.12556/DiRROS-25703 Down the drain: exploring wastewater’s role in coastal microbiome transformations Background Many coastal ecosystems worldwide are impacted by wastewater discharges, which introduce nutrients, pollutants, and allochthonous microbes that can alter microbiome composition and function. Although the severity and distribution of these impacts vary across regions, their potential consequences for key ecological processes remain a concern. The resilience and functional adaptability of native coastal microbiomes are still poorly understood. To study the immediate ecological impact of wastewater discharge on a coastal seawater microbiome, we conducted short-term microcosm experiments, exposing a coastal microbiome to two types of treated wastewater: (i) unfiltered wastewater containing nutrients, pollutants, and allochthonous microbes; and (ii) filtered wastewater containing only nutrients and pollutants. Results By integrating multi-omics and metabolic assays, we show that wastewater-derived organic matter and nutrients (mostly ammonia and phosphate) did not alter the taxonomic composition of the coastal microbiota, but triggered reorganization of metabolic pathways in them. We observed enhanced metabolism of proteins, amino acids, lipids, and carbohydrates, particularly of the lineages Alteromonadales, Rhodobacterales, and Flavobacteriales. Glaciecola (Alteromonadales), a copiotroph with antagonistic traits, significantly contributed to these shifts. Conversely, allochthonous taxa like Legionellales and Pseudomonadales had minimal impact. Elevated phosphorus concentrations resulting from wastewater input reduced the synthesis of proteins linked to scavenging phosphorus from organic phosphorus compounds, including alkaline phosphatase activity in native Rhodobacterales and Flavobacteriales, with important ecological implications for phosphorus-depleted coastal ecosystems. Furthermore, the presence of wastewater caused a decline in relative abundance and metabolic activity of Synechococcus, potentially affecting carbon cycling. Yet, the coastal microbiome rapidly respired wastewater-derived dissolved organic carbon, resulting in bacterial growth efficiencies consistent with global coastal averages. Conclusions Our findings highlight the capacity of coastal microbiomes to withstand wastewater discharge, with critical implications for assessment of anthropogenic perturbations in coastal ecosystems. However, wastewater-driven changes in metabolic functions and niche utilization within the autochthonous microbial community, impacting phosphorus cycling and potentially affecting carbon cycling, may have long-term consequences for ecosystem functioning. wastewater microorganisms metagenomics metaproteomics odpadna voda mikroorganizmi metagenomika metaproteomika true false true Angleški jezik Slovenski jezik Neznano 2026-01-27 14:09:21 2026-01-27 14:09:21 2026-01-30 04:19:10 0000-00-00 00:00:00 2025 0 0 Nasl. z nasl. zaslona; Opis vira z dne 9. 1. 2026; Soavtorji: Eduard Fadeev, Mauro Celussi, Valentina Turk, Katja Klun, Leila Afjehi-Sadat, Gerhard J. Herndl & Tinkara Tinta; str. [1-50] 2025 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 2025-12-24 574.5 2049-2618 10.1186/s40168-025-02298-1 264139523 https://link.springer.com/article/10.1186/s40168-025-02298-1 1 71825660-fb81-11f0-a15d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=39017 40168_2025_2298_MOESM1_ESM.docx 40168_2025_2298_MOESM1_ESM.docx 1 397F210AB4DA1095A0A847E38DDD1E64 0ca4fb785e699b196f5a32b1b285324876e5b9914ac63e32be431880309ea1a0 d3765a4c-fb82-11f0-a15d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=39020 40168_2025_2298_MOESM2_ESM.docx 40168_2025_2298_MOESM2_ESM.docx 1 1ED9A5FE82816346F59085417583CF6D 68c5bb96a17251111b6191ea6f5a8d2333d85ae41dd734ee42dc044930aae4b1 db9a00a0-fb82-11f0-a15d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=39022 40168_2025_2298_MOESM3_ESM.xlsx 40168_2025_2298_MOESM3_ESM.xlsx 1 9F78F0501297B53C1E70CC999A4F4AE3 9c5a868e2e2f4a3756c78623e0d08299e9e3232d2f2b54cd6bdeed04c5dadd86 e39c5802-fb82-11f0-a15d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=39023 40168_2025_2298_MOESM4_ESM.xlsx 40168_2025_2298_MOESM4_ESM.xlsx 1 A8DA53A1839BFEE03A6213F026484DF0 3404b7d87969f7ce57b176abaac9c0f1b2ee00fd0eb9913bb791c835dee61bbc ec75903a-fb82-11f0-a15d-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=39024 Nacionalni inštitut za biologijo 0 0 0