Microbiome and chemistry insights into two oligotrophic karst water springs in Slovenia from 2016 and 2023 perspectives

Likar, Mojca (author), Blagojevič, Marko (author), Ošlak, Maša (author), Mikoš, Matjaž (author), Prevoršek, Zala (author), Holko, Ladislav (author), Ribič, Dragana (author), Likozar, Blaž (author), Novak, Uroš (author), Murovec, Boštjan (author), Kolbl Repinc, Sabina (author), Stres, Blaž (author)

Groundwater, a critical source of drinking water, plays an essential role in global biogeochemical cycles, yet its microbial ecosystems remain insufficiently characterized, particularly in pristine karst aquifers. This study conducted high-resolution profiling of microbial communities and environmental parameters in two representative alpine karst aquifers in Slovenia: Idrijska Bela and Krajcarca. Monthly groundwater samples from the Krajcarca spring and Idrijska Bela borehole over a 14-month period were analyzed using wholemetagenome sequencing (WMS), UV-Vis spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and isotopic analysis. The results revealed stable hydrochemical conditions with clear spatial differences driven by bedrock composition and groundwater residence time. Bacterial communities displayed strong correlations with hydrochemical parameters, while archaeal communities exhibited temporal stability. Functional gene profiles mirrored bacterial patterns, emphasizing the influence of environmental gradients on metabolic potential. No significant temporal changes were detected across two sampling campaigns (2016–2023), highlighting the resilience of these aquifers. This work establishes a valuable baseline for understanding pristine groundwater microbiomes and informs future monitoring and water quality management strategies.

• Language: English
• Keywords: pristine karst aquifers, groundwater microbiome, whole-metagenome sequencing, microbial diversity, functional gene profiles, hydrogeochemistry, carbonate weathering, drinking water quality, ecological resilience, sustainable groundwater management
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Publication date: 14.08.2025
• Year: 2025
• Number of pages: 25 str.
• Numbering: Vol. 17, issue 16, [article no.] 2402
• PID: 20.500.12556/RUL-171176
• UDC: 579
• ISSN on article: 2073-4441
• DOI: 10.3390/w17162402
• COBISS.SI-ID: 245738243
• Publication date in RUL: 18.08.2025

Record is a part of a journal

• Title: Water
• Shortened title: Water
• Publisher: MDPI
• ISSN: 2073-4441
• COBISS.SI-ID: 36731653

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.

Secondary language

• Language: Slovenian
• Keywords: mikrobiologija, olipotrofni vodni izviri, kras, mikrobiom, kemijska sestava, Slovenija

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0180-2022
• Name: Vodarstvo in geotehnika: orodja in metode za analize in simulacije procesov ter razvoj tehnologij

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0095-2020
• Name: Vzporedni in porazdeljeni sistemi