Andreea Oarga-Mulec

University of Nova Gorica

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Janez Mulec

Research Centre of the Slovenian Academy of Sciences and Arts

Tjaša Griessler Bulc

University of Ljubljana

Petter D. Jenssen

Norwegian University of Life Sciences

Sara Skok

Research Centre of the Slovenian Academy of Sciences and Arts

Aleksandra Krivograd Klemenčić

Slovenian Environment Agency

Ladislav Holko

Slovak Academy of Sciences

Tina Eleršek

National Institute of Biology

Matjaž Valant

University of Nova Gorica

Lejla Pašić

Sarajevo School of Science and Technology

Tadeja Matos

University of Ljubljana

Cooperative Institutions

University of Ljubljana

University of Nova Gorica

Ljubljana University Medical Centre

Jožef Stefan Institute

Jožef Stefan International Postgraduate School

School Centre Nova Gorica

Health Insurance Institute of Slovenia

Research Centre of the Slovenian Academy of Sciences and Arts

Slovenian Academy of Sciences and Arts

Karst Research Institute

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Characteristics and impact of aged coal ash with slag emplaced in a karst cave: the case of Divaška jama, Slovenia

Scientific Reports (2021)

Andreea Oarga-Mulec Sara Skok Tatjana Simčić Janez Mulec

Abstract A mixture of coal bottom ash and slag, with a fraction of fly ash (CAFAS) from steam locomotives, was placed in the cave Divaška jama to delimit and level tourist trails. Emplacement began in 1914 and carried on for several decades. The CAFAS mixed with other cave material gradually changed its structure and appearance. Currently the concentration of some elements in the CAFAS (As, Cu, Hg, Ni, Pb, Zn), and also to a lesser extent in cave sediments (Cr, Cu, Ni), indicates a possibly harmful effect on sediment-associated biota based on ecotoxicological assays. Compared to the cave sediment, the CAFAS contains distinctly different mineral phases and presents a different source of radioactivity. Microbial metabolic activity of CAFAS is low, 0.22 μl O 2 /gDW h, but higher than that of cave sediment. The present environmental hazards from CAFAS are estimated to be low. Whereas the emplacement of CAFAS was seen initially a long-term solution for waste disposal and management of the cave, it turned out that CAFAS enriches the underground environment with inorganic and organic compounds and disperses pollution into the cave ecosystem. After its removal from the cave, the CAFAS should be investigated thoroughly due to its susceptibility to alteration.

Biota

10.1038/s41598-021-02842-7

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Citations (1)

A comparison of various bulking materials as a supporting matrix in composting blackwater solids from vacuum toilets

Journal of Environmental Management (2019)

Andreea Oarga-Mulec Jon Fredrik Hanssen Petter D. Jenssen Tjaša Griessler Bulc

Blackwater

Husk

Sawdust

Digitaria

Total dissolved solids

10.1016/j.jenvman.2019.05.005

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Citations (16)

Molecular Screening for Cyanobacteria and Their Cyanotoxin Potential in Diverse Habitats

Toxins (2024)

Maša Jablonska Tina Eleršek Polona Kogovšek Sara Skok Andreea Oarga-Mulec

Cyanobacteria are adaptable and dominant organisms that exist in many harsh and extreme environments due to their great ecological tolerance. They produce various secondary metabolites, including cyanotoxins. While cyanobacteria are well studied in surface waters and some aerial habitats, numerous other habitats and niches remain underexplored. We collected 61 samples of: (i) biofilms from springs, (ii) aerial microbial mats from buildings and subaerial mats from caves, and (iii) water from borehole wells, caves, alkaline, saline, sulphidic, thermal, and iron springs, rivers, seas, and melted cave ice from five countries (Croatia, Georgia, Italy, Serbia, and Slovenia). We used (q)PCR to detect cyanobacteria (phycocyanin intergenic spacer-PC-IGS and cyanobacteria-specific 16S rRNA gene) and cyanotoxin genes (microcystins-

Cyanotoxin

10.3390/toxins16080333

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Emerging Ecotone and Microbial Community of a Sulfidic Spring in the Reka River near Škocjanske Jame, Slovenia

Diversity (2021)

Janez Mulec Andreea Oarga-Mulec Sara Skok Stanka Šebela Rosana Cerkvenik

During long periods with no precipitation, a sulfidic spring (Smrdljivec) appears in the dry bed of the Reka River before sinking into the karst underground. The study characterizes the area’s geological setting, development of microbial communities and an ecotone, and impact on the vulnerable karst ecosystem. Geological mapping of the area, stable isotopic analyses, field measurements, and physico-chemical and toxicity analyses were applied to elucidate the environmental conditions. The spring’s microbial diversity was assessed using cultivation methods, microscopy, and metagenomics. Sulfur compounds in the spring probably originate from coal layers in the vicinity. Metagenomic analyses revealed 175 distinct operational taxonomic units in spring water and biofilms. Proteobacteria predominated in developed biofilms, and a “core” microbiome was represented by methylotrophs, including Methylobacter, Methylomonas, and Methylotenera. Diatoms represented an important component of biofilm biomass. A combination of environmental factors and climatic conditions allows the formation and accessibility of emerging biodiversity hotspots and ecotones. Details of their dynamic nature, global impact, and distribution should be highlighted further and given more protection.

Ecotone

Biogeochemical Cycle

10.3390/d13120655

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Citations (5)

Zero-discharge solution for blackwater treatment at remote tourist facilities

Journal of Cleaner Production (2017)

Andreea Oarga-Mulec Petter D. Jenssen Aleksandra Krivograd Klemenčić Matej Uršič Tjaša Griessler Bulc

Blackwater

Biofilter

Total dissolved solids

10.1016/j.jclepro.2017.08.002

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Citations (17)

ANew acanthocyclopsKiefer, 1927 (Copepoda: Cyclopidae) from Caves in Apuseni Mountains (North-Western Romania)

Annales Zoologici (2011)

Sanda Iepure Andreea Oarga-Mulec

A new stygobite species Acanthocyclops transylvanicus sp. nov. is described from the north-western Romanian Carpathians (Apuseni Mountains) and is accommodated in the subterranean kieferi-group. Acanthocyclops transylvanicus sp. nov. resembles closely A. biarticulatus Monchenko, 1972 in the segmentation pattern of the swimming legs (3.2/3.2/3.2/3.2), but differs by the following characters: antennary second endopodite segment with 7 setae; distal articles of endopodites of P1 and P3 with 4 and 5 setae, respectively; absence of coxopodite ornamentation pattern in leg 4; leg 4 endopodite with 3-segmented appearance, but lacking a functional articulation between the second and third segment. We assume that the 2-segmented nature of the leg 4 endopodite as observed in both species is a convergent acquisition. The adult shape of the leg 4 endopodite in A. transylvanicus sp. nov. results from the simple suppression of an arthrodial membrane formation. A. transylvanicus is the ninth representative known in Romania which is accommodated in the kieferi-growp. An identification key for the species of kieferi-growp known to occur in Romania is given.

Identification key

10.3161/000345411x584889

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Citations (7)

From Extracellular Vesicles to Global Environment: A Cosmopolite SARS-Cov-2 Virus<strong> </strong>

Veronika Kralj‐Iglič Raja Dahmane Tjaša Griessler Bulc Polonca Trebše Saba Battelino

Within the micro and nano world, tiny membrane-enclosed bits of material are more or less free to move and act as communication tools within cells, between cells, between different tissues and between organisms in global environment. Based on the mechanism of membrane budding and vesiculation that includes all types of cells, in this review, we attempted to present a review on SARS-CoV-2 virus actions in compartments of different scales (cells and their surroundings, tissues, organisms and society). Interactions of the virus with cells on a molecular level, with neural system, endothelium, hematopoietic system, gastrointestinal system and genitourinary system. Transmission route between organisms and between mother and fetus are considered. Also, transmission of virus through contact with materials and with environment, the suggested measures to prevent contamination with the virus and to support the organism against the disease are given.

Budding

10.20944/preprints202005.0518.v1

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Citations (2)

Characterization and fluorescence of yellow biofilms in karst caves, southwest Slovenia

International Journal of Speleology (2015)

Janez Mulec Andreea Oarga-Mulec Rok Tomazin Tadeja Matos

Biofilms of different colours that colonize surfaces within karst caves represent a source of nutrients. They occur commonly and abundantly at sites with sediments, and close to seepages or underground rivers. Golden-yellow subaerial biofilms are particularly well observed because of their contrast with their surroundings, the characteristics of the pigment and recently, even more, due to the characteristics of light-emitting diode (LED) illumination. Yellow microbial biofilms were sampled from three caves in southwestern Slovenia, Dimnice, Križna jama and Sveta jama. The highest concentration of cultivable microbes (2.33×108 CFU/g) and the biggest number of identified bacteria (66.0%) were retrieved from a sample from Sveta jama. Using MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight) for bacterial identification showed that different species of Pseudomonas prevailed in all samples. Yellow biofilms showed an absorption peak around 400 nm, and two emission peaks, a major in the blue (~460 nm) and a minor in the orange (~600 nm) parts of the spectrum when excited at 405 nm. Microbial mats that colonize surfaces are probably frequently overlooked in caves because they are difficult to observe when they have no pigmentation and the contrast with their surroundings is low. Additional studies are needed to aid the understanding of the role of pigmented biofilms and their interactions with underlying substrata in respect of the evolution of substrate micromorphology.

Subaerial

10.5038/1827-806x.44.2.1

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Citations (9)

Assessment of the physical environment of epigean invertebrates in a unique habitat: the case of a karst sulfidic spring, Slovenia

Ecohydrology (2014)

Janez Mulec Andreea Oarga-Mulec Edmund K. Schiller Aurel Perşoiu Ladislav Holko

Abstract A well‐fissured and faulted karst area at the Žveplenica sulfidic spring created suitable conditions for epigean copepods. Their presence in sulfidic water is a rare phenomenon. To understand the conditions related to sulfidic habitats in the region, two additional springs were analysed: the Studenec karst spring and the Sovra artesian borehole, which contains dissolved sulfide. Water temperature, chemistry and the stable isotopes of oxygen and hydrogen show that the Sovra borehole water has a different origin and history to that of the Žveplenica and Studenec springs water, which is derived from local precipitation. The low slope of the δ 18 O–δ 2 H regression line for the Žveplenica spring indicates a mixing of local precipitation water with geothermal sulfidic water that may explain the presence of live copepods. These harpacticoid and cyclopoid copepods must have survived anoxia and high sulfide for some time. The mean transit time for Žveplenica spring cannot be defined precisely from the available data, although the degree of attenuation of the isotopic signal indicates mean transit times of about 1·0 to 1·5 years. Sites similar to Žveplenica spring should be carefully analysed because not only do they provide insights into biodiversity but they also represent an ecotone between the anoxic/oxic and high/low sulfide of these karst waters. Copepods in similar geological settings can be used as additional parameters to evaluate conditions in subsurface sulfidic habitats and their spatial connectivity and responses to hydrological events. Copyright © 2014 John Wiley & Sons, Ltd.

Epigeal

10.1002/eco.1585

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Citations (11)

ATP luminescence assay as a bioburden estimator of biomass accumulation in caves

International Journal of Speleology (2016)

Janez Mulec Andreea Oarga-Mulec

A commercially available adenosine triphosphate (ATP) detection system (Hygiena, USA), supported by cultivable microbial indicators, was used to estimate bioburden in different habitats in and outside show caves: air, water and solid surfaces. A strong positive correlation between ATP concentration expressed as Relative Light Units (RLU) and Colony-Forming-Units (CFU) was observed for swab samples from cave surfaces. In terms of ATP units, surfaces in a single cave system (Postojna Cave) varied considerably (240-1,258,800 RLU/ 20 cm2) and commonly exceeded the bioburden level of analogues on the surface (0-114,390 RLU/ 20 cm2). Cave sub-habitats were colonized by physiologically distinct microbial communities in terms of their nutrient demands, temperature requirements and r/K growth strategy. The highest ATP biomass indicator (1,258,800 RLU/ 20 cm2) for the speleothem that had been touched but accompanied with comparable concentration of CFU (~106 CFU/ 20 cm2) for other cave sub-habitats, can be related to the presence of deposited human epithelium skin cells. Show cave infrastructures containing heavy metals, e.g. copper used in safety fences, reduce the viability of microbiota. Mass cave visitation and the presence of allochthonous organic matter result in high levels of airborne and total biomass. Once such material becomes airborne, the location of its settling depends upon natural and human-induced air movements. Underground habitats play an important role in the preservation and concentration of microbial biomass using air and water as transport mechanisms.

Speleothem

Bioburden

10.5038/1827-806x.45.3.1975

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Citations (11)