1. The response of microbes to anthropogenically induced perturbations in the Gulf of Trieste (northern Adriatic Sea) : dissertationNeža Orel, Tinkara Tinta, 2025, doktorska disertacija Opis: Marine ecosystems are constantly influenced by anthropogenic pressures, including inputs of nutrients, pollutants, and allochthonous microorganisms. These inputs can disrupt the dynamics of marine microbiomes, which encompass the majority of biomass and highest diversity of all life forms, controlling most biogeochemical cycles in the ocean realm. Despite their importance for public safety and potential influence on marine ecosystems functioning, knowledge of the impact of these perturbations on coastal microbiome dynamics remains in its infancy. The research objectives of this dissertation were to: (1) characterize the composition of the coastal microbiome in anthropogenically impacted coastal ecosystem; (2) investigate the genetic potential of selected microorganisms for pathogenicity and ecological adaptations; and (3) explore the effects of wastewater on the dynamics and functioning of the coastal microbiome, as well as its implications for the biogeochemical state of the ecosystem.
To address the first aim, we conducted a year-round in situ survey of the pelagic microbiome within anthropogenically impacted coastal ecosystem, focusing on the seasonal and spatial dynamics of traditional and alternative faecal bacterial indicators. We used a culture-independent approach combined with 16S rRNA amplicon sequencing, which overcome limitations of culture-based methods. This analysis revealed that the microbiome was primarily structured by seasonal changes, regardless of proximity to pollution sources. The statistical tool and oceanographic model we applied indicated that riverine water serves as a key vector for introducing allochthonous microbes. This study underscores the importance of molecular approaches combined with statistical and oceanographic modelling for advancing environmental health assessments and detecting microbial indicators.
To address the second aim, we applied whole-genome sequencing to assess the pathogenic potential and genomic features of selected Vibrio isolates. During the analysis, we identified cross-contamination in one isolate, which presented an opportunity to evaluate the effectiveness of bioinformatics workflows for contaminant removal and genome recovery. We reconstructed high-quality genomes of one Vibrio isolate from both axenic and contaminated cultures. Genomic analyses revealed that this isolate belongs to a sub-lineage of Vibrio campbellii associated with diseases in marine organisms. Moreover, this genome harboured a novel Vibrio plasmid linked to bacterial defense mechanisms and horizontal gene transfer, potentially offering a competitive advantage to this putative pathogen. This study highlights the utility of WGS and advanced bioinformatics in overcoming challenges posed by non-axenic cultures and provides new insights into the genomic characteristics of V. campbellii.
To address the third aim, we conducted a short-term microcosm experiment simulating wastewater discharge into coastal seawater, testing two types of wastewaters: (a) unfiltered, containing nutrients, pollutants, and allochthonous microbes, and (b) pre-filtered, retaining only nutrients and pollutants. Our results showed that wastewater, significantly increased nutrient levels (dissolved organic carbon, ammonium, orthophosphate). Using a multi-omics approach with measurements of microbial metabolic activity, we found that nutrient enrichment significantly influenced bacterial metabolism. This was evidenced by enriched protein profiles and increased leucine aminopeptidase and olease activity, indicating bacterial degradation of complex proteins and lipids. At the same time, the phosphate input resulted in a decreased alkaline phosphatase activity, with important implications for phosphorus cycling. Overall, wastewater primarily induced functional shifts in coastal microbiomes, highlighting the resilience and functional redundancy of coastal microbial communities and hence the biogeochemical processes they operate.
Ključne besede: coastal microbiome, anthropogenic impact, wastewater pollution, bacterial community dynamics, allochthonous microorganisms, potential pathogens, Vibrio campbellii, multi-omics, whole-genome assembly, dissertations
Objavljeno v RUNG: 16.04.2025; Ogledov: 143; Prenosov: 0
 Celotno besedilo (10,24 MB) |
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3. Disinfection of wastewater using porous Fe2O3 thin film : master's thesisRanin M. D. Ismail, 2024, magistrsko delo Opis: The contamination of water bodies by microorganisms is seen as a highly significant issue that poses a threat to human and animal well-being. The primary objective of this master thesis is to develop and evaluate an environmentally friendly photoelectrochemical (PEC) method using porous Fe₂O₃ thin films for the disinfection of wastewater. This thesis presents the novel application of porous Fe₂O₃ thin films, which were produced using a cost-effective spin-coating technique, to improve the process of PEC disinfection. The PEC approach has been demonstrated to be highly effective in disinfection of wastewaters deliberately contaminated with E. coli bacteria. The crystallinity of the Fe₂O₃ porous thin films was confirmed using X-ray diffraction (XRD), while the film morphology was studied using scanning electron microscopy (SEM). The PEC disinfection procedures were conducted in the presence of two separate electrolytes, sodium sulfite (Na₂SO₃) and sodium chloride (NaCl), which were chosen for their specific roles in improving the effectiveness of disinfection. The PEC method shown efficacy in inactivating E. coli, with 45% of the bacteria being inactivated in the presence of 2 mM Na₂SO₃ and complete inactivation achieved with 20 mM NaCl. The findings suggest that the PEC disinfection process is a highly efficient and eco-friendly technology that can be used as a practical substitute for traditional disinfection methods. As a result, it has potential applications in ensuring public safety and safeguarding the environment, particularly in relation to wastewater treatment.
Ključne besede: Treated wastewater, Disinfection, Escherichia coli, Photoelectrochemical oxidation, Fe2O3 thin films, Sodium sulfite and Sodium chloride.
Objavljeno v RUNG: 09.09.2024; Ogledov: 1627; Prenosov: 19
Celotno besedilo (2,23 MB) |
4. SnO2-Containing Clinoptilolite as a Composite Photocatalyst for Dyes Removal fromWastewater under Solar LightAndraž Šuligoj, Jelena Pavlovič, Iztok Arčon, Nevenka Rajić, Nataša Novak Tušar, 2020, izvirni znanstveni članek Opis: Due to their adsorbent, ion exchange and catalytic properties zeolites are suitable for a variety of applications. We report on the photocatalytic activity of a readily available and inexpensive natural zeolite clinoptilolite (Z) containing SnO2 (Sn-Z). The Sn-Z samples with 3–15 wt. % of Sn were prepared by using a precipitation–deposition method. Powder X-ray diffraction analysis showed that the zeolite structure was unaffected by the introduction of the Sn-phase. Diffuse reflectance UV/VIS spectra of the Sn-Z samples confirmed the presence of SnO2 and X-Ray absorption spectroscopy analyses suggested that the SnO2 particles mainly resided on the surface of the clinoptilolite, while ATR-FTIR analysis gave some clues that part of the SnO2 phase was incorporated in the pores of the zeolite. The presence of SnO2 in Sn-Z increased both adsorption capacity and photocatalytic performance which could be partially explained by higher surface area and partially with an increased negative potential of the surface. Adsorption and total degradation of methylene blue (MB) for the Sn-Z with the highest amount of Sn (15 wt.%) was about 30% and 45%, respectively, suggesting a synergetic effect between SnO2 and the clinoptilolite lattice. Reusability tests showed that these catalysts present a promising material for water purification.
Ključne besede: SnO2, zeolite, SnO2-clinoptilolite composite, photocatalysis, solar light, methylene blue
removal, wastewater treatment
Objavljeno v RUNG: 25.02.2020; Ogledov: 4541; Prenosov: 135
Celotno besedilo (3,50 MB) |
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6. Biogas production from brewery yeast in an EGSB reactorGregor Drago Zupančič, Milenko Roš, Miran Klemenčič, Matej Oset, Romana Marinšek-Logar, 2016, strokovni članek Opis: Experience over a five-year period of full throughput using anaerobic co-digestion of brewery yeast for biogas production is described in this contribution. The brewery, with a total amount of available yeast (0.7 v/v %), had a 26.2 % increase in COD load and a 38.5 % increase in biogas production resulting in an increase in the biomethane/natural gas substitution ratio in the brewery from 10 % to 16 %.
Ključne besede: Anaerobic digestion, biogas production, brewery yeast, brewery wastewater, EGSB
Objavljeno v RUNG: 21.04.2016; Ogledov: 8029; Prenosov: 0
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