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33. Determination of biogenic amines formation by autochthonous lactic acid bacteria from ‘Refošk’ grapes using different analytical methodsJelena Topić, Lorena Butinar, Martina Bergant Marušič, Dorota Korte, Branka Mozetič Vodopivec, 2022, original scientific article Abstract: Different analytical methods were tested and optimized for the determination of four biogenic amines (BA) histamine, putrescine, cadaverine and tyramine produced by grape-associated lactic acid bacteria (LAB). Autochthonous LAB were isolated from ‘Refošk’ grapes belonging to Slovenian-Italian Karst region as they represent a potential pool of beneficial LAB starter bacteria for improving the typicality and quality of wine. Six isolated strains were screened by multiplex PCR, of which four strains were positive for BA-forming genes (MKBT-49, MKBT-282, MKBT-568, MKBT-570). The production of BA was evaluated by thin-layer chromatography (TLC), high-performance liquid chromatography coupled to diode array detection (HPLC-DAD) and enzymatic method. The HPLC-DAD results showed that strain MKBT-49 (tyrdc+) had high tyramine production (386.6 ± 0.14 mg/L), which was confirmed by TLC. The ability to produce putrescine was confirmed in strain MKBT-282 by PCR, HPLC-DAD (16.4 ± 1.72 mg/L), and TLC. Histamine-producing ability was detected in strain MKBT-570, with a concentration below the limit of detection of the HPLC-DAD (<0.2 mg/L), while the other two methods were not sensitive enough for confirmation. This study shows that the production of BA can detected in native LAB and that relatively simple method such as TLC can be used effectively for the initial screening.
Keywords: grapes, wine-like matrices, biogenic amines, autochthonous lactic acid bacteria, analytical methods
Published in RUNG: 03.01.2022; Views: 1712; Downloads: 7
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34. In vitro toxicity of arsenic rich waters from an abandoned gold mine in northeast PortugalMaria do Rosário Costa, Doroteja Gošar, Marika Pinti, Adelaide Ferreira, Martina Bergant Marušič, 2021, original scientific article Keywords: arsenic, water contamination, cytotoxicity, genotoxicity, Caco-2 cells
Published in RUNG: 23.07.2021; Views: 1954; Downloads: 10
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36. Spremljanje, ugotavljanje in zagotavljanje kakovosti: poročilo za študijsko leto 2019/2020 : Univerza v Novi Gorici. : poročilo za študijsko leto 2019/2020 : Univerza v Novi Gorici.Iztok Arčon, Jana Beguš, Blaž Belec, Martina Bergant Marušič, Lorena Butinar, IMRE CIKAJLO, Saša Dobričič, Sandra Gardonio, Renata Kop, Martin Knez, Boštjan Potokar, Branka Mozetič Vodopivec, Egon Pavlica, Samo Stanič, Tea Stibilj Nemec, Željko Oset, VERONIA Piccinini, Peter Purg, Arthur Stepanov, Aljaž Rener, Nives Štefančič, Ana Toroš, Tanja Urbančič, Vanesa Valentinčič, NIKA VODOPIVEC, treatise, preliminary study, study Keywords: samoevalvacijsko poročilo
Published in RUNG: 23.12.2020; Views: 3371; Downloads: 0
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37. Performance of microAethalometers: Real-world Field Intercomparisons from Multiple Mobile Measurement Campaigns in Different Atmospheric EnvironmentsHoney Alas, Thomas Mueller, Kay Weinhold, Sascha Pfeifer, Kristina Glojek, Asta Gregorič, Griša Močnik, Luka Drinovec, Francesca Costabile, Martina Ristorini, A. Wiedensohler, 2020, original scientific article Abstract: Small aethalometers are frequently used to measure equivalent black carbon (eBC) mass concentrations in the context of personal exposure and air pollution mapping through mobile measurements (MM). The most widely used is the microAethalometer (AE51). Its performance in the laboratory and field is well documented, however, there is not sufficient data in the context of its performance in different environments. In this investigation, we present the characterization of the performance of the AE51 through field unit-to-unit intercomparisons (IC), and against a reference absorption photometer from three MM campaigns conducted in drastically different environments. Five IC parameters were considered: i) study area, ii) location of IC, iii) time of day, iv) duration of IC, and v) correction for the filter-loading effect. We can conclude that it is crucial where and how long the IC have been performed in terms of the correlation between the mobile and reference instruments. Better correlations (R2 > 0.8, slope = 0.8) are achieved for IC performed in rural, and background areas for more than 10 minutes. In locations with more homogenous atmosphere, the correction of the loading effect improved the correlation between the mobile and reference instruments. In addition, a newer microAethalometer model (MA200) was characterized in the field under extreme cold conditions and correlated against another MA200 (R2 > 0.8, slope ≈ 1.0), AE51(R2 > 0.9, slope ≈ 0.9), and a stationary Aethalometer (AE33) across all wavelengths (R2 > 0.8, slope ≈ 0.7). For MA200, the loading effect was more pronounced, especially at the lower wavelengths, hence the correction of the loading effect is essential to improve the correlation against the AE33. The MA200 and AE51 proved to be robust and dependable portable instruments for MM applications. Real-world quality assurance of these instruments should be performed through field IC against reference instruments with longer durations in areas of slowly changing eBC concentration.
Keywords: Portable instruments, Mobile monitoring, Black carbon, Instrument intercomparisons
Published in RUNG: 15.09.2020; Views: 2661; Downloads: 184
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38. Determination of biogenic amine-forming potential of naturally occuring lactic acid bacteria (LAB) strains isolated from the grapes of Vitis vinifera cv. Refošk grape varietyJelena Topić, Lorena Butinar, Martina Bergant Marušič, Dorota Korte, Branka Mozetič Vodopivec, 2020, published scientific conference contribution abstract Abstract: Biogenic amines are naturally occurring compounds that have been reported in variety of food, such as fish, meat, cheese, vegetables, and wines. When biogenic amines are formed by microorganisms such as lactic acid bacteria (LAB) they may have adverse effect on human health. The most common biogenic amines found in foodstuff are histamine, tyramine, putrescine and cadaverine. LAB are used as starters in the production of several foods and beverages. In wines they are used in malolactic fermentation, where the conversion of malic acid to lactic acid occurs. The aim of this work was to determine biogenic amine-forming capacity of indigenous LAB strains isolated from grapes which were PCR positive and screening medium positive for biogenic amines. Three methods for the confirmation of LAB biogenic amine-forming potential were developed and compared: HPLC-DAD and TLC methods both using derivatization agent dansyl chloride and enzymatic method using horseradish peroxidase (HRP) and diamine oxidase (DAO) enzymes. The applicability of methods was tested on the three known biogenic amine-producing LAB strains: 0006, 9809, 9906 (IOEB, France). The limit of detection (LOD) of the methods was <1 mg/L for HPLC-DAD, 5 mg/L for TLC and 25 mg/L for enzymatic method. Although the LODs between the proposed methods differed, all of the three methods confirmed BA-forming potential of the three strains. Furthermore, the proposed methods were applied for the analysis of three indigenous strains: MKBT-282 (BA+), MKBT-307 (BA-) and MKBT-325 (BA+). The positive or negative BA-forming potential was confirmed with all of the three proposed methods.
Keywords: lactic acid bacteria, biogenic amines, histamine, grape
Published in RUNG: 10.07.2020; Views: 3004; Downloads: 0
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39. The AMIGA underground muon detector of the Pierre Auger Observatory - performance and event reconstructionAna Martina Botti, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: Pierre Auger Observatory, muon detector, event reconstruction
Published in RUNG: 16.06.2020; Views: 2796; Downloads: 78
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40. Test benches for the upgrade of the Pierre AugerObservatory electronicsMartina Boháčová, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, published scientific conference contribution Keywords: Pierre Auger Observatory, surface detector station, electronics, test benches
Published in RUNG: 16.06.2020; Views: 2543; Downloads: 77
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