ISSN 2738-0971 | eISSN 2738-1013
Bulletin of Natural Sciences Research
Open access journal | Double-blind peer review

Predrag Vasić

Faculty of Sciences and Mathematics, University of Priština in Kosovska Mitrovica, Kosovska Mitrovica, Serbia

Articles

Open Access Original Scientific Paper

RECORDS OF LICHEN SPECIES FROM GENUS ACAROSPORA, NEW FOR SERBIA, SOUTHWEST BALKAN PENINSULA

by Gordana Aleksić, Predrag Vasić, Tatjana Jakšić

The lichens: Acarospora impressula, A. nitrophila, A. nodulosa, A. schleicheri, A. sinopica, A. smaragdula and A. umbillicata, collected in North Kosovo are reported as a new species to Serbia, following a recent lichenological survey. Location, herbarium deposits and substrates are given, together with notes on distribution of the reported taxa.

View Full-Text DOI 10.5937/bnsr13-42787 Published: 09 Jun 2023
Open Access Original Scientific Paper

DIATOM SPECIES COMPOSITION AND THEIR SEASONAL DYNAMICS IN THE TIMOK RIVER BASIN

by Nikola Đukic, Tatjana Jakšić, Olivera Papović, Predrag Vasić

The aim of this paper was to present the composition and seasonal dynamics of epilthic diatoms in the Timok River basin. The diatom samples were collected along the Timok River basin in March, May, August and November 2017. Permanent diatom slides were prepared after oxidizing the organic material by the hydrogen peroxide (H2O2). The cleaned diatom materials were mounted on permanent slides using ZRAX glue. A total of 85 taxa were identified in the Timok River Basin. The benthic diatom taxa belong to 31 genera with the highest diversity observed within Navicula Bory (15), Nitzschia Hassall (12) and Gomphonema Ehrenberg (8). Quantitative analysis showed that in all seasons, Achnanthidium minutissimum and Amphora pediculus were dominant taxa. In May, they were joined by the Achnanthidium pyrenaicum, Gomphonema olivaceum and Ulnaria ulna; in August by the Cocconeis placentula, Denticula kuetzingii, Melosira varians, Navicula metareichardtiana, Nitzschia capitellata, N. fonticola and N. palea; in November by the D. kuetzingii, G. olivaceum, G. pumilum, N. metareichardtiana, N. veneta, Nitzschia capitellata and N. palea and in March by A. pyrenaicum, Diatoma moniliformis, G. olivaceum, N. palea and U. ulna. Our research is the floristical and ecological study of benthic diatoms in this basin and can form the groundwork for further research work.

View Full-Text DOI 10.5937/bnsr11-25709 Published: 14 Dec 2021
Open Access Original Scientific Paper

IMPACT OF PB, NI AND CD ON THE GERMINATION OF BARLEY SEEDS, VARIETY JADRAN

by Predrag Vasić, Tatjana Jakšić, Gorica Đelić

The aim of this study was to determine the effect of lead, nickel and cadmium on the germination of barley seeds (Hordeum vulgare L.) of Jadran variety. Based on the percentage of germination, germination energy, and root and hypocotyl length, authors done an analysis of the effects of PbCl2, NiCl2, CdCl2 solutions, in concentrations of 103 mol/m3, 102 mol/m3, 10 mol/m3, 1 mol/m3, 10 -1 mol/m3, 10-2 mol/m3. The results showed that germination and germgrowthin stress conditions which are caused by heavy metals depend on the type of metal and its concentrations. The most toxic effect of alltested solutions had CdCl2, and the weakest toxic effect had PbCl2.

View Full-Text DOI 10.5937/bnsr10-23916 Published: 08 Jul 2020
Open Access Original Scientific Paper

EFFECT OF DETERGENTS ON ALKALINE INVERTASE AND ALKALINE PHOSPHATASE ACTIVITY OF FUNGI MUCOR PLUMBEUS Bonord, 1864, ASPERGILLUS NIGER Tiegh, 1867 AND TRICHODERMA HARZIANUM Rifai, 1969

by Ivana Matović-Purić, Tatjana Jakšić, Tatjana Mihajilov-Krstev, Predrag Vasić

Due to their diverse metabolic potential, many filamentous fungi have a great ability for degradation of different waste substances. The present research was aimed to investigate ability of fungi Mucor plumbeus, Aspergillus niger and Trichoderma harzianum, isolated from sewer and industrial waste water, to conduct degradation of high concentrations of commercial detergent (0.3%). Within enzyme extracts of samples taken during period of 3–16 days, activity of alkaline invertase and alkaline phosphatase was followe spectrophotometrically at room temperature. Obtained results proved that all examined fungi affected degradation of detergent. Quality (inhibition/stimulation) and quantity of action of detergent on activity of investigated enzymes depended on fungal species and incubation period. The highest inhibiting effect of detergent was recorded on 9th day of incubation in samples of T. harzianum and A. niger, while its most obvious stimulating effect was noticed on 3rd day of incubation in samples of T. harzianum and M. plumbeus. Investigated fungi can be used for purification of waste water containing high concentrations of detergent.

View Full-Text DOI 10.5937/univtho10-21042 Published: 29 Jan 2020
Open Access Original Scientific Paper

THE EFFECT OF ALTITUTDE ON THE PRESENCE OF PLANT SPECIES IN STANDS FOR JUNIPERUS L. PLANT SPECIES ON KOPAONIK

by Predrag Vasić, Tatjana Jakšić, Nikola Đukic

In this paper we present an assessment of the altitude effect on the plant species presence in different plant communities – the species of Juniperus genus (Juniperus communis L., Juniperus oxycedrus L. and Juniperus sibirica Burgsdorf) on Kopaonik Mountain. Two juniper species (Juniperus communis and Juniperus oxycedrus) were recorded at altitudes ranging from 420 m to 1420 m, while the third species Juniperus sibirica was found at an altitude of 2100 m. It was determined that the plant communities with the presence of species of the Juniperus genus differ in botanical terms at different altitudes. It was found that there are plant species in certain communities that are present only at some altitudes, while others were present at almost all altitudes. The species of Hypericum perforatum L. is recorded in all of plant communities surveyed that proves its best adaptation to the conditions at different altitudes.

View Full-Text DOI 10.5937/univtho6-12389 Published: 30 Dec 2016