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Impact of untreated wastewaters on the microbiological water quality of the Danube River and its tributaries in Serbia
No full textPollution of surface waters still represents one of the major environmental challenges in the Republic of Serbia, where wastewaters are discharged directly into the recipients without proper treatment. Within the last decade, we have assessed the microbiological water quality of more than 100 sites situated at different water bodies in Serbia. Quality was determined using faecal indicator bacteria, while microbial source tracking was employed to assess the source of pollution. Almost 50 % of the investigated sites were characterized by critical or even higher level of faecal contamination indicating that untreated wastewaters indeed represent significant pollution pressure on surface waters. Human-associated markers were prevalent in samples from the majority of contaminated sites but the source of pollution was not exclusively human-associated. The impact on the water quality of the Danube River was demonstrated in our previous research conducted at the whole river level within the Joint Danube Surveys. In the river stretch from Novi Sad to its confluence with the Velika Morava River, all the midstream samples were critically polluted. In this section, the highest level of pollution was recorded downstream of Belgrade. As ultimate recipients of wastewaters, Danube and its largest tributary Sava currently represent the only solution for disposing of wastewaters originating from the Serbian capital‘s 1,700,000 inhabitants. Such kind of disposal rises additional issues such as antimicrobial resistance and presence of infectious agents in water. For instance during COVID-19 pandemic, we have demonstrated that SARS-CoV-2 RNA can be detected even in surface waters of the Danube River at the sites receiving high wastewater loads from Belgrade which was the unique case for the Basin. Despites its extreme importance in this case, wastewater-based epidemiology is neglected in our country and hereby we would like to emphasize the need for implementation of program of such kind in Serbia
Isolates of Pinus sp. in liposomes: influence of the carrier on antimicrobial activity against Cutibacterium acnes
No full textIn an attempt to develop a product based on natural ingredients for potential local treatment of
acne-prone skin, the purpose of this study was to examine antimicrobial act ivity against
Cutibacterium acnes of the Pinus sp. green cones' isolates (essential oil, EO and the extract, E)
incorporated into liposomal dispersions.
EO was isolated from the crushed plant material by steam distillation using a Clevenger apparatus,
while E was obtained via Soxhlet apparatus using 70% (VN) ethanol. Four liposomal dispersions were prepared using purified water and Phosal 40 IP (Lipoid, Germany): blank dispersion (sample L), dispersion with encapsulated EO (sample L-EO), blank dispersion with the addition of E in the outer phase (sample L-E) and with encapsulated EO (sample LEO-E). Zetasizer Lab Blue Label was used for liposome size and zeta potential evaluation, while measurements of pH and electrical conductivity were performed using pH-meter HI 9321 and conductometer CDM 230, respectively. In order to check the preliminary physico-cbemical stability of the prepared samples, measurements of Ph, electrical conductivity, liposome size, and zeta potential were re-evaluated after 30 and 90 days of room temperature storage. The antibacterial effect of the examined EO, E, and liposomal dispersions was tested by agar well diffusion assay on the standard strain C. acnes ATCC 6919, while minocycline was used as a positive control. Thereby, EO and E were tested in the same concentrations used in the liposomal dispersions.
The droplet size of the prepared liposomes was in the range of 197.4 to 250 nm. The average
droplet size in the sample L was 217.0. The addition of EO led to a decrease in droplet size,
while the addition of E had an inverse effect. In all samples, the polydispersity index, as a
measure of droplet size distribution uniformity was lower than 0.2 indicating that the
liposomes were relatively monodisperse. The zeta potential of tested liposomes ranged from -36.63 to -41.16 mV, suggesting good kinetic stability. pH from 4.0 to 5.01 in all tested samples
indicated their applicabil ity in skin products. The addition of EO led to the decrease of
conductivity compared to the sample L, while the addition of E led to its increase. Repeated
measurements of tested physicochemical characteristics of the investigated liposomes did not change applicability, suggesting satisfactory preliminary stability. Neither of the tested Pinus sp.
isolates nor liposomal samples L, L-EO , and L-E exhibited antimicrobial activity against C.
acnes. However, encapsulation of EO into liposomes along with theaddition of E in the outer phase of the dispersion resulted in inhibition zones measuring 11.47±0.51 and 12.26±0.98 mm (for undiluted and liposomes diluted with brain heart infusion (BHI) in a ratio of 1:2,
respectively) suggesting that both encapsulation of EO into liposomes and synergism between tested isolates (EO and E) enhanced biological activity related to the potential application of the
prepared sample on the skin. It should be emphasized that minocycline yielded inhibition zones of
20.10 ± 4.24 and 18.28±3.60 mm used in the concentration of 8 and 4 µg/m, respectively.
In conclusion, in the present study, liposomes with EO and E isolated from green cones of Pinus sp. revealed satisfactory physico-chemical characteristics/stability, suggesting their prospective
usage in the preparation of the products based on natural ingredients for potential local treatment
of acne-prone skin
Application of Caged Sparus aurata in Biomonitoring of the Boka Kotorska Bay (Montenegro)
No full textIn this study early signs of deterioration of the ecosystem in the Boka Kotorska Bay were assessed by applying an active biomonitoring approach for the first time in coastal area of Montenegro. Gilthead sea bream (Sparus aurata), commercially farmed in the Bay, was used as a bioindicator. Specimens were translocated from an aquaculture farm to more impacted sites within the Bay. After two weeks of exposure, the level of DNA damage was assessed in blood cells by comet assay and micronucleus test while muscle tissues were prepared for trace element determination. The results confirmed that an active biomonitoring approach is a valuable tool for eco/geno-toxicological assessment in the marine environment. Comet assay was sensitive in discrimination of the studied groups, moreover it was sensitive enough to detect stress related to the caging procedure and translocation of animals. Lack of feeding during the exposure period was reflected on the condition index. Based on the Integrated Biomarker Response (IBR), the group exposed at the main port - Porto Montenegro was shown to be under higher environmental stress than groups exposed at reference site Dobrota (IBM) and fish farm CogiMAR. An increase in the frequency of micronuclei was evident only at this site (Porto Montenegro). Obtained trace element concentrations in fish tissues were significantly lower in comparison to values recommended by the national legislative
Intracelular localization of manganese as a part of Mn-O-Ca cluster in the microalga Chlorella sorokiniana
No full textWe have previously demonstrated using EXAFS and XANES techniques that the unicellular
green microalga Chlorella sorokiniana has the ability to form multivalent Mn-O-Ca clusters in the
presence of excess manganese (Mn) ions. These clusters resemble the structure of the tetramanganese-calcium core of the oxygen-evolving complex of photosystem II, with Mn ions in various oxidation states (+3, +4). In this study, the NanoXFM method was employed to analyze the elemental mapping and structure of Mn coordination within the cells of microalga C. sorokiniana
after the treatment with high but sublethal dose of Mn. The main finding was the strong elevation
of Mn signal after the treatment within punctuate formations, partially overlapped with calcium,
potassium and phosphorus distribution. These structures resemble by size and shape acidocalcisomes, acidic organelles with the function of heavy metals accumulation. This finding is similar to the case of nickel excess and sequestration of heavy metals appears to be a common adaptive response/defence mechanism of C. sorokiniana cell
The impact of microplastics on insect biodiversity in the alluviums of the three largest river basins in Serbia
No full textThe pollution with plastics has been recorded in all parts of the biosphere including aquatic and terrestrial ecosystems. Plastic particles smaller than 5 mm and larger than 100 nm are recognized as most dangerous to ecosystems and are called microplatics (MP). There are numerous studies that have shown the presence of MP in surface waters, primarily in river ecosystems. Despite the fact that rivers have a great ability to self-purify, microplastic particles remain in the river basin, contaminating the floodplain where they remain for a long period of time, including the process of matter circulation in nature. The presence of MP in the soil among all makes changes in the biodiversity of insects and other soil organisms. The one of the first researches on the presence of MP in soils in Serbia is currently being carried out as part of the project EMIPLAST - SoS. This research aimed to access the impact of MP on soilʹs main chemical, physical and biological properties by comparing polluted and non-polluted forest sites and agricultural soils, used for cultivation in the three largest alluvial plains in Serbia – Danube, Sava and Morava. After a series of samplings done by standard Pitfall traps, the dominance of insect species from Carabidae family was significant. The presence of other different species such as Milipedes, Spiders and Flies was also recorded. Their numbers depended on the degree of contamination (polluted and unpolluted) of the soil with microplastics
Non-toxic orange carbon dots stimulate photosynthesis and CO2 assimilation in hydroponically cultivated green beans (Phaseolus vulgaris)
No full textContinuous increasing leaf photosynthesis may enhance plant yield. As an evolutionary property,
plants use less photosynthetic capacity than is theoretically possible. Plant nanobionics is a bioengineering field that improves plant functions using nanoparticles. We applied orange carbon
dots (o-CDs) onto the foliage of green beans (Phaseolus vulgaris) grown in hydroponics to improve
their photosynthetic performance and CO2 assimilation. Photosynthesis parameters, photosynthetic pigments content, total phenolic content (TPC) and antioxidative activity (TAA) were measured. Results show that photosynthetic pigments remained unchanged, while photosynthesis was improved. Both o-CDs concentrations decreased TPC and TAA. The light response curve showed higher CO2 assimilation at both o-CDs concentrations, particularly at lower light intensity.
Correlation analysis confirmed increased CO2 binding and assimilation at 1 mg L−1. This study
demonstrated the potential of using o-CDs as a safe biostimulator through photosynthesis increase
and CO2 assimilation without toxic effects on plants. This may stimulate yield increase that paves the way for their agricultural application
Преглед угрожених врста риба у фауни Србије - Oxynoemacheilus bureschi (струмичка бркица)
No full textNa globalnom nivou, strumička brkica ne smatra se ugroženom
vrstom (Crivelli, 2006c). U Srbiji ima status ugrožene vrste (EN),
kako zbog malog obima rasprostranjenja (EOO iznosi 241,5 km2),
tako i zbog male površine naseljavanja (AOO iznosi 8 km2). Osim
toga, ustanovljen je i mali broj lokaliteta na kojima se vrsta javlja
(≤5), kontinuirano smanjivanje obima rasprostranjenja i površine
naseljavanja, kao i opadanje kvaliteta staništa – kriterijumi B1ab(
i,ii,iii)+2ab(i,ii,iii)
HAEMOSPORIDIAN PARASITES IN WINTERING LONG-EARED OWLS ASIO OTUSIN NORTHERN SERBIA
No full textThe study of endoparasites in wildlife is critical to understanding their impact on animal health and population dynamics. Research on parasites belonging to the phylum Apicomplexa has mainly focused on passerines, leaving other bird groups, such as owls, less studied. Long-eared owl is a regular breeder in northern Serbia. During the fall-winter period, it gathers in large communal roosts consisting mainly of resident individuals. Considering that there are only a few studies on haemosporidian infections in Long-eared Owls and that only four haemosporidian species have been identified so far, we investigate the prevalence, parasitemia and diversity of avian haemosporidian infections in these birds. In our study, 103 long-eared owls from wintering grounds in northern Serbia (Vojvodina) were examined for haemosporidian blood parasites during fall-winter 2023/24. All three genera were found, with Leucocytozoon being the most abundant. At the same time, we identified four co-infections, more often combined with Leucocytozoon and Plasmodium. The overall prevalence was 46.8%, while the mean parasitemia was low, only 0.15%. The presence of parasites did not affect the Scaled Mass Index (SMI) and the health status of the individuals analyzed. Furthermore, no significant difference was found between the infection status of males and females, nor between different age groups
Acipenser nudiventris
No full textNa globalnom nivou, sim se smatra kritično ugroženom vrstom (CR) prema kriterijumima A2cde. Na osnovu procene brojnosti populacije na teritoriji Srbije, simu je dodeljen status kritično ugrožene vrste (CR), prema kriterijumu C2a(i,ii)b. Uočeno je kontinuirano opadanje brojnosti sa ekstremnim fluktuacijama u broju odraslih jedinki, pri čemu je procenjeno da je njihov maksimalni broj u svakoj populaciji manji od 50, dok je ukupan broj zrelih jedinki između 50 i 250. Veličina prostora na kome se vrsta pojavljuje (EOO) u Srbiji iznosi 14.239 km², dok je površina naseljavanja (AOO) svega 36 km². Osim toga, ustanovljeni su i značajno fragmentisan areal i mali broj lokaliteta na kojima je vrsta pronađena.
Sim nastanjuje slivove Crnog, Azovskog, Kaspijskog i Aralskog mora. Formira anadromne i rezidentne populacije, a u Dunavu je prisutan samo rezidentni tip. Pre izgradnje hidroelektrane "Đerdap I" jedinke ove vrste su migrirale sve do Komarna i Bratislave. U Srbiji postoje zabeleženi nalazi u Dunavu na području Apatina, Beograda i Đerdapske klisure. Smatra se da povremeno zalaze i u Savu, Dravu i Tisu.At the global level, the ship sturgeon (sim) is considered Critically Endangered (CR) according to criteria A2cde. Based on the population size assessment in Serbia, the species has been assigned the status of Critically Endangered (CR) under criterion C2a(i,ii)b. A continuous decline in population size has been observed, with extreme fluctuations in the number of adult individuals. It is estimated that the maximum number of mature individuals in each population is fewer than 50, while the total number of mature individuals is between 50 and 250. The extent of occurrence (EOO) in Serbia is 14,239 km², while the area of occupancy (AOO) is only 36 km². In addition, the species’ range is significantly fragmented, and the number of known locations where it occurs is very limited.
The ship sturgeon inhabits the basins of the Black, Azov, Caspian, and Aral Seas. It forms both anadromous and resident populations, and only the resident type is present in the Danube. Before the construction of the "Đerdap I" hydropower plant, individuals of this species migrated as far upstream as Komárno and Bratislava. In Serbia, it has been recorded in the Danube near Apatin, Belgrade, and the Iron Gates Gorge. It is also believed to occasionally enter the Sava, Drava, and Tisza rivers
ATLANTIC STURGEON Acipenser sturio Linnaeus, 1758
No full textTelo je izduženo i vretenasto, pokriveno sa pet uzdužnih nizova ploča (leđni, dva bočna i dva trbušna) (Slika 53). Prva leđna ploča srasla je sa glavom i nalazi se ispred nivoa oka. Odnos visine i širine ploča bočnog niza manji je od 2:1. Između leđnog i bočnih nizova nalaze se sitne rombične pločice. Leđa su maslinasto-plava, zelenkasto-smeđa do crnkasta sa zlatnim tačkama, bokovi svetliji sa srebrnim tačkama, dok je trbuh beo. Rostrum je šiljat, uzak i umerene dužine, a donja sna prekinuta u sredini. Usta su donja, a brkovi bez resa i na pola rastojanja od vrha rostruma do prednje ivice gornje usne ili bliže ustima. Leđno peraje smešteno je daleko pozadi, grudna peraja su sa snažnim bodljama, dok je repno peraje heterocerkno. Leđnih ploča ima 9–16, bočnih 24–39 i rbušnih 9–14. Peraja: D 30–44; A 23–30. Branhiospina u prvom škržnom luku ima 18–25 (Bauchot, 1987). Najveća zabeležena dužina iznosi 6 m, a masa tela 1.000 kg (Kottelat & Freyhof, 2007). Danas retko prelazi 2 m (Bauchot, 1987). Maksimalna zabeležena dužina života je 100 godina (Muus & Dahlström, 1968).The body is elongated and spindle-shaped, covered with five longitudinal
rows of scutes (dorsal, two lateral and two ventral) (Figure 53).
The first dorsal scute is fused with head and is located anterior to the
eye level. The ratio of height to width of the scutes of the lateral rows is
less than 2:1. There are small rhombic plates between the dorsal and lateral
rows. The dorsum is olivaceous blue, greenish brown to black with
golden spots, the flanks are lighter with silver spots, while the belly is
white. The rostrum is pointed, narrow and of medium length, the lower
lip is interrupted at centre. The mouth is inferior, barbels not fimbriate
and lie midway between the tip of the rostrum and the anterior edge of
the upper lip or closer to the mouth. The dorsal fin is located far back,
the pectoral fins have strong spines, while the caudal fin is heterocercal.
There are 9–16 dorsal, 24–39 lateral and 9–14 ventral scutes. Fins: D 30–
44; A 23–30. There are 18–25 gill rakers on the first gill arch (Bauchot,
1987). The greatest recorded length is 6 m and the body mass is 1,000 kg
(Kottelat & Freyhof, 2007). Today, it rarely exceeds 2 m (Bauchot, 1987).
The maximum life expectancy is 100 years (Muus & Dahlstroem, 1968)