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Effects of mining activities and municipal wastewaters on element accumulation and integrated biomarker responses of the European chub (Squalius cephalus)
No full textThis study aimed to determine concentrations of 29 elements in the gills and liver as well as biomarker response in gills, liver, and blood of European chub from Pek River (exposed to long-term mining activities), and to compare these findings with individuals from Ibar River (influenced by emission of treated municipal wastewater) and Kruščica reservoir (source of drinking water) using inductively-coupled plasma optical emission spectrometry (ICP-OES). The metal pollution index (MPI) was also calculated. Supporting analyses for the detection of the municipal wastewater presence at investigated localities included analyses of microbiological indicators (total coliforms and Escherichia coli) of faecal pollution. We have assessed biomarker responses from molecular to organism level using the condition index, comet assay, micronucleus test, oxidative stress parameters, histopathological alterations, and fluorescence spectroscopy parameters. Multibiomarker analysis was summarized by Integrated Biomarker Response v2 (IBRv2). Among these locations, Kruščica exhibited the lowest, whereas the Pek River displayed the highest values for both categories of indicator bacteria. Due to the porphyry copper ores mining, individuals from Pek River had several times higher Cu concentrations in both gills and liver compared to the other localities which was confirmed by biomarker responses and IBRv2 value. On the contrary, fish from Kruščica reservoir were the least affected by elemental pollution which is also confirmed by low MPI and IBRv2 values. Responses of biomarkers correspond to the elemental accumulation in the liver and gills of the Ibar River are positioned between the Pek River and Kruščica reservoir. Of all the biomarkers analyzed in this study, the condition index was the least sensitive. The results of this study showed that fluorescence spectroscopy may be a method for fast screening of structural changes in gills caused by the pollution burden
Streamlining Scanning Electron Microscopy (SEM) Sample Preparation Protocols for Analyzing the Mechanisms of Heavy Metal Bioremediation by Microalgae
No full textMicroalgae are shown to be a promising solution for phytoremediation of metal-polluted aquatic sites through several mechanisms, such as metal binding to the cell wall and/or the
formation of excreted polymers (mucilage). This way microalgae cells mitigate metal toxicity through the formation of metal complexes with polysaccharides that allow the gradual intake
of metals as a part of both physiological and adaptive response (buffering). Herein, we used
SEM to examine the morphological response of metabolically active green cell type of Haematococcus pluvialis (microzooids) to high manganese (Mn) concentrations exceeding their
physiological quota. The aim was to optimize the fixation protocol that preserves the mucilage
and other extracellular secreted cell- associated materials and maintains structural changes in the
outer cell wall architecture. After the initial use of glutaraldehyde for fixation, we applied two
different dehydration mixtures (graded concentrations of ethanol-water or acetic acid-ethanol
mixtures). Acetic acid and ethanol are routinely used for histological specimen fixation, while
the former allows dehydration without detrimental effects. Both dehydration mixtures gave
equal results with control cells (Fig 1A). Our SEM analysis revealed granular deposits on microzooid surfaces after 1 hour of the treatment using ethanol-water solution (Fig 1B) for gradual dehydration while such response was mainly omitted using an acetic acid-ethanol mixture (Fig
1C). The size and surface of these cells have changed from mainly smooth to more shrunken
with a considerably wrinkled surface in both cases compared to the control. These results indicate the possible presence of acid-soluble polysaccharides in mucilage, similar to the pectin from marine macroalgae species which in the presence of acid converts from the insoluble form
of protopectin to the water-soluble form. Ethanol proved to be the solvent of choice for this
kind of sample dehydration since it reduces the degradation of biomolecules present in samples, but one must proceed with caution as excessive cell shrinkage remains a potential issue
Adaptive responses and morphological changes in Chlamydomonas acidophila under sublethal manganese exposure
No full textMicroalgae have developed various accommodation/survival strategies for extreme conditions
which may facilitate their implementation as an emerging and prospective approach in heavy
metal remediation. Extremophile green algae species such as Chlamydomonas acidophila survive
in both acidic and metal-rich conditions using adaptive mechanisms that are poorly explored.
Herein, the adaptive response to high but sublethal manganese concentrations and the resulting
ultrastructural changes, redox properties, and energy reserves content were examined. After the
significant alterations of the cellular morphology observed in the first 24h, there were no signs of
further cell decay at the 48h. The most prominent morphological changes were extended granular endoplasmic reticulum (GER) cisternae and mitochondria with less sharply delineated and reduced cristae density and increased surface area. The obvious GER stress could relate to increased production of reactive oxygen species. Although the morphology of mitochondria was altered, there appear not to be any changes in energy reserves – glucose and lipids. There is a positive feedback loop between GER and mitochondria stress and oxidative stress, amplifying each other. Further investigations could give insight into the mechanisms that preserve the energy metabolism of the microalgae cell in oxidative stress condition
IS REDOX-HYPERACTIVITY IN EXTREMOPHILIC MICROALGAE LINKED TO THEIR INCREASED METABOLIC BURDEN?
No full textThe diverse uses of microalgae in ecological remediation, wastewater treatment,
pharmaceutics, or food and biofuel production, have long kept these single-celled organisms in the spotlight. The focus of this study was on Chlamydomonas acidophila
strain PM01, which thrives in acidic aquatic systems and is resistant to the presence of
heavy metals in its environment. The redox metabolism of this microalga was assessed
by its ability to reduce the EPR-active spin probe TEMPO (2,2,6,6-tetramethylpiper idine-1-oxyl), and compared to that of Chlorella sorokiniana strain CCAP 211/8K, a
freshwater green microalga. The results showed that C. acidophila has a faster redox
metabolic rate than C. sorokiniana, reducing 50% of TEMPO after 2.5, and 13 min,
respectively. The addition of Mn2+ or Fe3+ to the culture medium of C. acidophila did
not affect its reduction capacity, while it had a minor effect on C. sorokiniana. The
faster rate in C. acidophila most likely represents the result of its adaptation to acidic
environments. Namely, it has previously been suggested that acidophilic algae perform
energy-demanding cellular processes in order to cope with the high pH gradient across
the membrane. Moreover, the increased metabolic turnover requires an increased mi tochondrial activity, resulting in a higher baseline production of superoxide and hydro gen-peroxide, subsequently compensated by an elevated baseline reduction capacity.
Interestingly, the redox metabolic rate of C. sorokiniana was unaltered in suspensions
that were kept in non-standard cultivation conditions (diurnal fluctuations of tempera ture and ambient lighting, absence of shaking) for five weeks. However, C. acidophila
lost all of its reduction capacity in these conditions already after three days. These
findings may be important when selecting the most appropriate microalgal strain for
a specific application. Specifically, C. acidophila would likely be a good candidate for
high-yield rapid production of endogenous products that are the result of its unique
survival mechanism under extreme conditions.U pitanju je prvo izdanje časopisa u kome su štampani apstrakti sa konferencije, pa vodim to kao konferenciju
Fluorescence Spectroscopy and Advanced Mathematic Algorithm in Analyzing Honey – Recent Trends and Future Outlooks
No full textFluorescence spectroscopy (FS) is a highly sensitive optical technique
widely used to assess food quality and safety, particularly in the case of
honey and its products. Honey contains different compounds with
intrinsic fluorescence (e.g. proteins, phenolics) and non- fluorescent
compounds like sugar, minerals etc. Honey, as a complex system with
multiple fluorphores, presents a challenge for spectral analysis due to
the high overlap of fluorescence signals. Advanced mathematical
methods (AMM) have been used to extract significant information
regarding the chemical structure of components in various honey
samples. Our previous research has shown successful applications of
algorithms like multivariate curve resolution (MCR-ALS) and PARAFAC
in the fluorescence spectral analysis of honey. Rapid detection of
contaminants, like chemical pesticides, is crucial for protecting both
honey consumers and beekeepers. Additionally, understanding how
bees are treated by beekeepers is important. We have used optical tools
combined with AMMs to gain insights into the health status of bees,
while also discussing advancements and providing a future outlook for
the use of optical sensor systems in honey quality assessment
Фактори угрожавања риба у Србији“. Црвена књига фауне Србије V – Рибе.
No full textSlatkovodni ekosistemi zauzimaju svega 0,8% Zemljine površine
(odnosno 0,01% celokupne vode na Zemlji), njihova uloga u
svim prirodnim procesima i ciklusima veoma je važna (Dudgeon et
al., 2006). Pružaju brojne ekosistemske usluge i predstavljaju dom za
oko 12% (preko 140.000) svih do sada poznatih i opisanih životinjskih
vrsta, odnosno 47–53% (~18.000) vrsta riba (Nelson, 2006; Reid
et al., 2019). Kopnene vode i slatkovodni biodiverzitet predstavljaju
važan prirodni resurs u ekonomskom, kulturnom, estetskom, naučnom
i edukativnom smislu. Očuvanje i upravljanje ovim resursom
od ključne je važnosti za čitavo čovečanstvo (Reid et al., 2013). Nažalost,
ovo dragoceno nasleđe danas je u velikoj krizi. Slatkovodne
vrste životinja izumiru znatno brže od terestričnih i marinskih. Više
od trećine nalazi se pred izumiranjem, a smatra se da će problem postati
još veći kako raste brojnost ljudske populacije (Dudgeon et al.,
2006; IUCN Freshwater Fish Specialist Group, 2020b)
A Review of Endophytic Fungi and their Applications in Different Fields of Biotechnology
No full textEndophytic fungus is an intriguing group of organisms that live inside their host's living tissues, which are primarily higher
plants. Endophytes generate naturally occurring bioactive chemicals that are thought to operate as an elicitor for the synthesis
of secondary metabolites in plants, without causing any disease symptoms in the host cells. By imparting stress tolerance and
enhancing host resistance to a range of diseases, this incredibly varied collection of fungus can have a significant influence on
plant ecosystems. They are known to improve nutrition through the reversible exchange of nutrients and protect plants from
infections, which in turn affects development by releasing plant growth hormones. Endophytic fungus-infected plants exhibit
notable increases in biomass, enhance commercial plant output, and are therefore beneficial to the agricultural industry.
The potential uses of endophytic fungi as biological vectors, biological control agents, and insecticidal products, sources
of secondary metabolites, antimicrobial agents, antitumor compounds, antibiotics, immunosuppressants, and antidiabetic
agents make them of biotechnological interest. The current study concentrated on the numerous uses of fungal endophytes in
several biotechnology fields
Immobilization of periodate-oxidized horseradish peroxidase by adsorption on sepiolite
No full textHorseradish peroxidases (HRP), native and periodate-oxidized were
immobilized onto sepiolite clay mineral by adsorption. Both peroxidases were
adsorbed on this carrier in different quantities. Specific activity of immobilized
enzymes was increased with increasing the amount of peroxidase added per gram
of sepiolite. The highest specific activity was achieved when 15 mg of perox
idase was added per g of sepiolite. Also, periodate-oxidized enzymes showed
similar specific activity as native ones. Stability studies (pH, thermal and oper
ational stability) were conducted for both peroxidases. Residual specific activity
of HRP immobilized onto sepiolite declined with an increase of incubation time
at 65 °C. Oxidized-peroxidase lost 64 % of the initial activity, whereas native
HRP dropped 92 % of its activity after 5 min of incubation at 65 °C. Reduction
of the enzyme activity was observed with the temperature increase from 30 to 80
°C. pH profiles of native peroxidase immobilized onto sepiolite were higher in
both acidic and basic regions compared to periodate-oxidized enzyme. Oxidized
HRP was more successful in studies of operational stability, it retained 42 % of
its activity after 4 consecutive cycles of pyrogallol oxidation, whereas native
peroxidase kept only 11 % of the original activity
Sustainable Removal of Cr(VI) from Wastewater Using Green Composites of Zero-Valent Iron and Natural Clays
No full textComposites for efficient removal of hexavalent chromium Cr(VI) from industrial wastewater were obtained by deposition of nano-zero-valent iron (nZVI), synthesized by environmentally friendly synthesis using oak leaf extract, on inexpensive, natural, readily available and cheap natural raw materials, sepiolite (SEP) or kaolinite/illite (KUb) clay, as support. nZVI particles were deposited from the FeCl3 solution of different concentrations, with the same volume ratio extract/FeCl3 solution (3:1), and with different masses of SEP or KUb. Physico–chemical characterization (SEM/EDS, FTIR, BET, determination of point of zero charge) of the composites and nZVI was performed. The results of SEM and BET analyses suggested more homogeneous deposition of nZVI onto SEP than onto KUb, which ensures greater availability of the nZVI surface for Cr(VI) anions. Therefore, the higher Cr(VI) removal at all investigated initial pH values (pHi) of the solution (3, 4 and 5) was achieved with the SEP composites. The adsorption results indicated that the elimination of Cr(VI) was achieved via the combined effect of reduction and adsorption. The removal of total chromium at pHi = 3 was approximately the same as that of Cr(VI) removal for the KUb composites, but lower for the SEP composites, indicating lower removal of Cr(III) compared to the reduced Cr(VI). The SEP/nZVI composite with the highest removal efficiency was applied for Cr(VI) removal from real wastewater at pHi = 3 and pHi = 5. The results demonstrated the high Cr(VI) removal capacity, validated the assumption that a good dispersion of nZVI particles is beneficial for Cr(VI) removal and showed that the produced green composites can be efficient materials for the removal of Cr(VI) from wastewater
CARPATHIAN BROOK LAMPREY Eudontomyzon danfordi Regan, 1911
No full textKARPATSKA PAKLARA
Eudontomyzon danfordi Regan, 1911
CARPATHIAN BROOK LAMPREY
Eudontomyzon danfordi Regan, 1911Oblik tela karpatske paklare sličan je jegulji, sa sedam okruglih
škržnih otvora iza oka (Slika 137). Paklare imaju karakterističan
oralni disk koji im služi da se prikače za podlogu ili plen. Glava i
leđa su plavo-sive boje, bočna strana ide od sive prema ružičastoj nijansi,
dok je trbuh beo. Bočna linija nije pigmentisana. Karakteriše
se odsustvom parnih peraja i vilica. Trup ima 58–70 miomera, nije
istačkan (išaran) kod larvi, a repno peraje je bezbojno i providno.
Prosečna dužina tela je oko 18 cm; adultne jedinke mogu narasti do
30 cm, a larve do 24,5 cm. Maksimalna zabeležena starost iznosi 7
godina (Renaud & Holčík, 1986).
The body of the Carpathian brook lamprey resembles that of an
eel, with seven round gill openings behind the eye (Figure 137). The
lampreys have a characteristic oral disc with which they cling to the
substrate or prey. The head and back are blue-grey, the flanks change
from grey to a pinkish hue, while the belly is white. The lateral line is
not pigmented. It is distinguished by the absence of paired fins and
jaws. The trunk has 58–70 myomeres, it is not spotted (mottled) in
larvae, and the caudal fin is colourless and hyaline. The average body
length is about 18 cm; adults can grow up to 30 cm and larvae up to
24.5 cm long. The maximum age is 7 years (Renaud & Holčík, 1986)