Effects of fish farming on microbial planktonic communities in the middle Adriatic sea          下载免费PDF全文

Stefanija Šestanović  Jelena Peković  Slavica Matijević  Živana Ninčević Gladan 《Aquaculture Research》2016,47(4):1040-1054

The effects of farming on planktonic microbial communities were investigated at the coastal sea bass/sea bream farm in the oligotrophic middle Adriatic Sea. Analyses of nutrients, chlorophyll a, cyanobacteria (Prochlorococcus), heterotrophic bacteria and nanoflagellates (both pigmented and heterotrophic) were carried out on samples taken during six seasonal cruises at different water depths. Farming activity increased the natural concentrations of some nutrients (ammonium, nitrite, phosphate, dissolved inorganic nitrogen) and changed their seasonal pattern. The values still remained typical for oligotrophic environ‐ments demonstrating no risk for eutrophication. Enhanced nutrient supply provoked an immediate increase in abundances of both autotrophic and heterotrophic microbial groups (except pigmented nanoflagellates) and chlorophyll a. The effect of farming was more visible for the heterotrophic microbial component. Results from this study reveal a potential common pattern of microbial response to farming in the oligotrophic environments. It also suggests the importance of heterotrophic microbial web in transferring the matter and energy released from the fish farms in nutrient poor environments.  相似文献   

Phylogenetic comparison of porcine circovirus type 2 (PCV2) and porcine reproductive respiratory syndrome virus (PRRSV) strains detected in domestic pigs until 2008 and in 2012 in Croatia     

Jelena Prpi?  Tomislav Keros  Tomislav Bedekovi?  Dragan Brni?  ?eljko Cvetni?  Besi Roi?  Lorena Jemer?i? 《Irish veterinary journal》2014,67(1):9

Background

Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been present for the last 2 decades in Croatia, causing large economical losses in the pig production. The clinical features of the infections are mostly manifested by the development of respiratory problems, weight loss and poor growth performance, as well as reproductive failure in pregnant sows. Even though the infections are continuously recognized in some regions in Croatia, the heterogeneity of the detected viral strains from 2012 has not yet been investigated. The objective of this study was to compare virus strains of PCV2 and PRRSV detected until 2008 in Croatia with strains isolated in 2012 to gain a better epidemiological understanding of these two infections.

Results

PCV2 and PRRSV strains detected in 2012 in fattening pigs from regions where these two diseases have been previously described were compared to strains that have been detected in the same regions within the past two decades. The phylogenetic analysis revealed that the circulating PCV2 and PRRSV strains are distantly related to the previously described Croatian viral strains. However, when compared to known isolates from the GenBank a high genetic identity of PRRSV isolates with isolates from Hungary, Denmark and the Netherlands was found.

Conclusion

The results of this study reveal that even though PCV2 and PRRSV are constantly present in the investigated regions in Croatia, the viral strains found in 2012 genetically differ from those detected in earlier years. This indicates that new entries into the pig population appeared with regard to both infections, probably as a result of pig trade.  相似文献   

Heavy Metal Content of Soils and Plum Orchards in an Uncontaminated Area     

Bošković-Rakočević  Ljiljana  Milivojević  Jelena  Milošević  Tomo  Paunović  Gorica 《Water, air, and soil pollution》2014,225(11):1-13

There are multiple stressors derived from urbanizations that result in frequent disturbances on streams and rivers reducing water quality and threatens aquatic biota. P-glycoprotein (P-gp)-mediated multixenobiotic resistance (MXR) is a defence mechanism analogous to multidrug resistance (MDR), which has been demonstrated in several aquatic organisms. This system protects cells against the entry and the accumulation of xenobiotics and has been proposed as a biomarker for pollution assessment. We conducted a study in a post-urban reach of Esquel stream (Chubut Province) downstream a wastewater treatment plant, in order to assess the presence and activity of MXR in five freshwater macroinvertebrate species (Helobdella michaelseni, Helobdella simplex, Patagoniobdella variabilis, Hyalella curvispina and Chironomus riparius). We measured the accumulation of the model P-gp substrate rhodamine B (RB) in organisms previously exposed to pollution. Our results described the activity of the MXR system in the three species of leeches suggesting their suitability as the in vivo biomonitoring. We also identified a dependence of the transporter activity with the development stage in H. simplex, highlighting the importance of using organisms of similar size classes since it may affect observed results. Finally, we concluded that benthic freshwater macroinvertebrates possess different species-specific levels of MXR activity possibly influencing their natural distribution as well as their survival.  相似文献   

Influence of N-, P- and Si-based Flame Retardant Mixtures on Flammability,Thermal Behavior and Mechanical Properties of PA6 Composite Fibers     

Alisa Šehić  Jelena Vasiljević  Igor Jordanov  Andrej Demšar  Jožef Medved  Ivan Jerman  Marija Čolović  Fiona Hewitt  T. Richard Hull  Barbara Simončič 《Fibers and Polymers》2018,19(6):1194-1206

This research investigated the influence of two flame retardant (FR) mixtures consisting melamine cyanurate (MeCy) and aluminum diethylphosphinate (AlPi), and MeCy and sodium aluminosilicate (SASi) at different weight ratios, on the flammability, thermal behavior and mechanical properties of polyamide 6 (PA6) composite yarns produced by meltspinning. The morphological and chemical properties of PA6/FR filaments were investigated by scanning electron microscopy and Fourier-transform infrared spectroscopy, flame retardancy by vertical burning test UL-94, thermal behavior by thermogravimetric and differential scanning calorimetric analyses, and mechanical properties by tensile tests. The results indicate that within the UL 94 V2 rating, the composite yarns differed significantly from each other in their burning and dripping behavior. The incorporation of both mixtures, MeCy+AlPi and MeCy+SASi, into the PA6/FR yarns significantly decreased the afterflame time relative to pristine PA6, confirming a lower production of flammable volatiles. This phenomenon was attributed mainly to MeCy, which caused an immediate extinguishment of the flame after the withdrawal of the igniting flame. Compared to one component MeCy, the incorporation of the MeCy+SASi mixture enhanced the thermooxidative stability of the PA6/FR yarns because of their additive effect at higher concentrations. In contrast, an antagonistic effect was obtained for the MeCy+AlPi mixture, irrespective of the concentration. Since the incorporation of MeCy+SASi did not drastically reduce the tensile properties of filaments, this mixture enables the production of the PA6/MeCy+SASi composite yarns with the enhanced flame retardancy and thermo-oxidative stability.  相似文献   

Development of sperm vitrification protocols for two endangered salmonid species: the Adriatic grayling, <Emphasis Type="Italic">Thymallus thymallus</Emphasis>, and the marble trout, <Emphasis Type="Italic">Salmo marmoratus</Emphasis>     

Eszter Kása  Jelena Lujić  Zoran Marinović  Tímea Kollár  Gergely Bernáth  Zoltán Bokor  Béla Urbányi  Kinga Katalin Lefler  Dušan Jesenšek  Ákos Horváth 《Fish physiology and biochemistry》2018,44(6):1499-1507

Vitrification was applied to the sperm of two endangered fish species of So?a River basin in Slovenia, the Adriatic grayling (Thymallus thymallus) and marble trout (Salmo marmoratus) following testing different cooling devices and vitrifying media. Sperm was collected, diluted in species-specific non-activating media containing cryoprotectants, and vitrified by plunging directly into liquid nitrogen without pre-cooling. Progressive motility, curvilinear velocity, and straightness of fresh and vitrified-warmed sperm were evaluated with computer-assisted sperm analysis (CASA). Fertilization trials were carried out to test the effectiveness of vitrification in the case of grayling. A protocol utilizing a glucose-based extender, 30% cryoprotectants (15% methanol + 15% propylene glycol), 1:1 dilution ratio, and droplets of 2 μl on a Cryotop as cooling device yielded the highest post-thaw motility values for both Adriatic grayling (7.5?±?6.5%) and marble trout (26.6?±?15.8%). Viable embryos were produced by fertilizing eggs with vitrified grayling sperm (hatching 13.1?±?11.7%, control hatching 73.9?±?10.4%). The vitrification protocol developed in this study can be utilized in the conservation efforts for the two species as an alternative to slow-rate freezing when working in field conditions or when specific equipment necessary for slow-rate freezing is not available.  相似文献   

Biological control of green mould on <Emphasis Type="Italic">Agaricus bisporus</Emphasis> by a native <Emphasis Type="Italic">Bacillus subtilis</Emphasis> strain from mushroom compost     

Svetlana Milijašević-Marčić  Miloš Stepanović  Biljana Todorović  Bojan Duduk  Jelena Stepanović  Emil Rekanović  Ivana Potočnik 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(3):509-519

Fifty bacterial isolates obtained from compost were tested in vitro against the causal agents of green mould in Agaricus bisporus. Isolate B-38 which induced 48.08% in vitro growth inhibition of T. harzianum T54 and 52.25% of T. aggressivum f. europaeum T77 was identified as Bacillus subtilis, based on 16S rDNA sequence and used in mushroom growing room experiments. B. subtilis B-38 did not decrease mycelial growth rate of Agaricus bisporus A15 in mushroom compost in glass tubes. After applying prochloraz-manganese, B. subtilis B-38 and B. subtilis QST 713, no significant differences in BE values among treatments were found concerning both total yield and the weight of healthy mushrooms. Statistical analyses showed that only inoculation significantly influenced the healthy mushroom yield. In plots inoculated with T. harzianum T54 disease incidence was significantly lower after treatments with prochloraz-manganese (11.81%), B. subtilis QST 713 (12.26%) and B. subtilis B-38 (14.19%) compared to the control (28.16%), as well as in plots inoculated with T. aggressivum f. europaeum T77 11.88%, 12.2% and 15.03%, respectively, in comparison with the control (23.47%). Statistically significant differences were not found among the efficacy values of tested bio-fungicides based on B. subtilis and the commercial fungicide prochloraz-manganese suggesting the use of B. subtilis B-38 and B. subtilis QST 713 as good alternatives to chemical fungicides.  相似文献   

Effects of chronic sub‐lethal nitrite exposure at high water chloride concentration on Atlantic salmon (Salmo salar,Linnaeus 1758) parr     

Xavier A. Gutirrez  Jelena Kolarevic  Harald Takle  Grete Baeverfjord  Elisabeth Ytteborg  Bendik Fyhn Terjesen 《Aquaculture Research》2019,50(9):2687-2697

The present study examined the protective effects of water chloride (Cl^?) towards nitrite toxicity in Atlantic salmon parr during 84‐day long nitrite exposure. Effects on growth, histology, blood indices and gene expression were studied at a fixed nominal Cl^? concentration of 200 mg/L and at several water nitrite concentrations (0, 0.5, 2, 5 and 10 mg/L NO₂^?–N). The specific growth rate was significantly reduced during the first three weeks at a Cl:NO₂^?–N ratio of 21:1, suggesting the activation of coping mechanisms at the later stages of the experiment. No significant effect of nitrite on gill histology and mortality was found. Nitrite accumulated in plasma; however, a Cl:NO₂^?–N ratio of 104:1 or higher prevented nitrite entry. The concentration of NO₂^?–N in plasma was significantly reduced at the end of the study, supporting the hypothesis of coping mechanisms. Cystic fibrosis transmembrane conductance regulator (cftr)‐1 showed a significant up‐regulation at highest nitrite concentration on day 22, and in three of the highest exposure groups at the end of the experiment. Our findings suggest that a Cl:NO₂^?–N ratio above 104:1 should be maintained through episodes of nitrite accumulation in water during the production of Atlantic salmon parr.  相似文献   

Antioxidative enzymes in the response of buckwheat (Fagopyrum esculentum moench) to ultraviolet B radiation   总被引：2，自引：0，他引：2  

Jovanovic ZS  Milosevic JD  Radovic SR 《Journal of agricultural and food chemistry》2006,54(25):9472-9478

The behavior of the enzymatic antioxidant defense system was studied in buckwheat leaves and seedlings subjected to short-term enhanced UV-B radiation. The effects of UV-B action were monitored immediately after irradiation as well as after recovery. The applied dose induced an increase in lipid peroxidation and total flavonoid content, a decrease in chlorophyll content, and a change in enzymatic digestibility of extracted DNA. The activity of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase, and soluble peroxidase, as well as the isoelectric focusing (IEF) pattern of peroxidase isoforms, was analyzed. In treated as well as recovered seedlings, soluble and ascorbate peroxidase activities were increased. The activity of SOD was not altered, whereas CAT activity was decreased. In contrast to seedlings, only CAT activity was increased in treated and recovered leaves.  相似文献   

Antifungal activities of silver and selenium nanoparticles stabilized with different surface coating agents     

Karolina Vrande i&#x;  Jasenka &#x;osi&#x;  Jelena Ili&#x;  Boris Ravnjak  Ati&#x;a Selmani  Emerik Gali&#x;  Barbara Pem  Rinea Barbir  Ivana Vinkovi&#x; Vr ek  Tomislav Vinkovi&#x; 《Pest management science》2020,76(6):2021-2029

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Tank size and fish management history matters in experimental design          下载免费PDF全文

Åsa Maria Espmark  Jelena Kolarevic  Torbjørn Åsgård  Bendik Fyhn Terjesen 《Aquaculture Research》2017,48(6):2876-2894

To investigate the questions: (1) does tank size affect fish performance; (2) does tank size prior to an experiment affect later fish performance and (3) how does performance in experimental tanks compare with rearing in industry‐scale cages, Atlantic salmon smolts were acclimatized to 190, 3 or 0.9 m³ tanks (Phase 1; 1.5 months) before redistributed to Phase 2 for 5 months. Question 1: fish in 190 m³ tank were redistributed to 0.9 m³ (190 m³ → 0.9 m³), 3 m³ (190 m³ → 3 m³), or 103 m³ (190 m³ → 103 m³) tanks. Question 2: fish in 0.9 m³ tanks were redistributed to 3 m³ tanks (0.9 m³ → 3 m³), and compared to fish from 190 m³ tank (190 m³ → 3 m³). Question 3: fish were placed directly in 3 m³ tanks, not moved (3 m³ → 3 m³), and compared to reference sea cages. Phase 2 mortality: 190 m³ → 0.9 m³ (46%), 190 m³ → 3 m³ (29%), 190 m³ → 103 m³ (19%), 3 m³ → 3 m³ and 0.9 m³ → 3 m³ (<5%). Most mortality happened shortly after transfer. Our study suggests tank size dependent performance, based on growth and feed intake that increased with tank size. 190 m³ → 103 m³ fish were more active than 190 m³ → 0.9 m³ and 190 m³ → 3 m³ fish. 190 m³ → 103 m³ tanks had lowest relative variance. Previous tank scale history affected survival, since 0.9 m³ → 3 m³ fish showed higher survival than 190 m³ → 3 m³ fish. However, previous scale history did not affect growth rate, feed intake or somatic indexes. Fish performance in 3 m³ → 3 m³ tanks did not differ from the reference sea cages. However, fish in 103 m³ tanks performed better than reference cages, suggesting potential for improved commercial production. This study demonstrates that management practices can influence fish performance and should be taken into account when designing experiments.  相似文献