Who is the better candidate? Macroinvertebrates and diatoms for ecological status assessment of Sava Lake (Serbia)

Sava Lake was created from the right arm of the Sava River, and the inhabitants of Belgrade use the lake intensively for swimming and bathing. We analysed macrozoobenthos and epilithic diatom communities at six sites from April to October 2017, to assess the ecological status of Sava Lake according to the National legislation of Serbia. Considering macrozoobenthos communities, the mean values of Zelinka and Marvan saprobity index indicated high ecological status. In contrast, results obtained from the mean values of BMWP (Biological Monitoring Working Party) scores suggested moderate to poor ecological status. The mean values of the IPS diatom index (Indice de Polluo-sensibilité) indicated high ecological status, while the TDIL index (Trophic Diatom Index for lakes) was slightly more sensitive and indicated good ecological status. Water chemical parameters indicated that Sava Lake was mainly oligotrophic during the study period (average total phosphorus concentrations were 10.7 μgL-1 and average total nitrogen concentrations 410 μgL-1). Before being able to adopt an integrative approach for ecological status assessment (combining two or more biological quality elements), more studies must be performed on how to choose the most sensitive and adequate indices. This is especially true for lakes experiencing intensive anthropogenic pressure during the summer season. Also, the boundary values in the National legislation of Serbia must be adapted for lakes, such as Sava Lake.11th Symposium for European Freshwater Sciences, June 30–July 5, 2019, Zagreb, Croatia, [http://www.sefs11.biol.pmf.hr/

Relating environmental pressures to littoral biological water quality indicators in Western Balkan lakes: Can we fill the largest gaps?

Along six transects in each of six lakes across the Western Balkans, we collected data for three groups of littoral biological water quality indicators: epilithic diatoms, macrophytes, and benthic invertebrates. We assessed the relationships between them and three environmental pressures: nutrient load (eutrophication), hydro-morphological alteration of the shoreline, and water level variation, separating the effect of individual lakes and continuous explanatory variables. Lake water total phosphorus concentration (TP) showed substantial variation but was not related to any of the tested biological indicators, nor to any of the tested pressures. We suggest that this may be due to feedback processes such as P removal in the lake littoral zone. Instead, we found that a gradient in surrounding land-use towards increasing urbanization, and a land-use-based estimate of P run-off, served as a better descriptor of eutrophication. Overall, eutrophication and water level fluctuation were most important for explaining variation in the assessed indicators, whereas shoreline hydro-morphological alteration was less important. Diatom indicators were most responsive to all three pressures, whereas macrophyte biomass and species number responded only to water level fluctuation. The Trophic Diatom Index for Lakes (TDIL) was negatively related to urbanization and wave exposure. This indicates that it is a suitable indicator for pressures related to urbanization, although a confounding effect of wave exposure is possible. Invertebrate abundance responded strongly to eutrophication, but the indicator based on taxonomic composition (Average Score Per Taxon) did not. Our results suggest that our metrics can be applied in Western Balkan lakes, despite the high number of endemic species present in some of these lakes. We argue that local water management should focus on abating the causes of eutrophication and water level fluctuation, whilst preserving sufficient lengths of undeveloped shoreline to ensure good water quality in the long run

Cultivation of edible filamentous fungi on pomegranate by-products as feedstocks to produce mycoprotein

Pomegranate, renowned for its delectable taste and remarkable nutritional profile, has witnessed a surge in both production and consumption. However, the by-products generated during industrial processes, such as peels and seeds, have the potential for adverse environmental impacts if not meticulously managed. Similarly, expired fruit juices or spillages that may occur during manufacturing and transportation contribute to agri-food waste. This study focused on the comprehensive assessment of pomegranate by-products and pomegranate juice using ascomycetes and zygomycetes filamentous fungi, namely Aspergillus oryzae, Rhizopus oligosporus, and Neurospora intermedia to obtain mycoprotein for sustainable vegan food production. The findings revealed that pomegranate juice, both fresh and expired commercial, contained essential nutrients for fungal biomass production (up to 0.024 g biomass/mL juice). Nonetheless, fresh juice emerges as a more potent medium in terms of protein production than commercial juice. Cultivating A. oryzae yielded a biomass of 0.39 (g biomass/g peel) from pomegranate peel, while concurrently raising the protein content of raw pomegranate peel from 30.89 g/kg to 85.41 g/kg. Furthermore, incorporating yeast extract into the peel medium not only resulted in an enhanced biomass yield of 0.49 (g biomass/g peel) but also significantly elevated the protein content to 198.63 g/kg. This study provides valuable insights into the potential of pomegranate peel and juice as promising substrate for fungal biomass production, offering opportunities for the development of innovative food and feed products.

Novel Perspectives on Food-Based Natural Antimicrobials: A Review of Recent Findings Published since 2020

Various fruit and vegetable wastes, particularly peels, seeds, pulp, and unprocessed residues from the food industry, are abundant sources of antioxidants and essential antimicrobial agents. These valuable bioactive compounds recovered from the food industry have a great application in food, agriculture, medicine, and pharmacology. Food-derived natural antimicrobials offer advantages such as diminishing microbial loads and prolonging the shelf life of food products particularly prone to microbial spoilage. They not only enrich the foods with antioxidants but also help prevent microbial contamination, thereby prolonging their shelf life. Similarly, incorporating these natural antimicrobials into food packaging products extends the shelf life of meat products. Moreover, in agricultural practices, these natural antimicrobials act as eco-friendly pesticides, eliminating phytopathogenic microbes responsible for causing plant diseases. In medicine and pharmacology, they are being explored as potential therapeutic agents. This review article is based on current studies conducted in the last four years, evaluating the effectiveness of food-based natural antimicrobials in food, agriculture, medicine, and pharmacology

Testing the applicability of diatom indices for ecological assessment of Balkan lakes

During 2016-2017 six Balkan lakes were investigated: Sava Lake in Serbia, Ohrid Lake and Prespa Lake in North Macedonia and Albania, Great Lake in Albania, Biogradsko Lake and Crno Lake in Montenegro. Epilithic diatom samples were collected from 6 localities around each lake with the aim to test the applicability of diatom indices for ecological assessment of Balkan lakes. Also, water samples for chemical analysis were taken. Based on the concentrations of total phosphorus and BOD (biochemical oxygen demand) two lakes (Ohrid and Crno) were oligotrophic and oligosaprobic, while the other four lakes were mesotrophic and β-mesosaprobic, respectively. The highest diversity of dominant taxa was recorded in Ohrid and Prespa, and one of the dominant taxa was the endemic species Gomphonema paratergestinum. Diatom communities in lakes Sava and Crno were dominated by Achnanthidim minutissimum and Encyonopsis microcephala. According to Serbian legislation, the IPS index is used for the assessment of the ecological status of lakes, while in North Macedonia, Albania and Montenegro National Monitoring Systems do not yet include officially accepted diatom indices. In our results, the diatom indices IPS and IBD had the highest inclusion of diatom taxa, in some lakes almost 100%. The lowest inclusion of diatom taxa had the TDIL index. Values of IPS and IBD indices indicated very good water quality for Great Lake, Crno and Biogradsko, and good for Prespa. The water quality of Ohrid and Sava was between very good and good. Values of trophic indices (Rott TI and TDIL) indicated a very low concentration of nutrients in the Sava, Great Lake and Biogradsko, low in Ohrid and Prespa and low to the very low concentration of nutrients in Crno. The development and establishment of monitoring systems in lakes according to the requirements of the Water Framework Directive (WFD) is essential for all European countries and more comprehensive ecological investigations of Balkan lakes are necessary to be able to fulfill these demands.7th European Phycological Congress, Zagreb, Croatia, 25-30.08.201

Littoral eutrophication indicators are more closely related to nearshore land use than to water nutrient concentrations: A critical evaluation of stressor-response relationships

Biological assessment metrics and water chemistry measurements are used to quantify the link between stressors and their effects on lake ecosystems, for the Water Framework Directive. However, correlations between metrics and water chemistry are often poor. This is seen as major weaknesses of Water Framework Directive-related monitoring and assessment. We analyzed macrophytes, benthic algae, benthic macroinvertebrates, water chemistry and sediment total phosphorus content in the littoral of six lakes in the Western Balkans and used CORINE land use data to estimate nutrient enrichment via runoff from the adjacent land. Lakes with a higher estimated phosphorus runoff from the adjacent land did not have higher littoral water nutrient concentrations, but littoral diatom assemblages indicated more eutrophic conditions. These lakes also had higher abundances of littoral benthic primary producers, which in turn were associated with low concentrations of dissolved nutrients, but only in autumn, not in spring. This is consistent with primary producers taking up nutrients during the summer growth season. In lakes with high abundances of benthic primary producers, it is likely that the littoral vegetation plays a large role in the transfer of nutrients from the water to the benthos. This process impairs correlations between biological metrics and water nutrient concentrations. Our results suggest that CORINE land cover may be more useful to characterize littoral nutrient enrichment than lake water chemistry. Increased benthic primary producer biomasses and “eutrophic” diatom indices may indicate littoral nutrient enrichment even if water nutrient concentrations are low

Littoral eutrophication indicators are more closely related to nearshore land use than to water nutrient concentrations: A critical evaluation of stressor-response relationships

Biological assessment metrics and water chemistry measurements are used to quantify the link between stressors and their effects on lake ecosystems, for the Water Framework Directive. However, correlations between metrics and water chemistry are often poor. This is seen as major weaknesses of Water Framework Directive-related monitoring and assessment. We analyzed macrophytes, benthic algae, benthic macroinvertebrates, water chemistry and sediment total phosphorus content in the littoral of six lakes in the Western Balkans and used CORINE land use data to estimate nutrient enrichment via runoff from the adjacent land. Lakes with a higher estimated phosphorus runoff from the adjacent land did not have higher littoral water nutrient concentrations, but littoral diatom assemblages indicated more eutrophic conditions. These lakes also had higher abundances of littoral benthic primary producers, which in turn were associated with low concentrations of dissolved nutrients, but only in autumn, not in spring. This is consistent with primary producers taking up nutrients during the summer growth season. In lakes with high abundances of benthic primary producers, it is likely that the littoral vegetation plays a large role in the transfer of nutrients from the water to the benthos. This process impairs correlations between biological metrics and water nutrient concentrations. Our results suggest that CORINE land cover may be more useful to characterize littoral nutrient enrichment than lake water chemistry. Increased benthic primary producer biomasses and “eutrophic” diatom indices may indicate littoral nutrient enrichment even if water nutrient concentrations are low

Littoral eutrophication indicators are more closely related to nearshore land use than to water nutrient concentrations: A critical evaluation of stressor-response relationships

Biological assessmentmetrics and water chemistry measurements are used to quantify the link between stressors and their effects on lake ecosystems, for the Water Framework Directive. However, correlations between metrics andwater chemistry are often poor. This is seen as majorweaknesses ofWater Framework Directive-relatedmonitoring and assessment.We analyzed macrophytes, benthic algae, benthic macroinvertebrates, water chemistry and sediment total phosphorus content in the littoral of six lakes in the Western Balkans and used CORINE land use data to estimate nutrient enrichment via runoff from the adjacent land. Lakes with a higher estimated phosphorus runoff fromthe adjacent land did not have higher littoralwater nutrient concentrations, but littoral diatom assemblages indicated more eutrophic conditions. These lakes also had higher abundances of littoral benthic primaryproducers, which in turnwere associatedwithlowconcentrations of dissolved nutrients, but only in autumn, not in spring. This is consistent with primary producers taking up nutrients during the summer growth season. In lakeswith high abundances of benthic primary producers, it is likely that the littoral vegetation plays a large role in the transfer of nutrients from the water to the benthos. This process impairs correlations between biological metrics and water nutrient concentrations. Our results suggest that CORINE land cover may be more useful to characterize littoral nutrient enrichment than lake water chemistry. Increased benthic primary producer biomasses and “eutrophic” diatom indicesmay indicate littoral nutrient enrichment even ifwater nutrient concentrations are lo