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The aim of this study is to investigate the effect of three daily fish feeding frequencies, two, four and eight times per day (FF2, FF4, and FF8, respectively) on growth performance of sea bass (Dicentrarchus labrax)and lettuce plants (Lactuca sativa) reared in aquaponics. 171 juvenile sea bass with an average body weight of 6.80 ± 0.095 g were used, together with 24 lettuce plants with an average initial height of 11.78 ± 0.074 cm over a 45-day trial period. FF2 fish group showed a significantly lower final weight, weight gain and specific growth rate than the FF4 and FF8 groups. Voluntary feed intake was similar for all the three feeding frequencies treatmens (p > 0.05). No plant mortality was observed during the 45-day study period. All three aquaponic systems resulted in a similar leaf fresh weight and fresh and dry aerial biomass. The results of the present study showed that the FF4 or FF8 feeding frequency contributes to the more efficient utilization of nutrients for better growth of sea bass adapted to fresh water while successfully supporting plant growth to a marketable biomass.
Paraskevi Stathopoulou; Panagiotis Berillis; Nikolaos Vlahos; Eleni Nikouli; Konstantinos A. Kormas; Efi Levizou; Nikolaos Katsoulas; Eleni Mente. Freshwater-adapted sea bass Dicentrarchus labrax feeding frequency impact in a lettuce Lactuca sativa aquaponics system. PeerJ 2021, 9, e11522 .
AMA StyleParaskevi Stathopoulou, Panagiotis Berillis, Nikolaos Vlahos, Eleni Nikouli, Konstantinos A. Kormas, Efi Levizou, Nikolaos Katsoulas, Eleni Mente. Freshwater-adapted sea bass Dicentrarchus labrax feeding frequency impact in a lettuce Lactuca sativa aquaponics system. PeerJ. 2021; 9 ():e11522.
Chicago/Turabian StyleParaskevi Stathopoulou; Panagiotis Berillis; Nikolaos Vlahos; Eleni Nikouli; Konstantinos A. Kormas; Efi Levizou; Nikolaos Katsoulas; Eleni Mente. 2021. "Freshwater-adapted sea bass Dicentrarchus labrax feeding frequency impact in a lettuce Lactuca sativa aquaponics system." PeerJ 9, no. : e11522.
The diversity and degradation capacity of hydrocarbon-degrading consortia from surface and deep waters of the Eastern Mediterranean Sea were studied in time-series experiments. Microcosms were set up in ONR7a medium at in situ temperatures of 25 °C and 14 °C for the Surface and Deep consortia, respectively, and crude oil as the sole source of carbon. The Deep consortium was additionally investigated at 25 °C to allow the direct comparison of the degradation rates to the Surface consortium. In total, ~50% of the alkanes and ~15% of the polycyclic aromatic hydrocarbons were degraded in all treatments by Day 24. Approximately ~95% of the total biodegradation by the Deep consortium took place within 6 days regardless of temperature, whereas comparable levels of degradation were reached on Day 12 by the Surface consortium. Both consortia were dominated by well-known hydrocarbon-degrading taxa. Temperature played a significant role in shaping the Deep consortia communities with Pseudomonas and Pseudoalteromonas dominating at 25 °C and Alcanivorax at 14 °C. Overall, the Deep consortium showed a higher efficiency for hydrocarbon degradation within the first week following contamination, which is critical in the case of oil spills, and thus merits further investigation for its exploitation in bioremediation technologies tailored to the Eastern Mediterranean Sea.
Georgia Charalampous; Efsevia Fragkou; Konstantinos Kormas; Alexandre Menezes; Paraskevi Polymenakou; Nikos Pasadakis; Nicolas Kalogerakis; Eleftheria Antoniou; Evangelia Gontikaki. Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential. Energies 2021, 14, 2246 .
AMA StyleGeorgia Charalampous, Efsevia Fragkou, Konstantinos Kormas, Alexandre Menezes, Paraskevi Polymenakou, Nikos Pasadakis, Nicolas Kalogerakis, Eleftheria Antoniou, Evangelia Gontikaki. Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential. Energies. 2021; 14 (8):2246.
Chicago/Turabian StyleGeorgia Charalampous; Efsevia Fragkou; Konstantinos Kormas; Alexandre Menezes; Paraskevi Polymenakou; Nikos Pasadakis; Nicolas Kalogerakis; Eleftheria Antoniou; Evangelia Gontikaki. 2021. "Comparison of Hydrocarbon-Degrading Consortia from Surface and Deep Waters of the Eastern Mediterranean Sea: Characterization and Degradation Potential." Energies 14, no. 8: 2246.
Insect meals are considered promising, eco-friendly, alternative ingredients for aquafeed. Considering the dietary influence on establishment of functioning gut microbiota, the effect of the insect meal diets on the microbial ecology should be addressed. The present study assessed diet- and species-specific shifts in gut resident bacterial communities of juvenile reared Dicentrarchus labrax and Sparus aurata in response to three experimental diets with insect meals from three insects (Hermetia illucens, Tenebrio molitor, Musca domestica), using high-throughput Illumina sequencing of the V3–V4 region of the 16S rRNA gene. The dominant phyla were Firmicutes, Proteobacteria and Actinobacteria in all dietary treatments. Anaerococcus sp., Cutibacterium sp. and Pseudomonas sp. in D. labrax, and Staphylococcus sp., Hafnia sp. and Aeromonas sp. in S. aurata were the most enriched shared species, following insect-meal inclusion. Network analysis of the dietary treatments highlighted diet-induced changes in the microbial community assemblies and revealed unique and shared microbe-to-microbe interactions. PICRUSt-predicted Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were significantly differentiated, including genes associated with metabolic pathways. The present findings strengthen the importance of diet in microbiota configuration and underline that different insects as fish feed ingredients elicit species-specific differential responses of structural and functional dynamics in gut microbial communities.
Nikolas Panteli; Maria Mastoraki; Maria Lazarina; Stavros Chatzifotis; Eleni Mente; Konstantinos Kormas; Efthimia Antonopoulou. Configuration of Gut Microbiota Structure and Potential Functionality in Two Teleosts under the Influence of Dietary Insect Meals. Microorganisms 2021, 9, 699 .
AMA StyleNikolas Panteli, Maria Mastoraki, Maria Lazarina, Stavros Chatzifotis, Eleni Mente, Konstantinos Kormas, Efthimia Antonopoulou. Configuration of Gut Microbiota Structure and Potential Functionality in Two Teleosts under the Influence of Dietary Insect Meals. Microorganisms. 2021; 9 (4):699.
Chicago/Turabian StyleNikolas Panteli; Maria Mastoraki; Maria Lazarina; Stavros Chatzifotis; Eleni Mente; Konstantinos Kormas; Efthimia Antonopoulou. 2021. "Configuration of Gut Microbiota Structure and Potential Functionality in Two Teleosts under the Influence of Dietary Insect Meals." Microorganisms 9, no. 4: 699.
Backgound: The present study investigated the effect of different lipid source in the feed on the colonization and the bacterial succession in early life stages (fertilized eggs until 93 days post first feeding) of S. salar. The two diets used in this study, FD (fish oil based diet) and VD (vegetable oil based diet), were formulated to cover the fish nutritional requirements and except the lipid source the components were identical between them.Hindgut samples collected at 0, 35, 65 and 93 days post first feeding (dpff). Moreover, fertilized eggs, yolk sac larvae, rearing water and feed were also sampled in order to assess a possible contribution of their microbiota to the colonization of the gut. To analyze the composition of the bacterial communities, the Illumina MiSeq platform was used. Results: S. salar growth variables (mean wet weight and total length) did not differ significantly during the experiment (p> 0.05) across replicate tanks and between dietary treatments. The analysis of the 16S rDNA sequencing data revealed a total of 4548 unique OTUs, affiliated in 21 bacterial phyla. Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes were the dominant bacterial phyla. 13 OTUs were shared among all S. salar samples independent of life stage and diet treatment. Similarity percentages analysis (SIMPER) based on Bray–Curtis distance, showed that the average dissimilarity among the groups of the same life stages was 76.0%, whereas the average dissimilarity within groups of the same dietary treatment was 78.5% (FD) and 83.6% (VD). Conclusion: Feeding on either fish oil or vegetable oil-based diets, did not result in significant differences in the intestinal microbiota. The composition of gut microbiota did not differ significantly between the two dietary treatments, but changed with age, and each stage was characterized by different dominant bacteria. These OTUs are related to species that provide different functions and have been isolated from a variety of environments. Finally, this study revealed the occurrence of a core microbiota independent of the studied life stages and diet during the early life stages of Atlantic salmon.
Eleni Nikouli; Konstantinos Kormas; Yang Jin; Yngvar Olsen; Ingrid Bakke; Olav Vadstein. Early life bacterial succession under different diet regime Atlantic salmon (Salmo salar L.). 2020, 1 .
AMA StyleEleni Nikouli, Konstantinos Kormas, Yang Jin, Yngvar Olsen, Ingrid Bakke, Olav Vadstein. Early life bacterial succession under different diet regime Atlantic salmon (Salmo salar L.). . 2020; ():1.
Chicago/Turabian StyleEleni Nikouli; Konstantinos Kormas; Yang Jin; Yngvar Olsen; Ingrid Bakke; Olav Vadstein. 2020. "Early life bacterial succession under different diet regime Atlantic salmon (Salmo salar L.)." , no. : 1.
Backgound: The present study investigated the effect of different lipid source in the feed on the colonization and the bacterial succession in early life stages (fertilized eggs until 93 days post first feeding) of S. salar. The two diets used in this study, FD (fish oil based diet) and VD (vegetable oil based diet), were formulated to cover the fish nutritional requirements and except the lipid source the components were identical between them. Hindgut samples collected at 0, 35, 65 and 93 days post first feeding (dpff). Moreover, fertilized eggs, yolk sac larvae, rearing water and feed were also sampled in order to assess a possible contribution of their microbiota to the colonization of the gut. To analyze the composition of the bacterial communities, the Illumina MiSeq platform was used.Results: S. salar growth variables (mean wet weight and total length) did not differ significantly during the experiment (p> 0.05) across replicate tanks and between dietary treatments. The analysis of the 16S rDNA sequencing data revealed a total of 4548 unique OTUs, affiliated in 21 bacterial phyla. Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes were the dominant bacterial phyla. 13 OTUs were shared among all S. salar samples independent of life stage and diet treatment. Similarity percentages analysis (SIMPER) based on Bray–Curtis distance, showed that the average dissimilarity among the groups of the same life stages was 76.0%, whereas the average dissimilarity within groups of the same dietary treatment was 78.5% (FD) and 83.6% (VD).Conclusion: Feeding on either fish oil or vegetable oil-based diets, did not result in significant differences in the intestinal microbiota. The composition of gut microbiota did not differ significantly between the two dietary treatments, but changed with age, and each stage was characterized by different dominant bacteria. These OTUs are related to species that provide different functions and have been isolated from a variety of environments. Finally, this study revealed the occurrence of a core microbiota independent of the studied life stages and diet during the early life stages of Atlantic salmon.
Eleni Nikouli; Konstantinos Kormas; Yang Jin; Yngvar Olsen; Ingrid Bakke; Olav Vadstein. Early Life Bacterial Succession Under Different Diet Regime Atlantic Salmon (Salmo salar L.). 2020, 1 .
AMA StyleEleni Nikouli, Konstantinos Kormas, Yang Jin, Yngvar Olsen, Ingrid Bakke, Olav Vadstein. Early Life Bacterial Succession Under Different Diet Regime Atlantic Salmon (Salmo salar L.). . 2020; ():1.
Chicago/Turabian StyleEleni Nikouli; Konstantinos Kormas; Yang Jin; Yngvar Olsen; Ingrid Bakke; Olav Vadstein. 2020. "Early Life Bacterial Succession Under Different Diet Regime Atlantic Salmon (Salmo salar L.)." , no. : 1.
Cyanobacterial blooms have become a frequent phenomenon in freshwaters worldwide; they are a widely known indicator of eutrophication and water quality deterioration. Information and knowledge contributing towards the evaluation of the ecological status of freshwaters, particularly since many are used for recreation, drinking water, and aquaculture, is valuable. This Special Issue, entitled “Advancing Knowledge on Cyanobacterial Blooms in Freshwaters”, includes 11 research papers that will focus on the use of complementary approaches, from the most recently developed molecular-based methods to more classical approaches and experimental and mathematical modelling regarding the factors (abiotic and/or biotic) that control the diversity of not only the key bloom-forming cyanobacterial species, but also their interactions with other biota, either in freshwater systems or their adjacent habitats, and their role in preventing and/or promoting cyanobacterial growth and toxin production.
Elisabeth Vardaka; Konstantinos Ar. Kormas. Advancing Knowledge on Cyanobacterial Blooms in Freshwaters. Water 2020, 12, 2583 .
AMA StyleElisabeth Vardaka, Konstantinos Ar. Kormas. Advancing Knowledge on Cyanobacterial Blooms in Freshwaters. Water. 2020; 12 (9):2583.
Chicago/Turabian StyleElisabeth Vardaka; Konstantinos Ar. Kormas. 2020. "Advancing Knowledge on Cyanobacterial Blooms in Freshwaters." Water 12, no. 9: 2583.
In this study, we hypothesized that sympatrically grown farmed fish, i.e. fish which experience similar environmental conditions and nutritionally similar diets, would have more convergent gut microbiota. Using a “common garden” approach, we identified the core microbiota and bacterial community structure differences between five fish species farmed in the same aquaculture site on the west coast of the Aegean Sea, Greece. The investigated individuals were at similar developmental stages and reared in adjacent (< 50 m) aquaculture cages; each cage had 15 kg fish m−3. The diets were nutritionally similar to support optimal growth for each fish species. DNA from the midgut of 3–6 individuals per fish species was extracted and sequenced for the V3–V4 region of the bacterial 16S rRNA. Only 3.9% of the total 181 operational taxonomic units (OTUs) were shared among all fish. Between 5 and 74 OTUs were unique to each fish species. Each of the investigated fish species had a distinct profile of dominant OTUs, i.e. cumulative relative abundance of ≥ 80%. Co-occurrence network analysis for each fish species showed that all networks were strongly dominated by positive correlations between the abundances of their OTUs. However, each fish species had different network characteristics suggesting the differential significance of the OTUs in each of the five fish species midgut. The results of the present study may provide evidence that adult fish farmed in the Mediterranean Sea have a rather divergent and species-specific gut microbiota profile, which are shaped independently of the similar environmental conditions under which they grow.
Eleni Nikouli; Alexandra Meziti; Evangelia Smeti; Efthimia Antonopoulou; Eleni Mente; Konstantinos Ar. Kormas. Gut Microbiota of Five Sympatrically Farmed Marine Fish Species in the Aegean Sea. Microbial Ecology 2020, 81, 460 -470.
AMA StyleEleni Nikouli, Alexandra Meziti, Evangelia Smeti, Efthimia Antonopoulou, Eleni Mente, Konstantinos Ar. Kormas. Gut Microbiota of Five Sympatrically Farmed Marine Fish Species in the Aegean Sea. Microbial Ecology. 2020; 81 (2):460-470.
Chicago/Turabian StyleEleni Nikouli; Alexandra Meziti; Evangelia Smeti; Efthimia Antonopoulou; Eleni Mente; Konstantinos Ar. Kormas. 2020. "Gut Microbiota of Five Sympatrically Farmed Marine Fish Species in the Aegean Sea." Microbial Ecology 81, no. 2: 460-470.
Recent discoveries suggest that the candidate superphyla Patescibacteria and DPANN constitute a large fraction of the phylogenetic diversity of Bacteria and Archaea. Their small genomes and limited coding potential have been hypothesized to be ancestral adaptations to obligate symbiotic lifestyles. To test this hypothesis, we performed cell-cell association, genomic, and phylogenetic analyses on 4,829 individual cells of Bacteria and Archaea from 46 globally distributed surface and subsurface field samples. This confirmed the ubiquity and abundance of Patescibacteria and DPANN in subsurface environments, the small size of their genomes and cells, and the divergence of their gene content from other Bacteria and Archaea. Our analyses suggest that most Patescibacteria and DPANN in the studied subsurface environments do not form specific physical associations with other microorganisms. These data also suggest that their unusual genomic features and prevalent auxotrophies may be a result of minimal cellular energy transduction mechanisms that potentially precede the evolution of respiration, thus relying solely on fermentation for energy conservation.
Jacob P. Beam; Eric D. Becraft; Julia M. Brown; Frederik P Schulz; Jessica K. Jarett; Oliver Bezuidt; Nicole J. Poulton; Kayla Clark; Peter F. Dunfield; Nikolai V. Ravin; John R. Spear; Brian P. Hedlund; Konstantinos A. Kormas; Stefan M. Sievert; Mostafa S. Elshahed; Hazel A. Barton; Matthew B. Stott; Jonathan A. Eisen; Duane P. Moser; Tullis C. Onstott; Tanja Woyke; Ramunas Stepanauskas. Ancestral absence of electron transport chains in Patescibacteria and DPANN. 2020, 1 .
AMA StyleJacob P. Beam, Eric D. Becraft, Julia M. Brown, Frederik P Schulz, Jessica K. Jarett, Oliver Bezuidt, Nicole J. Poulton, Kayla Clark, Peter F. Dunfield, Nikolai V. Ravin, John R. Spear, Brian P. Hedlund, Konstantinos A. Kormas, Stefan M. Sievert, Mostafa S. Elshahed, Hazel A. Barton, Matthew B. Stott, Jonathan A. Eisen, Duane P. Moser, Tullis C. Onstott, Tanja Woyke, Ramunas Stepanauskas. Ancestral absence of electron transport chains in Patescibacteria and DPANN. . 2020; ():1.
Chicago/Turabian StyleJacob P. Beam; Eric D. Becraft; Julia M. Brown; Frederik P Schulz; Jessica K. Jarett; Oliver Bezuidt; Nicole J. Poulton; Kayla Clark; Peter F. Dunfield; Nikolai V. Ravin; John R. Spear; Brian P. Hedlund; Konstantinos A. Kormas; Stefan M. Sievert; Mostafa S. Elshahed; Hazel A. Barton; Matthew B. Stott; Jonathan A. Eisen; Duane P. Moser; Tullis C. Onstott; Tanja Woyke; Ramunas Stepanauskas. 2020. "Ancestral absence of electron transport chains in Patescibacteria and DPANN." , no. : 1.
Mud volcanoes and pockmarks are sites which methane and other gases seep out towards the overlying water. This supply and the microbiologically-mediated processes of these cold seeps can be the basis of unique microbial habitats. Although mud volcanoes and pockmarks vary in the seepage rate and chemical composition of their outflows, the communities found in geographically adjacent systems seem to harbor comparable microbial communities. For the East Mediterranean Sea, only sporadic data exist on its major mud volcanoes and pockmarks collected through a few oceanographic cruises; however, further the knowledge of these systems should be gained by microbiological and sequence-based investigations.
Konstantinos Ar. Kormas; Alexandra Meziti. The Microbial Communities of the East Mediterranean Sea Mud Volcanoes and Pockmarks. Pollution in the Black Sea 2020, 143 -148.
AMA StyleKonstantinos Ar. Kormas, Alexandra Meziti. The Microbial Communities of the East Mediterranean Sea Mud Volcanoes and Pockmarks. Pollution in the Black Sea. 2020; ():143-148.
Chicago/Turabian StyleKonstantinos Ar. Kormas; Alexandra Meziti. 2020. "The Microbial Communities of the East Mediterranean Sea Mud Volcanoes and Pockmarks." Pollution in the Black Sea , no. : 143-148.
In Skiathos Island the water is not potable due to mercury contamination and salinization. The mercury’s origin is natural due to the existence of cinnabar in the Skiathos aquifer as a mineral in the Earth’s crust. The possibility of mercury contaminants ending up in the coastal area was investigated through a field experiment. Mussels (Mytilus galloprovincialis) were employed as mercury monitoring biomarkers at the outflow of the wastewater treatment of the island. Using the RNA:DNA ratio, it was revealed that the organisms were stressed after three months of exposure to Skiathos’ coastal waters. The mercury concentration was directly measured at the bulk mussels’ tissue showing differences between the station located at the outflow of the WWT and the reference station. Although the results may imply mercury contamination in the coastal area of the island, the precise origin of the mercury in mussels is difficult to define.
Alexandra Spyropoulou; Chrysi Laspidou; Kostantinos Kormas; Yannis G. Lazarou. The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island. Environmental Sciences Proceedings 2020, 2, 50 .
AMA StyleAlexandra Spyropoulou, Chrysi Laspidou, Kostantinos Kormas, Yannis G. Lazarou. The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island. Environmental Sciences Proceedings. 2020; 2 (1):50.
Chicago/Turabian StyleAlexandra Spyropoulou; Chrysi Laspidou; Kostantinos Kormas; Yannis G. Lazarou. 2020. "The Impact of Possible Mercury Source-Point Contamination in the Coastal Area of Skiathos Island." Environmental Sciences Proceedings 2, no. 1: 50.
Unicellular eukaryotes have pivotal ecological roles in aquatic ecosystems by participating in biogeochemical processes and structuring microbial food webs. However, revealing their biogeographical patterns remains challenging, as it is reflected in the rather limited available knowledge. In this study, two central patterns, the taxa–area and the distance–decay relationships, were tested for freshwater unicellular eukaryotes. Sampling was performed in 31 mountainous freshwater ecosystems in Thessaly (Greece). Sampling sites had different geohydromorphological characteristics (altitude, 124–704 m; depth, 0.3–1 m; surface area, 188–123 000 m2; geographical distances, 0.03–48.4 km). Unicellular eukaryote diversity was assessed by 18S rRNA gene diversity with high-throughput sequencing. Five supergroups (Stramenopiles, Alveolata, Rhizaria, Archaeplastida and Opisthokonta) were found with the most abundant taxa being Stramenopiles and Alveolata. Aquatic unicellular eukaryotes showed statistically significant but weak DDR and TAR. This can be attributed to the large proportion of specialists (91.9% of operational taxonomic units according to Levin’s index). These results indicate that although mountainous pools and ponds can host high diversity of unicellular eukaryotes, the shaping of their communities is mainly regulated by niche-specific processes and environmental filtering and to a lesser extent by species dispersion processes.
Sofia C Macingo; Konstantinos Kormas; Andreas Oikonomou; Hera Karayanni. Taxa–area and distance–decay relationships of unicellular eukaryotes along an elevation gradient of mountainous freshwater ecosystems. Journal Of Plankton Research 2019, 41, 821 -834.
AMA StyleSofia C Macingo, Konstantinos Kormas, Andreas Oikonomou, Hera Karayanni. Taxa–area and distance–decay relationships of unicellular eukaryotes along an elevation gradient of mountainous freshwater ecosystems. Journal Of Plankton Research. 2019; 41 (6):821-834.
Chicago/Turabian StyleSofia C Macingo; Konstantinos Kormas; Andreas Oikonomou; Hera Karayanni. 2019. "Taxa–area and distance–decay relationships of unicellular eukaryotes along an elevation gradient of mountainous freshwater ecosystems." Journal Of Plankton Research 41, no. 6: 821-834.
The enactment of the Water Framework Directive (WFD) initiated scientific efforts to develop reliable methods for comparing prevailing lake conditions against reference (or nonimpaired) states, using the state of a set biological elements. Drawing a distinction between impaired and natural conditions can be a challenging exercise. Another important aspect is to ensure that water quality assessment is comparable among the different Member States. In this context, the present paper offers a constructive critique of the practices followed during the WFD implementation in Greece by pinpointing methodological weaknesses and knowledge gaps that undermine our ability to classify the ecological quality of Greek lakes. One of the pillars of WDF is a valid lake typology that sets ecological standards transcending geographic regions and national boundaries. The national typology of Greek lakes has failed to take into account essential components. WFD compliance assessments based on the descriptions of phytoplankton communities are oversimplified and as such should be revisited. Exclusion of most chroococcal species from the analysis of cyanobacteria biovolume in Greek lakes/reservoirs and most reservoirs in Spain, Portugal, and Cyprus is not consistent with the distribution of those taxa in lakes. Similarly, the total biovolume reference values and the indices used in classification schemes reflect misunderstandings of WFD core principles. This hampers the comparability of ecological status across Europe and leads to quality standards that are too relaxed to provide an efficient target for the protection of Greek/transboundary lakes such as the ancient Lake Megali Prespa.
Maria Moustaka-Gouni; Ulrich Sommer; Athena Economou-Amilli; George Arhonditsis; Matina Katsiapi; Eva Papastergiadou; Konstantinos Kormas; Elisabeth Vardaka; Hera Karayanni; Theodoti Papadimitriou. Implementation of the Water Framework Directive: Lessons Learned and Future Perspectives for an Ecologically Meaningful Classification Based on Phytoplankton of the Status of Greek Lakes, Mediterranean Region. Environmental Management 2019, 64, 675 -688.
AMA StyleMaria Moustaka-Gouni, Ulrich Sommer, Athena Economou-Amilli, George Arhonditsis, Matina Katsiapi, Eva Papastergiadou, Konstantinos Kormas, Elisabeth Vardaka, Hera Karayanni, Theodoti Papadimitriou. Implementation of the Water Framework Directive: Lessons Learned and Future Perspectives for an Ecologically Meaningful Classification Based on Phytoplankton of the Status of Greek Lakes, Mediterranean Region. Environmental Management. 2019; 64 (6):675-688.
Chicago/Turabian StyleMaria Moustaka-Gouni; Ulrich Sommer; Athena Economou-Amilli; George Arhonditsis; Matina Katsiapi; Eva Papastergiadou; Konstantinos Kormas; Elisabeth Vardaka; Hera Karayanni; Theodoti Papadimitriou. 2019. "Implementation of the Water Framework Directive: Lessons Learned and Future Perspectives for an Ecologically Meaningful Classification Based on Phytoplankton of the Status of Greek Lakes, Mediterranean Region." Environmental Management 64, no. 6: 675-688.
The idea that ‘everything is everywhere, but the environment selects' has been seminal in microbial biogeography, and marine phytoplankton is one of the prototypical groups used to illustrate this. The typical argument has been that phytoplankton is ubiquitous, but that distinct assemblages form under environmental selection. It is well established that phytoplankton assemblages vary considerably between coastal ecosystems. However, the relative roles of compartmentalization of regional seas and site-specific environmental conditions in shaping assemblage structures have not been specifically examined. We collected data from coastal embayments that fall within two different water compartments within the same regional sea and are characterized by highly localized environmental pressures. We used principal coordinates of neighbour matrices (PCNM) and asymmetric eigenvector maps (AEM) models to partition the effects that spatial structures, environmental conditions and their overlap had on the variation in assemblage composition. Our models explained a high percentage of variation in assemblage composition (59–65%) and showed that spatial structure consistent with marine compartmentalization played a more important role than local environmental conditions. At least during the study period, surface currents connecting sites within the two compartments failed to generate sufficient dispersal to offset the impact of differences due to compartmentalization. In other words, our findings suggest that, even for a prototypical cosmopolitan group, everything is not everywhere.
Sofie Spatharis; Vasiliki Lamprinou; Alexandra Meziti; Konstantinos Kormas; Daniel D. Danielidis; Evangelia Smeti; Daniel L. Roelke; Rebecca Mancy; George Tsirtsis. Everything is not everywhere: can marine compartments shape phytoplankton assemblages? Proceedings of the Royal Society B: Biological Sciences 2019, 286, 20191890 .
AMA StyleSofie Spatharis, Vasiliki Lamprinou, Alexandra Meziti, Konstantinos Kormas, Daniel D. Danielidis, Evangelia Smeti, Daniel L. Roelke, Rebecca Mancy, George Tsirtsis. Everything is not everywhere: can marine compartments shape phytoplankton assemblages? Proceedings of the Royal Society B: Biological Sciences. 2019; 286 (1914):20191890.
Chicago/Turabian StyleSofie Spatharis; Vasiliki Lamprinou; Alexandra Meziti; Konstantinos Kormas; Daniel D. Danielidis; Evangelia Smeti; Daniel L. Roelke; Rebecca Mancy; George Tsirtsis. 2019. "Everything is not everywhere: can marine compartments shape phytoplankton assemblages?" Proceedings of the Royal Society B: Biological Sciences 286, no. 1914: 20191890.
Bacterial and archaeal diversity and succession were studied during a mesocosm experiment that investigated whether changing light regimes could affect the onset of phytoplankton blooms. For this, 454-pyrosequencing of the bacterial V1-V3 and archaeal V3-V9 16S rRNA regions was performed in samples collected from four mesocosms receiving different light irradiances at the beginning and the end of the experiment and during phytoplankton growth. In total, 46 bacterial operational taxonomic units (OTUs) with ≥1% relative abundance occurred (22–34 OTUs per mesocosm). OTUs were affiliated mainly with Rhodobacteraceae, Flavobacteriaceae and Alteromonadaceae. The four mesocosms shared 11 abundant OTUs. Dominance increased at the beginning of phytoplankton growth in all treatments and decreased thereafter. Maximum dominance was found in the mesocosms with high irradiances. Overall, specific bacterial OTUs had different responses in terms of relative abundance under in situ and high light intensities, and an early phytoplankton bloom resulted in different bacterial community structures both at high (family) and low (OTU) taxonomic levels. Thus, bacterial community structure and succession are affected by light regime, both directly and indirectly, which may have implications for an ecosystem’s response to environmental changes.
Hera Karayanni; Konstantinos A. Kormas; Maria Moustaka-Gouni; Ulrich Sommer; Moustaka- Gouni. Changes in Heterotrophic Picoplankton Community Structure after Induction of a Phytoplankton Bloom under Different Light Regimes. Diversity 2019, 11, 195 .
AMA StyleHera Karayanni, Konstantinos A. Kormas, Maria Moustaka-Gouni, Ulrich Sommer, Moustaka- Gouni. Changes in Heterotrophic Picoplankton Community Structure after Induction of a Phytoplankton Bloom under Different Light Regimes. Diversity. 2019; 11 (10):195.
Chicago/Turabian StyleHera Karayanni; Konstantinos A. Kormas; Maria Moustaka-Gouni; Ulrich Sommer; Moustaka- Gouni. 2019. "Changes in Heterotrophic Picoplankton Community Structure after Induction of a Phytoplankton Bloom under Different Light Regimes." Diversity 11, no. 10: 195.
Since the introduction of the term holobiont [...].
Konstantinos Ar. Kormas. Editorial for the Special Issue: Gut Microorganisms of Aquatic Animals. Microorganisms 2019, 7, 377 .
AMA StyleKonstantinos Ar. Kormas. Editorial for the Special Issue: Gut Microorganisms of Aquatic Animals. Microorganisms. 2019; 7 (10):377.
Chicago/Turabian StyleKonstantinos Ar. Kormas. 2019. "Editorial for the Special Issue: Gut Microorganisms of Aquatic Animals." Microorganisms 7, no. 10: 377.
Brackish aquaponics using Mediterranean fish and plants provides an alternative opportunity for a combined production of high-quality food products with high commercial and nutritional value. This is the first study that investigates the effect of two different salinities (8 and 20 ppt) on growth and survival of Sparus aurata and Crithmum maritimum along with the cellular stress pathways using the activation of heat shock proteins (HSPs) and mitogen-activated protein kinase (MAPK) protein family members and the water bacterial abundance. In total, 156 fish were used (average initial weight of 2.55 g, length of 5.57 cm) and 36 plants (average initial height of 8.23 cm) in floating racks above the 135 L fish tanks. Survival rate for both organisms was 100%. C. crithmum grew better at 8 ppt (t-test, p < 0.05). The growth rate of S. aurata was similar for both treatments (p > 0.05). HSPs and MAPK were differentially expressed, showing tissue-specific responses. The average bacterial abundance at the end of the experiment was higher (p < 0.05) in the 20 ppt (18.6 ± 0.91 cells × 105/mL) compared to the 8 ppt (6.8 ± 1.9 cells × 105/mL). The results suggest that the combined culture of euryhaline fish and halophytes provides good quality products in brackish aquaponics systems.
Nikolaos Vlahos; Efi Levizou; Paraskevi Stathopoulou; Panagiotis Berillis; Efthimia Antonopoulou; Vlasoula Bekiari; Nikos Krigas; Konstantinos Kormas; Eleni Mente. An Experimental Brackish Aquaponic System Using Juvenile Gilthead Sea Bream (Sparus aurata) and Rock Samphire (Crithmum maritimum). Sustainability 2019, 11, 4820 .
AMA StyleNikolaos Vlahos, Efi Levizou, Paraskevi Stathopoulou, Panagiotis Berillis, Efthimia Antonopoulou, Vlasoula Bekiari, Nikos Krigas, Konstantinos Kormas, Eleni Mente. An Experimental Brackish Aquaponic System Using Juvenile Gilthead Sea Bream (Sparus aurata) and Rock Samphire (Crithmum maritimum). Sustainability. 2019; 11 (18):4820.
Chicago/Turabian StyleNikolaos Vlahos; Efi Levizou; Paraskevi Stathopoulou; Panagiotis Berillis; Efthimia Antonopoulou; Vlasoula Bekiari; Nikos Krigas; Konstantinos Kormas; Eleni Mente. 2019. "An Experimental Brackish Aquaponic System Using Juvenile Gilthead Sea Bream (Sparus aurata) and Rock Samphire (Crithmum maritimum)." Sustainability 11, no. 18: 4820.
One of the most widely reared fish in the Mediterranean Sea is Sparus aurata. The succession of S. aurata whole-body microbiota in fertilized eggs, five, 15, 21 and 71 days post hatch (dph) larvae and the contribution of the rearing water and the provided feed (rotifers, Artemia sp. and commercial diet) to the host’s microbiota was investigated by 454 pyrosequencing of the 16S rRNA gene diversity. In total, 1917 bacterial operational taxonomic units (OTUs) were found in all samples. On average, between 93 ± 2.1 and 366 ± 9.2 bacterial OTUs per sample were found, with most of them belonging to Proteobacteria and Bacteroidetes. Ten OTUs were shared between all S. aurata stages and were also detected in the rearing water or diet. The highest OTU richness occurred at the egg stage and the lowest at the yolk sac stage (5 dph). The rearing water and diet microbial communities contributed in S. aurata microbiota without overlaps in their microbial composition and structure. The commercial diet showed higher contribution to the S. aurata microbiota than the rearing water. After stage D71 the observed microbiota showed similarities with that of adult S. aurata as indicated by the increased number of OTUs associated with γ-Proteobacteria and Firmicutes.
Eleni Nikouli; Alexandra Meziti; Efthimia Antonopoulou; Eleni Mente; Konstantinos Ar. Kormas. Host-Associated Bacterial Succession during the Early Embryonic Stages and First Feeding in Farmed Gilthead Sea Bream (Sparus aurata). Genes 2019, 10, 483 .
AMA StyleEleni Nikouli, Alexandra Meziti, Efthimia Antonopoulou, Eleni Mente, Konstantinos Ar. Kormas. Host-Associated Bacterial Succession during the Early Embryonic Stages and First Feeding in Farmed Gilthead Sea Bream (Sparus aurata). Genes. 2019; 10 (7):483.
Chicago/Turabian StyleEleni Nikouli; Alexandra Meziti; Efthimia Antonopoulou; Eleni Mente; Konstantinos Ar. Kormas. 2019. "Host-Associated Bacterial Succession during the Early Embryonic Stages and First Feeding in Farmed Gilthead Sea Bream (Sparus aurata)." Genes 10, no. 7: 483.
The aquaculture industry is currently looking for alternative, sustainable diets that provide similar or better growth for the reared species. We investigated whether replacing fishmeal with yellow mealworm (Tenebrio molitor) meal in the supplied diets of the gilthead sea bream (Sparus aurata), European sea bass (Dicentrarchus labrax) and rainbow trout (Oncorhynchus mykiss) causes similar shifts in the bacterial gut communities of these farmed fish species. The diversity of the gut bacterial 16S rRNA gene revealed the presence of 598 operational taxonomic units (OTUs) belonging to all of the major phyla known to exist in the gut of these three fish species, such as Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria. Although no statistically significant differences of diversity indices in all three species was found, there was a differential shift in the dominant bacteria in the gut of each species before and after the dietary meal replacement. In S. aurata and D. labrax diversity indices remained practically unchanged before and after the replacement, while for O. mykiss the five-fold increase of the Simpson dominance D index and the almost two-fold decrease of the Shannon H index, suggested that a more specialized gut bacterial community was favoured for this species after the replacement. Also, this replacement resulted in the occurrence of higher number of OTUs which were absent before the replacement in the gut of S. aurata (62.2% of all its OTUs) and D. labrax (60.0% of all its OTUs) compared to O. mykiss (33.0% of all its OTUs) suggesting that insect meal replacement resulted in novel nutritional niches in the gut of S. aurata and D. labrax compared to O. mykiss. Our results indicate that the most desirable fish diet substitution differentially affects the gut microbiota in different hosts, implying that a species-specific tailor-made approach in diet manipulations should be considered in the future.
Efthimia Antonopoulou; Eleni Nikouli; Giovanni Piccolo; Laura Gasco; Francesco Gai; Stavros Chatzifotis; Eleni Mente; Konstantinos Ar Kormas. Reshaping gut bacterial communities after dietary Tenebrio molitor larvae meal supplementation in three fish species. Aquaculture 2018, 503, 628 -635.
AMA StyleEfthimia Antonopoulou, Eleni Nikouli, Giovanni Piccolo, Laura Gasco, Francesco Gai, Stavros Chatzifotis, Eleni Mente, Konstantinos Ar Kormas. Reshaping gut bacterial communities after dietary Tenebrio molitor larvae meal supplementation in three fish species. Aquaculture. 2018; 503 ():628-635.
Chicago/Turabian StyleEfthimia Antonopoulou; Eleni Nikouli; Giovanni Piccolo; Laura Gasco; Francesco Gai; Stavros Chatzifotis; Eleni Mente; Konstantinos Ar Kormas. 2018. "Reshaping gut bacterial communities after dietary Tenebrio molitor larvae meal supplementation in three fish species." Aquaculture 503, no. : 628-635.
Recent diversity studies have revealed that microbial communities of natural environments are dominated by species-like, sequence-discrete populations. However, how stable the sequence and gene-content diversity are within these populations and especially in highly dynamic lotic habitats remain unclear. Here we quantified the dynamics of intra-population diversity in samples spanning two years and five sites in the Kalamas River (Northwest Greece). A significant positive correlation was observed between higher intra-population sequence diversity and longer persistence over time, revealing that more diverse populations tended to represent more autochthonous (vs. allochthonous) community members. Assessment of intra-population gene-content changes caused by strain replacement or gene loss over time revealed different profiles with the majority of populations exhibiting gene-content changes close to 10% of the total genes, while one population exhibited ~21% change. The variable genes were enriched in hypothetical proteins and mobile elements, and thus, were probably functionally neutral or attributable to phage predation. A few notable exceptions to this pattern were also noted such as phototrophy-related proteins in summer vs. winter populations. Taken together, these results revealed that some freshwater genomes are remarkably dynamic, even across short time and spatial scales, and have implications for the bacterial species concept and microbial source tracking.
Alexandra Meziti; Despina Tsementzi; Luis M. Rodriguez-R; Janet K. Hatt; Hera Karayanni; Konstantinos A. Kormas; Konstantinos T. Konstantinidis. Quantifying the changes in genetic diversity within sequence-discrete bacterial populations across a spatial and temporal riverine gradient. The ISME Journal 2018, 13, 767 -779.
AMA StyleAlexandra Meziti, Despina Tsementzi, Luis M. Rodriguez-R, Janet K. Hatt, Hera Karayanni, Konstantinos A. Kormas, Konstantinos T. Konstantinidis. Quantifying the changes in genetic diversity within sequence-discrete bacterial populations across a spatial and temporal riverine gradient. The ISME Journal. 2018; 13 (3):767-779.
Chicago/Turabian StyleAlexandra Meziti; Despina Tsementzi; Luis M. Rodriguez-R; Janet K. Hatt; Hera Karayanni; Konstantinos A. Kormas; Konstantinos T. Konstantinidis. 2018. "Quantifying the changes in genetic diversity within sequence-discrete bacterial populations across a spatial and temporal riverine gradient." The ISME Journal 13, no. 3: 767-779.
This study investigated the profile of the autochthonous gut bacterial communities in adult individuals of Sparus aurata and Dicentrarchus labrax reared in sea cages in five distantly located aquaculture farms in Greece and determine the impact of geographic location on them in order to detect the core gut microbiota of these commercially important fish species. Data analyses resulted in no significant geographic impact in the gut microbial communities within the two host species, while strong similarities between them were also present. Our survey revealed the existence of a core gut microbiota within and between the two host species independent of diet and geographic location consisting of the Delftia, Pseudomonas, Pelomonas, Propionibacterium, and Atopostipes genera.
Eleni Nikouli; Alexandra Meziti; Efthimia Antonopoulou; Eleni Mente; Konstantinos A. Kormas. Gut Bacterial Communities in Geographically Distant Populations of Farmed Sea Bream (Sparus aurata) and Sea Bass (Dicentrarchus labrax). Microorganisms 2018, 6, 92 .
AMA StyleEleni Nikouli, Alexandra Meziti, Efthimia Antonopoulou, Eleni Mente, Konstantinos A. Kormas. Gut Bacterial Communities in Geographically Distant Populations of Farmed Sea Bream (Sparus aurata) and Sea Bass (Dicentrarchus labrax). Microorganisms. 2018; 6 (3):92.
Chicago/Turabian StyleEleni Nikouli; Alexandra Meziti; Efthimia Antonopoulou; Eleni Mente; Konstantinos A. Kormas. 2018. "Gut Bacterial Communities in Geographically Distant Populations of Farmed Sea Bream (Sparus aurata) and Sea Bass (Dicentrarchus labrax)." Microorganisms 6, no. 3: 92.