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1.
Sci Rep ; 12(1): 121, 2022 01 07.
Artículo en Inglés | MEDLINE | ID: mdl-34996900

RESUMEN

Herein, the effect of dietary inclusion of insect (Tenebrio molitor) meal on hepatic pathways of apoptosis and autophagy in three farmed fish species, gilthead seabream (Sparus aurata), European seabass (Dicentrarchus labrax) and rainbow trout (Oncorhynchus mykiss), fed diets at 25%, 50% and 60% insect meal inclusion levels respectively, was investigated. Hepatic proteome was examined by liver protein profiles from the three fish species, obtained by two-dimensional gel electrophoresis. Although cellular stress was evident in the three teleost species following insect meal, inclusion by T. molitor, D. labrax and O. mykiss suppressed apoptosis through induction of hepatic autophagy, while in S. aurata both cellular procedures were activated. Protein abundance showed that a total of 30, 81 and 74 spots were altered significantly in seabream, European seabass and rainbow trout, respectively. Insect meal inclusion resulted in individual protein abundance changes, with less number of proteins altered in gilthead seabream compared to European seabass and rainbow trout. This is the first study demonstrating that insect meal in fish diets is causing changes in liver protein abundances. However, a species-specific response both in the above mentioned bioindicators, indicates the need to strategically manage fish meal replacement in fish diets per species.


Asunto(s)
Alimentación Animal , Apoptosis , Autofagia , Insectos Comestibles/embriología , Proteínas de Peces/metabolismo , Explotaciones Pesqueras , Peces/metabolismo , Hígado/metabolismo , Proteoma , Tenebrio/embriología , Animales , Lubina/metabolismo , Larva , Valor Nutritivo , Oncorhynchus mykiss/metabolismo , Proteómica , Dorada/metabolismo , Especificidad de la Especie
2.
Microorganisms ; 9(4)2021 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-33800578

RESUMEN

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.

3.
Microb Ecol ; 81(2): 460-470, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32840670

RESUMEN

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.


Asunto(s)
Explotaciones Pesqueras , Peces/microbiología , Microbioma Gastrointestinal , Animales , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Dieta/veterinaria , Peces/clasificación , Peces/crecimiento & desarrollo , Grecia , Mar Mediterráneo , ARN Ribosómico 16S , Especificidad de la Especie
4.
Microorganisms ; 7(10)2019 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-31546574

RESUMEN

Since the introduction of the term holobiont [...].

5.
Genes (Basel) ; 10(7)2019 06 26.
Artículo en Inglés | MEDLINE | ID: mdl-31247994

RESUMEN

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.


Asunto(s)
Bacterias/clasificación , Microbiota/genética , Dorada/microbiología , Alimentación Animal , Animales , Artemia/genética , Bacterias/genética , Bacterias/aislamiento & purificación , Bacteroidetes/genética , Dieta , Firmicutes/genética , Explotaciones Pesqueras , Larva/microbiología , Mar Mediterráneo , Proteobacteria/genética , ARN Ribosómico 16S/genética , Rotíferos/genética , Dorada/embriología , Dorada/crecimiento & desarrollo , Alimentos Marinos/microbiología , Cigoto/microbiología
6.
AIMS Microbiol ; 4(3): 397-412, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-31294223

RESUMEN

Chitinolytic bacteria are widespread in marine and terrestrial environment, and this is rather a reflection of their principle growth substrate's ubiquity, chitin, in our planet. In this paper, we investigated the development of naturally occurring bacterial biofilms on the exoskeleton of the shrimp Melicertus kerathurus during its degradation in sea water. During a 12-day experiment with exoskeleton fragments in batch cultures containing only sea water as the growth medium at 18 °C in darkness, we analysed the formation and succession of biofilms by scanning electron microscopy and 16S rRNA gene diversity by next generation sequencing. Bacteria belonging to the γ- and α-Proteobacteria and Bacteroidetes showed marked (less or more than 10%) changes in their relative abundance from the beginning of the experiment. These bacterial taxa related to known chitinolytic bacteria were the Pseudolateromonas porphyrae, Halomonas aquamarina, Reinekea aestuarii, Colwellia asteriadis and Vibrio crassostreae. These bacteria could be considered as appropriate candidates for the degradation of chitinous crustacean waste from the seafood industry as they dominated in the biofilms developed on the shrimp's exoskeleton in natural sea water with no added substrates and the degradation of the shrimp exoskeleton was also evidenced.

7.
Ecotoxicol Environ Saf ; 143: 193-200, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28550806

RESUMEN

This study investigated the microcystins (MCs)-rich irrigation water effect on lettuce of different developmental stages, i.e. during a two months period, covering the whole period from seed germination to harvest at marketable size of the plant. We followed four lettuce plant groups receiving MCs-rich water (1.81µgl-1 of dissolved MCs), originating from the Karla Reservoir, central Greece: 1) from seeds, 2) the cotyledon, 3) two true leaves and 4) four true leaves stages, all of which were compared to control plants that received tap water. Lettuce growth, photosynthetic performance, biochemical and mineral characteristics, as well as MCs accumulation in leaves, roots and soil were measured. The overall performance of lettuce at various developmental stages pointed to increased tolerance since growth showed minor alterations and non-enzymatic antioxidants remained unaffected. Plants receiving MCs-rich water from the seed stage exhibited higher photosynthetic capacity, chlorophylls and leaf nitrogen content. Nevertheless, considerable MCs accumulation in various plant tissues occurred. The earlier in their development lettuce plants started receiving MCs-rich water, the more MCs they accumulated: roots and leaves of plants exposed to MCs-rich water from seeds and cotyledons stage exhibited doubled MCs concentrations compared to respective tissues of the 4 Leaves group. Furthermore, roots accumulated significantly higher MCs amounts than leaves of the same plant group. Concerning human health risk, the Estimated Daily Intake values (EDI) of Seed and Cotyledon groups leaves exceeded Tolerable Daily Intake (TDI) by a factor of 6, while 2 Leaves and 4 Leaves groups exceeded TDI by a factor of 4.4 and 2.4 respectively. Our results indicate that irrigation of lettuce with MCs-rich water may constitute a serious public health risk, especially when contaminated water is received from the very early developmental stages (seed and cotyledon). Finally, results obtained for the tolerant lettuce indicate that MCs bioaccumulation in edible tissues is not necessarily coupled with phytotoxic effects.


Asunto(s)
Lechuga/efectos de los fármacos , Microcistinas/farmacocinética , Microcistinas/toxicidad , Contaminantes Químicos del Agua/farmacocinética , Contaminantes Químicos del Agua/toxicidad , Riego Agrícola , Grecia , Humanos , Lechuga/crecimiento & desarrollo , Lechuga/metabolismo , Fotosíntesis/efectos de los fármacos , Hojas de la Planta/efectos de los fármacos , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Medición de Riesgo
8.
PeerJ ; 4: e1829, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27069786

RESUMEN

Mussel biofiltration is a widely used approach for the mitigation of aquaculture water. In this study, we investigated the effect of mussel biofiltration on the communities of particle-associated bacteria and unicellular eukaryotes in a sea bass aquaculture in southern North Sea. We assessed the planktonic community changes before and after biofiltration based on the diversity of the 16S and 18S rRNA genes by using next generation sequencing technologies. Although there was no overall reduction in the operational taxonomic units (OTU) numbers between the control (no mussels) and the test (with mussels) tanks, a clear reduction in the relative abundance of the top three most dominant OTUs in every sampling time was observed, ranging between 2-28% and 16-82% for Bacteria and Eukarya, respectively. The bacterial community was dominated by OTUs related to phytoplankton blooms and/or high concentrations of detritus. Among the eukaryotes, several fungal and parasitic groups were found. Their relative abundance in most cases was also reduced from the control to the test tanks; a similar decreasing pattern was also observed for both major higher taxa and functional (trophic) groups. Overall, this study showed the effectiveness of mussel biofiltration on the decrease of microbiota abundance and diversity in seawater fueling fish farms.

9.
BMC Biol ; 13: 105, 2015 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-26652623

RESUMEN

BACKGROUND: The deep-sea hypersaline anoxic basins (DHABs) of the Mediterranean (water depth ~3500 m) are some of the most extreme oceanic habitats known. Brines of DHABs are nearly saturated with salt, leading many to suspect they are uninhabitable for eukaryotes. While diverse bacterial and protistan communities are reported from some DHAB haloclines and brines, loriciferans are the only metazoan reported to inhabit the anoxic DHAB brines. Our goal was to further investigate metazoan communities in DHAB haloclines and brines. RESULTS: We report observations from sediments of three DHAB (Urania, Discovery, L'Atalante) haloclines, comparing these to observations from sediments underlying normoxic waters of typical Mediterranean salinity. Due to technical difficulties, sampling of the brines was not possible. Morphotype analysis indicates nematodes are the most abundant taxon; crustaceans, loriciferans and bryozoans were also noted. Among nematodes, Daptonema was the most abundant genus; three morphotypes were noted with a degree of endemicity. The majority of rRNA sequences were from planktonic taxa, suggesting that at least some individual metazoans were preserved and inactive. Nematode abundance data, in some cases determined from direct counts of sediments incubated in situ with CellTracker(TM) Green, was patchy but generally indicates the highest abundances in either normoxic control samples or in upper halocline samples; nematodes were absent or very rare in lower halocline samples. Ultrastructural analysis indicates the nematodes in L'Atalante normoxic control sediments were fit, while specimens from L'Atalante upper halocline were healthy or had only recently died and those from the lower halocline had no identifiable organelles. Loriciferans, which were only rarely encountered, were found in both normoxic control samples as well as in Discovery and L'Atalante haloclines. It is not clear how a metazoan taxon could remain viable under this wide range of conditions. CONCLUSIONS: We document a community of living nematodes in normoxic, normal saline deep-sea Mediterranean sediments and in the upper halocline portions of the DHABs. Occurrences of nematodes in mid-halocline and lower halocline samples did not provide compelling evidence of a living community in those zones. The possibility of a viable metazoan community in brines of DHABs is not supported by our data at this time.


Asunto(s)
Distribución Animal , Biodiversidad , Sedimentos Geológicos/química , Invertebrados/fisiología , Anaerobiosis , Animales , Invertebrados/clasificación , Mar Mediterráneo , Oxidación-Reducción , ARN Ribosómico/análisis , Salinidad , Análisis de Secuencia de ADN
10.
J Sci Food Agric ; 95(12): 2386-94, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25312872

RESUMEN

BACKGROUND: Sea bream fillets are one of the most important value-added products of the seafood market. Fresh seafood spoils mainly owing to bacterial action. In this study an exploration of initial and spoilage microbiota of sea bream fillets stored under air and commercial modified atmosphere packaging (MAP) at 0 and 5 °C was conducted by 16S rRNA gene sequence analysis of isolates grown on plates. Sensory evaluation and enumeration of total viable counts and spoilage microorganisms were also conducted to determine shelf life and bacterial growth respectively. RESULTS: Different temperatures and atmospheres affected growth and synthesis of spoilage microbiota as well as shelf life. Shelf life under air at 0 and 5 °C was 14 and 5 days respectively, while under MAP it was 20 and 8 days respectively. Initial microbiota were dominated by Pseudomonas fluorescens, Psychrobacter and Macrococcus caseolyticus. Different temperatures and atmospheres affected the synthesis of spoilage microbiota. At the end of shelf life, different phylotypes of Pseudomonas closely related to Pseudomonas fragi were found to dominate in most cases, while Pseudomonas veronii dominated in fillets under MAP at 0 °C. Furthermore, in fillets under MAP at 5 °C, new dominant species such as Carnobacterium maltaromaticum, Carnobacterium divergens and Vagococcus fluvialis were revealed. CONCLUSION: Different temperature and atmospheric conditions affected bacterial growth, shelf life and the synthesis of spoilage microbiota. Molecular identification revealed species and strains of microorganisms that have not been reported before for sea bream fillets stored under various conditions, thus providing valuable information regarding microbiological spoilage.


Asunto(s)
Productos Pesqueros/microbiología , Microbiología de Alimentos , Conservación de Alimentos , Dorada , Animales , Bacterias/genética , Bacterias/aislamiento & purificación , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Humanos , Filogenia , ARN Ribosómico 16S/genética , Temperatura
11.
Sci Total Environ ; 478: 70-9, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24530586

RESUMEN

The molecular diversity of air-dispersed protists was examined through the 18S rRNA gene clone library construction in air samples and samples from experimental water containers passively collecting air-dispersed microorganisms, from July 2007 till October 2008 in three different sites of Northern Greece. The majority of the samplings took place in an urban industrialized coastal city (Thessaloniki). In all the samples, a total of 29 unique phylotypes were detected belonging to 10 known major taxonomic groups. The most abundant phylotypes were affiliated to known taxa of Ciliophora and Chlorophyceae, commonly found in various habitats. Additionally, various previously unnoticed and under-studied taxa, such as Bicosoecida, Oomycetes and Labyrinthulomycetes, were detected. These taxa are potentially important in ecological processes, through dispersal and colonization of various habitats. Multivariate statistical analysis associated the most abundant phylotypes with rainfall, suggesting that rain is a favorable means for reposition of air-dispersed protists. This is the first study investigating the molecular diversity of air-dispersed protists, including algae and heterotrophic protists.


Asunto(s)
Ecosistema , Eucariontes/clasificación , Variación Genética , Biodiversidad , Cilióforos , Biblioteca de Genes , Región Mediterránea , Filogenia
12.
Biomed Res Int ; 2013: 463894, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23841072

RESUMEN

Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA and mlrA (microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of the Methylobacillus and Paucibacter genera. Other strains belonged to the genera Arthrobacter, Bacillus, and Lactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.


Asunto(s)
Bacterias/genética , Toxinas Bacterianas/genética , Cianobacterias/genética , Toxinas Marinas/genética , Microcistinas/genética , ARN Ribosómico 16S/genética , Bacterias/clasificación , Bacterias/crecimiento & desarrollo , Toxinas Bacterianas/metabolismo , Biodegradación Ambiental , Cianobacterias/crecimiento & desarrollo , Cianobacterias/patogenicidad , Ecosistema , Eutrofización , Humanos , Toxinas Marinas/metabolismo , Microcistinas/metabolismo , Filogenia
13.
Springerplus ; 2(1): 66, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23519098

RESUMEN

We analysed the 16S rRNA gene diversity within the bacterioplankton community in the water column of the ornamental fish Pterophyllum scalare and Archocentrus nigrofasciatus aquaria during a 60-day growth experiment in order to detect any dominant bacterial species and their possible association with the rearing organisms. The basic physical and chemical parameters remained stable but the bacterial community at 0, 30 and 60 days showed marked differences in bacterial cell abundance and diversity. We found high species richness but no dominant phylotypes were detected. Only few of the phylotypes were found in more than one time point per treatment and always with low relative abundance. The majority of the common phylotypes belonged to the Proteobacteria phylum and were closely related to Acinetobacter junii, Pseudomonas sp., Nevskia ramosa, Vogesella perlucida, Chitinomonas taiwanensis, Acidovorax sp., Pelomonas saccharophila and the rest belonged to the α-Proteobacteria, Bacteroidetes, Actinobacteria, candidate division OP11 and one unaffiliated group. Several of these phylotypes were closely related to known taxa including Sphingopyxis chilensis, Flexibacter aurantiacus subsp. excathedrus and Mycobacterium sp. Despite the high phylogenetic diversity most of the inferred ecophysiological roles of the found phylotypes are related to nitrogen metabolism, a key process for fish aquaria.

14.
Syst Appl Microbiol ; 35(7): 473-82, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23040460

RESUMEN

The impact of different diets on the gut microbiota of reared Nephrops norvegicus was investigated based on bacterial 16S rRNA gene diversity. Specimens were collected from Pagasitikos Gulf (Greece) and kept in experimental rearing tanks, under in situ conditions, for 6months. Treatments included three diets: frozen natural (mussel) food (M), dry formulated pellet (P) and starvation (S). Gut samples were collected at the initiation of the experiment, and after 3 and 6months. Tank water and diet samples were also analyzed for bacterial 16S rRNA gene diversity. Statistical analysis separated the two groups fed or starved (M and P vs. S samples). Most gut bacteria were not related to the water or diet bacteria, while bacterial diversity was higher in the starvation samples. M and P samples were dominated by Gammaproteobacteria, Epsilonproteobacteria and Tenericutes. Phylotypes clustering in Photobacterium leiognathi, Shewanella sp. and Entomoplasmatales had high frequencies in the M and P samples but low sequence frequencies in S samples. The study showed that feeding resulted in the selection of specific species, which also occurs in the natural population, and might be associated with the animal's nutrition.


Asunto(s)
Bacterias/clasificación , Bacterias/genética , Biodiversidad , Nephropidae/microbiología , Animales , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Dieta , Tracto Gastrointestinal/microbiología , Grecia , Datos de Secuencia Molecular , Nephropidae/fisiología , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
15.
ScientificWorldJournal ; 2012: 504135, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22654619

RESUMEN

Lake Karla, Greece, was dried up in 1962 and its refilling started in 2009. We examined the Cyanobacteria and unicellular eukaryotes found during two fish kill incidents, in March and April 2010, in order to detect possible causative agents. Both microscopic and molecular (16S/18S rRNA gene diversity) identification were applied. Potentially toxic Cyanobacteria included representatives of the Planktothrix and Anabaena groups. Known toxic eukaryotes or parasites related to fish kill events were Prymnesium parvum and Pfiesteria cf. piscicida, the latter being reported in an inland lake for the second time. Other potentially harmful microorganisms, for fish and other aquatic life, included representatives of Fungi, Mesomycetozoa, Alveolata, and Heterokontophyta (stramenopiles). In addition, Euglenophyta, Chlorophyta, and diatoms were represented by species indicative of hypertrophic conditions. The pioneers of L. Karla's plankton during the first months of its water refilling process included species that could cause the two observed fish kill events.


Asunto(s)
Enfermedades de los Peces/microbiología , Peces/microbiología , Plancton/patogenicidad , Anabaena/patogenicidad , Animales , Cianobacterias/patogenicidad , Grecia , Lagos , Pfiesteria piscicida/patogenicidad
16.
Microbes Environ ; 27(4): 504-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22504432

RESUMEN

Studies in the center and margin of the Medee Basin, a Mediterranean deep-sea hypersaline anoxic basin, and at a reference site during Penelope cruise (2007), revealed the existence of a 7 m-thick halocline, with high salinity (328 psu), and high sedimentary organic carbon and biopolymer concentrations. The 194 16S rRNA sequences retrieved were grouped into 118 unique phylotypes. Pseudomonas gessardii, dominated in the center, while 33 phylotypes were detected at the margin and 73 at the reference site. The study suggested conditions hostile to bacteria in the sediments of the Medee Basin and preservation of sedimentary labile organic matter.


Asunto(s)
Bacterias , Sedimentos Geológicos/microbiología , Agua de Mar/microbiología , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Secuencia de Bases , Biodiversidad , ADN Ribosómico/genética , Ecosistema , Mar Mediterráneo , Datos de Secuencia Molecular , Pseudomonas/clasificación , Pseudomonas/genética , Pseudomonas/aislamiento & purificación , ARN Ribosómico 16S/genética , Salinidad , Alineación de Secuencia , Análisis de Secuencia de ADN , Microbiología del Agua
17.
Microbes Environ ; 27(1): 1-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-21971081

RESUMEN

The structure of the Bacteria and Archaea community in a large drinking water reservoir (Marathonas, Greece; MR) was investigated in October 2007 and September 2008, using 16S rRNA gene clone libraries. The bacterial communities were more diverse than archaeal communities (Shannon diversity index H' 0.81-3.28 and 1.36-1.77, respectively). The overall bacterial community composition was comparable to bacterioplankton community described in other freshwater habitats. Within the Bacteria, Betaproteobacteria dominated, while representatives of Alpha-, Gamma- and Deltaproteobacteria also occurred. Other important phyla were Actinobacteria and Bacteroidetes, while representatives of Acidobacteria, Cyanobacteria, Chloroflexi, Planctomycetes and Verrucomicrobia were also retrieved. Several phylotypes in Alpha- and Betaproteobacteria and Bacteroidetes were related to bacteria capable of cyanotoxin degradation and with aromatic compounds/iron oxidizers or polymer degraders. Euryarchaeota dominated (60.5%) the Archaea community mostly with phylotypes related to Methanobacteriales and Methanosarcinales. Among the Thaumarchaeota, the two most abundant phylotypes were affiliated (97% similarity) with the only cultivated mesophilic thaumarchaeote of marine origin, Nitrosopumilus maritimus. Temporal and spatial comparison of the prokaryotic community structure revealed that three of the most abundant prokaryotic phylotypes, belonging to Actinobacteria, were recovered from all sites both years, suggesting that these Actinobacteria could be important key players in MR ecosystem functioning.


Asunto(s)
Archaea/aislamiento & purificación , Bacterias/aislamiento & purificación , Agua Potable/microbiología , Archaea/clasificación , Archaea/genética , Bacterias/clasificación , Bacterias/genética , Biodiversidad , ADN de Archaea/genética , ADN Bacteriano/genética , ADN Ribosómico/genética , Grecia , Datos de Secuencia Molecular , Filogenia , ARN Ribosómico 16S/genética
18.
Sci Total Environ ; 412-413: 359-65, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22075156

RESUMEN

An integrated approach using biomarkers and contaminant levels in mussels Mytilus galloprovincialis L. was employed to assess chemical contamination in Greek coastal waters within the framework of the MYTIMED program. Biomarkers (metallothioneins, glutathione S-transferase, catalase, acetylcholinesterase and RNA:DNA ratio) have been previously described in mussels caged at 14 sites in coastal areas influenced by different types of anthropogenic activities. This study applied a biomarker index, the Integrated Biomarker Response (IBR) to summarize biomarker responses and relate stress levels to concentrations of organochlorine compounds (PCBs, DDTs), polycyclic aromatic hydrocarbons (PAHs), and metals (Cu, Ni, Fe, Zn) measured in the mussel tissues. The IBR index indicated environmental stress at sites near cities and industries and was overall related to organic contaminants, but also elevated metal concentrations at certain sites. Slightly increased IBR values at few sites away from known pollution sources were not accompanied with increased contaminant levels suggesting stress possibly caused by natural factors. Results confirmed the usefulness of integration of biological effects measurements and chemical analysis for the assessment of chemical contamination in coastal waters.


Asunto(s)
Monitoreo del Ambiente/métodos , Hidrocarburos Clorados/metabolismo , Metales/metabolismo , Mytilus/metabolismo , Hidrocarburos Policíclicos Aromáticos/metabolismo , Contaminantes Químicos del Agua/metabolismo , Animales , Biomarcadores/análisis , Biomarcadores/metabolismo , Cromatografía de Gases y Espectrometría de Masas , Grecia , Hidrocarburos Clorados/análisis , Metales/análisis , Hidrocarburos Policíclicos Aromáticos/análisis , Análisis de Componente Principal , Estadísticas no Paramétricas , Contaminantes Químicos del Agua/análisis
19.
Microb Ecol ; 62(3): 655-68, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21538105

RESUMEN

We investigated the top 30-cm sediment prokaryotic community structure in 5-cm spatial resolution, at an active site of the Amsterdam mud volcano, East Mediterranean Sea, based on the 16S rRNA gene diversity. A total of 339 and 526 sequences were retrieved, corresponding to 25 and 213 unique (≥98% similarity) phylotypes of Archaea and Bacteria, respectively, in all depths. The Shannon-Wiener diversity index H was higher for Bacteria (1.92-4.03) than for Archaea (0.99-1.91) and varied differently between the two groups. Archaea were dominated by anaerobic methanotrophs ANME-1, -2 and -3 groups and were related to phylotypes involved in anaerobic oxidation of methane from similar habitats. The much more complex Bacteria community consisted of 20 phylogenetic groups at the phylum/candidate division level. Proteobacteria, in particular δ-Proteobacteria, was the dominant group. In most sediment layers, the dominant phylotypes of both the Archaea and Bacteria communities were found in neighbouring layers, suggesting some overlap in species richness. The similarity of certain prokaryotic communities was also depicted by using four different similarity indices. The direct comparison of the retrieved phylotypes with those from the Kazan mud volcano of the same field revealed that 40.0% of the Archaea and 16.9% of the Bacteria phylotypes are common between the two systems. The majority of these phylotypes are closely related to phylotypes originating from other mud volcanoes, implying a degree of endemicity in these systems.


Asunto(s)
Archaea/aislamiento & purificación , Bacterias/aislamiento & purificación , Biodiversidad , Sedimentos Geológicos/microbiología , Archaea/genética , Archaea/crecimiento & desarrollo , Bacterias/genética , Bacterias/crecimiento & desarrollo , ADN de Archaea/genética , ADN Bacteriano/genética , Sedimentos Geológicos/química , Mar Mediterráneo , Filogenia , ARN Ribosómico 16S/genética , Agua de Mar/química , Agua de Mar/microbiología , Análisis de Secuencia de ADN , Microbiología del Agua
20.
Front Biosci (Elite Ed) ; 3: 772-87, 2011 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21196350

RESUMEN

Published information on airborne algae and cyanobacteria worldwide and the related human health effects is scarce. Since 1844, a total of 353 morphological taxa (genera or species) have been identified in aerobiological studies. However, due to diverse methodologies and different microorganisms targeted in these studies, direct comparisons on the occurrences of airborne algae and cyanobacteria in various studies are rather dubious. Thirty-eight airborne algae and cyanobacteria were shown to induce allergy, skin irritation, hay fever, rhinitis, sclerosis and respiratory problems when aerosolized and inhaled. Another 14 airborne taxa are known toxin producers posing threat to human health. Most frequently associated with health effects are the genera Chlorella, Scenedesmus, Chlorococcum, Klebsormidium (Hormidium) and Lyngbya. In the air of the Mediterranean city of Thessaloniki, we found 63 algal and cyanobacterial taxa, with 21 reported for the first time in the air. Seven taxa were potentially harmful. Algae and cyanobacteria can contribute significantly in the total air particle load, rendering them as causative agents for health issues when inhaled.


Asunto(s)
Microbiología del Aire , Biodiversidad , Chlorophyta/toxicidad , Cianobacterias/patogenicidad , Monitoreo del Ambiente/estadística & datos numéricos , Exposición por Inhalación/efectos adversos , Ciudades , Grecia , Humanos , Especificidad de la Especie
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