scholarly journals Picocyanobacterial community structure of freshwater lakes and the Baltic Sea revealed by phylogenetic analyses and clade-specific quantitative PCR

Microbiology ◽  
2008 ◽  
Vol 154 (11) ◽  
pp. 3347-3357 ◽  
Author(s):  
Patricia Sánchez-Baracaldo ◽  
Barbara A. Handley ◽  
Paul K. Hayes
Keyword(s):  
Community Structure ◽  
Baltic Sea ◽  
Quantitative Pcr ◽  
Phylogenetic Analyses ◽  
Freshwater Lakes ◽  
The Baltic Sea ◽  
The Baltic

Acclimation limits of Fucus evanescens along the salinity gradient of the southwestern Baltic Sea

2019 ◽  
Vol 62 (1) ◽  
pp. 31-42
Author(s):  
Katharina Romoth ◽  
Petra Nowak ◽  
Daniela Kempke ◽  
Anna Dietrich ◽  
Christian Porsche ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Salinity Gradient ◽  
Phylogenetic Analyses ◽  
Measurement Data ◽  
Limiting Factor ◽  
Photosynthetic Parameters ◽  
Similar Species ◽  
The Baltic Sea ◽  
Fucus Evanescens ◽  
The Baltic

Abstract Over recent decades, the neophyte Fucus evanescens has extended eastwards along the salinity gradient within the Baltic Sea, indicating gradual adaptation to low salinity conditions. To find out whether F. evanescens can migrate further into the Baltic Sea and potentially become a competitor to the native F. vesiculosus, the acclimation potentials of different F. evanescens and F. vesiculosus populations were investigated with respect to habitat salinity. For both species, pigmentation, water content, and photosynthetic rate were measured under laboratory and field conditions. The instantaneous measurement data and incubation experiment did not show clear differences in the measured photosynthetic parameters between different salinity levels (6–20), or between species. Maximum likelihood phylogenetic analyses of the nuclear marker PDI (a putative protein disulfide isomerase) separated F. vesiculosus and F. evanescens into well-defined groups supporting the hypothesis that the two very similar species do not represent different morphotypes of the same species/gene pool. These findings indicate that – at least for the vegetative stage of F. evanescens – salinity may not be a limiting factor for a further spread into the Baltic Sea.

scholarly journals Benthic cyanobacteria of the genus Nodularia are non-toxic, without gas vacuoles, able to glide and genetically more diverse than planktonic Nodularia

2005 ◽  
Vol 55 (2) ◽  
pp. 555-568 ◽  
Author(s):  
Christina Lyra ◽  
Maria Laamanen ◽  
Jaana M. Lehtimäki ◽  
Anu Surakka ◽  
Kaarina Sivonen
Keyword(s):  
Baltic Sea ◽  
Phylogenetic Analyses ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Benthic Species ◽  
The Baltic Sea ◽  
Ecological Features ◽  
Gas Vacuoles ◽  
Different Types ◽  
The Baltic

Diversity and ecological features of cyanobacteria of the genus Nodularia from benthic, periphytic and soil habitats are less well known than those of Nodularia from planktonic habitats. Novel benthic Nodularia strains were isolated from the Baltic Sea and their morphology, the presence of gas vacuoles, nodularin production, gliding, 16S rRNA gene sequences, rpoB, rbcLX and ndaF genes, and gvpA-IGS regions were examined, as well as short tandemly repeated repetitive sequence fingerprints. Strains were identified as Nodularia spumigena, Nodularia sphaerocarpa or Nodularia harveyana on the basis of the size and shape of the different types of cells and the presence or absence of gas vacuoles. The planktonic strains of N. spumigena mostly had gas vacuoles and produced nodularin, whereas the benthic strains of N. sphaerocarpa and N. harveyana lacked gas vacuoles and did not produce nodularin (except for strain PCC 7804). The benthic strains were also able to glide on surfaces. In the genetic analyses, the planktonic N. spumigena and benthic N. sphaerocarpa formed monophyletic clusters, but the clusters were very closely related. Benthic strains determined as N. harveyana formed the most diverse and distant group of strains. In addition to phylogenetic analyses, the lack of the gvpA-IGS region and ndaF in N. sphaerocarpa and N. harveyana distinguished these species from the planktonic N. spumigena. Therefore, ndaF can be considered as a potential diagnostic tool for detecting and quantifying Baltic Sea bloom-forming, nodularin-producing N. spumigena strains. The data confirm that only one morphologically and genetically distinct planktonic species of Nodularia, N. spumigena, and at least two benthic species, N. sphaerocarpa and N. harveyana, exist in the Baltic Sea.

scholarly journals Harmonizing large data sets reveals novel patterns in the Baltic Sea phytoplankton community structure

2013 ◽  
Vol 473 ◽  
pp. 53-66 ◽  
Author(s):  
K Olli ◽  
O Trikk ◽  
R Klais ◽  
R Ptacnik ◽  
T Andersen ◽  
...  
Keyword(s):  
Community Structure ◽  
Baltic Sea ◽  
Phytoplankton Community ◽  
Large Data ◽  
Large Data Sets ◽  
Data Sets ◽  
Phytoplankton Community Structure ◽  
The Baltic Sea ◽  
The Baltic

scholarly journals Heatwave-associated Vibrio infections in Germany, 2018 and 2019

2021 ◽  
Vol 26 (41) ◽  
Author(s):  
Thomas Theo Brehm ◽  
Laura Berneking ◽  
Meike Sena Martins ◽  
Susann Dupke ◽  
Daniela Jacob ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Phylogenetic Analyses ◽  
Wound Infections ◽  
The Baltic Sea ◽  
Microbiological Characteristics ◽  
Moderate Salinity ◽  
Ear Infections ◽  
Clonal Lines ◽  
The Baltic ◽  
Microbiological Data

Background Vibrio spp. are aquatic bacteria that prefer warm seawater with moderate salinity. In humans, they can cause gastroenteritis, wound infections, and ear infections. During the summers of 2018 and 2019, unprecedented high sea surface temperatures were recorded in the German Baltic Sea. Aim We aimed to describe the clinical course and microbiological characteristics of Vibrio infections in Germany in 2018 and 2019. Methods We performed an observational retrospective multi-centre cohort study of patients diagnosed with domestically-acquired Vibrio infections in Germany in 2018 and 2019. Demographic, clinical, and microbiological data were assessed, and isolates were subjected to whole genome sequencing and antimicrobial susceptibility testing. Results Of the 63 patients with Vibrio infections, most contracted the virus between June and September, primarily in the Baltic Sea: 44 (70%) were male and the median age was 65 years (range: 2–93 years). Thirty-eight patients presented with wound infections, 16 with ear infections, six with gastroenteritis, two with pneumonia (after seawater aspiration) and one with primary septicaemia. The majority of infections were attributed to V. cholerae (non–O1/non-O139) (n = 30; 48%) or V. vulnificus (n = 22; 38%). Phylogenetic analyses of 12 available isolates showed clusters of three identical strains of V. vulnificus, which caused wound infections, suggesting that some clonal lines can spread across the Baltic Sea. Conclusions During the summers of 2018 and 2019, severe heatwaves facilitated increased numbers of Vibrio infections in Germany. Since climate change is likely to favour the proliferation of these bacteria, a further increase in Vibrio-associated diseases is expected.

scholarly journals Genomes of Novel Microbial Lineages Assembled from the Sub-Ice Waters of Lake Baikal

2017 ◽  
Vol 84 (1) ◽  
Author(s):  
Pedro J. Cabello-Yeves ◽  
Tamara I. Zemskaya ◽  
Riccardo Rosselli ◽  
Felipe H. Coutinho ◽  
Alexandra S. Zakharenko ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Snow Cover ◽  
Water Column ◽  
Lake Baikal ◽  
Light Penetration ◽  
Freshwater Lakes ◽  
The Baltic Sea ◽  
Content Type ◽  
Freshwater Bodies ◽  
The Baltic

ABSTRACT We present a metagenomic study of Lake Baikal (East Siberia). Two samples obtained from the water column under the ice cover (5 and 20 m deep) in March 2016 have been deep sequenced and the reads assembled to generate metagenome-assembled genomes (MAGs) that are representative of the microbes living in this special environment. Compared with freshwater bodies studied around the world, Lake Baikal had an unusually high fraction of Verrucomicrobia. Other groups, such as Actinobacteria and Proteobacteria, were in proportions similar to those found in other lakes. The genomes (and probably cells) tended to be small, presumably reflecting the extremely oligotrophic and cold prevalent conditions. Baikal microbes are novel lineages recruiting very little from other water bodies and are distantly related to other freshwater microbes. Despite their novelty, they showed the closest relationship to genomes discovered by similar approaches from other freshwater lakes and reservoirs. Some of them were particularly similar to MAGs from the Baltic Sea, which, although it is brackish, connected to the ocean, and much more eutrophic, has similar climatological conditions. Many of the microbes contained rhodopsin genes, indicating that, in spite of the decreased light penetration allowed by the thick ice/snow cover, photoheterotrophy could be widespread in the water column, either because enough light penetrates or because the microbes are already adapted to the summer ice-less conditions. We have found a freshwater SAR11 subtype I/II representative showing striking synteny with Pelagibacter ubique strains, as well as a phage infecting the widespread freshwater bacterium Polynucleobacter. IMPORTANCE Despite the increasing number of metagenomic studies on different freshwater bodies, there is still a missing component in oligotrophic cold lakes suffering from long seasonal frozen cycles. Here, we describe microbial genomes from metagenomic assemblies that appear in the upper water column of Lake Baikal, the largest and deepest freshwater body on Earth. This lake is frozen from January to May, which generates conditions that include an inverted temperature gradient (colder up), decrease in light penetration due to ice, and, especially, snow cover, and oligotrophic conditions more similar to the open-ocean and high-altitude lakes than to other freshwater or brackish systems. As could be expected, most reconstructed genomes are novel lineages distantly related to others in cold environments, like the Baltic Sea and other freshwater lakes. Among them, there was a broad set of streamlined microbes with small genomes/intergenic spacers, including a new nonmarine Pelagibacter-like (subtype I/II) genome.

scholarly journals Bacterioplankton dynamics driven by inter-annual variation in phytoplankton spring bloom communities in the Baltic Sea

2019 ◽  
Author(s):  
María Teresa Camarena-Gómez ◽  
Clara Ruiz-González ◽  
Jonna Piiparinen ◽  
Tobias Lipsewers ◽  
Cristina Sobrino ◽  
...  
Keyword(s):  
Community Structure ◽  
Bacterial Community ◽  
Baltic Sea ◽  
Carbon Cycling ◽  
Bacterial Production ◽  
Bacterial Community Structure ◽  
Spring Bloom ◽  
The Baltic Sea ◽  
The Baltic ◽  
And Function

AbstractIn the Baltic Sea, climate change has caused shifts in the phytoplankton spring bloom communities with co-occurrence of diatoms and dinoflagellates. Such changes likely affect the composition and function of associated bacterioplankton, key members of the carbon cycling, although the actual effects are unknown. To understand how changes in phytoplankton impact on bacterioplankton composition and function, we analysed bacterioplankton communities and their production during different phases of the spring bloom in four consecutive years across the Baltic Sea, and related them to environmental variables. Phytoplankton communities varied largely in composition, modifying the taxonomic structure and richness of the associated bacterioplankton assemblages. In presence of certain diatoms (Achnanthes taeniata, Skeletonema costatum and Chaetoceros spp.), bacterial production and diversity were high and with more relative abundance of Flavobacteriia, Gammaproteobacteria and Betaproteobacteria. This bacterial community structure correlated positively with high diatom biomass and with high bacterial production rates. In contrast, during dinoflagellate-dominated blooms or when the diatom Thalassiosira baltica was abundant, both bacterial production rates and diversity were low, with bacterial communities dominated by SAR11 and Rhodobacteraceae. Our results demonstrate that, changes in the phytoplankton spring bloom will have profound consequences on bacterial community structure and their role in carbon cycling.

Sign in / Sign up

Export Citation Format

Share Document