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.

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 Genomic and Seasonal Variations among Aquatic Phages Infecting the Baltic Sea Gammaproteobacterium Rheinheimera sp. Strain BAL341

2019 ◽  
Vol 85 (18) ◽  
Author(s):  
E. Nilsson ◽  
K. Li ◽  
J. Fridlund ◽  
S. Šulčius ◽  
C. Bunse ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Seasonal Variations ◽  
Aquatic Ecosystems ◽  
Model Systems ◽  
Rrna Gene ◽  
The Baltic Sea ◽  
Host System ◽  
Host Interactions ◽  
Metabolic Genes ◽  
The Baltic

ABSTRACT Knowledge in aquatic virology has been greatly improved by culture-independent methods, yet there is still a critical need for isolating novel phages to identify the large proportion of “unknowns” that dominate metagenomes and for detailed analyses of phage-host interactions. Here, 54 phages infecting Rheinheimera sp. strain BAL341 (Gammaproteobacteria) were isolated from Baltic Sea seawater and characterized through genome content analysis and comparative genomics. The phages showed a myovirus-like morphology and belonged to a novel genus, for which we propose the name Barbavirus. All phages had similar genome sizes and numbers of genes (80 to 84 kb; 134 to 145 genes), and based on average nucleotide identity and genome BLAST distance phylogeny, the phages were divided into five species. The phages possessed several genes involved in metabolic processes and host signaling, such as genes encoding ribonucleotide reductase and thymidylate synthase, phoH, and mazG. One species had additional metabolic genes involved in pyridine nucleotide salvage, possibly providing a fitness advantage by further increasing the phages’ replication efficiency. Recruitment of viral metagenomic reads (25 Baltic Sea viral metagenomes from 2012 to 2015) to the phage genomes showed pronounced seasonal variations, with increased relative abundances of barba phages in August and September synchronized with peaks in host abundances, as shown by 16S rRNA gene amplicon sequencing. Overall, this study provides detailed information regarding genetic diversity, phage-host interactions, and temporal dynamics of an ecologically important aquatic phage-host system. IMPORTANCE Phages are important in aquatic ecosystems as they influence their microbial hosts through lysis, gene transfer, transcriptional regulation, and expression of phage metabolic genes. Still, there is limited knowledge of how phages interact with their hosts, especially at fine scales. Here, a Rheinheimera phage-host system constituting highly similar phages infecting one host strain is presented. This relatively limited diversity has previously been seen only when smaller numbers of phages have been isolated and points toward ecological constraints affecting the Rheinheimera phage diversity. The variation of metabolic genes among the species points toward various fitness advantages, opening up possibilities for future hypothesis testing. Phage-host dynamics monitored over several years point toward recurring “kill-the-winner” oscillations and an ecological niche fulfilled by this system in the Baltic Sea. Identifying and quantifying ecological dynamics of such phage-host model systems in situ allow us to understand and study the influence of phages on aquatic ecosystems.

Evaluation of the distribution of fecal indicator bacteria in a river system depending on different types of land use in the southern watershed of the Baltic Sea

2015 ◽  
Vol 23 (5) ◽  
pp. 4073-4085 ◽  
Author(s):  
Anna Gotkowska-Płachta ◽  
Iwona Gołaś ◽  
Ewa Korzeniewska ◽  
Józef Koc ◽  
Andrzej Rochwerger ◽  
...  
Keyword(s):  
Land Use ◽  
Baltic Sea ◽  
Fecal Indicator Bacteria ◽  
River System ◽  
Indicator Bacteria ◽  
The Baltic Sea ◽  
Fecal Indicator ◽  
Different Types ◽  
The Baltic

scholarly journals Diversity of Pico- to Mesoplankton Along the 2000 km Salinity Gradient of the Baltic Sea

2015 ◽  
Author(s):  
Yue OO Hu ◽  
Bengt Karlson ◽  
Sophie Charvet ◽  
Anders F Andersson
Keyword(s):  
Baltic Sea ◽  
Deep Sequencing ◽  
High Throughput Sequencing ◽  
Salinity Gradient ◽  
Niche Partitioning ◽  
Freshwater Ecosystems ◽  
Marker Genes ◽  
Rrna Gene ◽  
The Baltic Sea ◽  
The Baltic

Microscopic plankton form the productive base of both marine and freshwater ecosystems and are key drivers of global biogeochemical cycles of carbon and nutrients. Plankton diversity is immense with representations from all major phyla within the three domains of life. So far, plankton monitoring has mainly been based on microscopic identification, which has limited sensitivity and reproducibility, not least because of the numerical majority of plankton being unidentifiable under the light microscope. High-throughput sequencing of taxonomic marker genes offers a means to identify taxa inaccessible by traditional methods; thus, recent studies have unveiled an extensive previously unknown diversity of plankton. Here, we conducted ultra-deep Illumina sequencing (average 105 sequences/sample) of rRNA gene amplicons of surface water eukaryotic and bacterial plankton communities along a 2000 km transect following the salinity gradient of the Baltic Sea. Community composition was strongly correlated with salinity for both bacterial and eukaryotic plankton assemblages, highlighting the importance of salinity for structuring the biodiversity within this ecosystem. The distribution of major planktonic taxa followed expected patterns as observed in monitoring programs, but also novel groups to the Baltic were identified, such as relatives to the coccolithophore Emiliana huxleyi in the northern Baltic Sea. The deep sequencing also enabled accurate enumeration of highly resolved (> 99% identity) operational taxonomic units, which revealed contrasting distribution profiles among closely related populations, reflecting niche partitioning into ecotypes. This study provides the first ultra-deep sequencing-based survey on eukaryotic and bacterial plankton biogeography in the Baltic Sea.

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 THE BALTIC SEA - A SEMI-ENCLOSED SEA, AS SEEN BY THE HYDROLOGIST

1975 ◽  
Vol 6 (2) ◽  
pp. 115-136 ◽  
Author(s):  
MALIN FALKENMARK ◽  
ZDZISLAW MIKULSKI
Keyword(s):  
Water Balance ◽  
Baltic Sea ◽  
International Cooperation ◽  
The Baltic Sea ◽  
Water Renewal ◽  
Ecological Features ◽  
The Baltic ◽  
General Configuration ◽  
Long Term Variations

The paper discusses water renewal of the Baltic Sea, a semi-enclosed basin, the general configuration of the water balance, the size and distribution of its individual elements and the interrelations between them. Connections between long-term variations in the water balance and certain ecological features are stressed. To make possible a deepened understanding of the water renewal, international cooperation has been organized between the seven riparian countries.

Comparison of wintertime eukaryotic community from sea ice and open water in the Baltic Sea, based on sequencing of the 18S rRNA gene

Polar Biology ◽  
2011 ◽  
Vol 35 (6) ◽  
pp. 875-889 ◽  
Author(s):  
Markus Majaneva ◽  
Janne-Markus Rintala ◽  
Maria Piisilä ◽  
David P. Fewer ◽  
Jaanika Blomster
Keyword(s):  
Sea Ice ◽  
Baltic Sea ◽  
18S Rrna ◽  
Open Water ◽  
18S Rrna Gene ◽  
Rrna Gene ◽  
The Baltic Sea ◽  
Eukaryotic Community ◽  
The Baltic

scholarly journals Belliella baltica gen. nov., sp. nov., a novel marine bacterium of the Cytophaga–Flavobacterium–Bacteroides group isolated from surface water of the central Baltic Sea

2004 ◽  
Vol 54 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Ingrid Brettar ◽  
Richard Christen ◽  
Manfred G. Höfle
Keyword(s):  
Fatty Acid ◽  
16S Rrna ◽  
16S Rrna Gene ◽  
Baltic Sea ◽  
Rrna Gene ◽  
Fatty Acid Profiles ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
The Family ◽  
The Baltic

Two bacterial isolates from the Baltic Sea, BA1 and BA134T, were characterized for their physiological and biochemical features, fatty acid profiles and phylogenetic position based on 16S rRNA gene sequences. The strains were isolated from surface water of the central Baltic Sea during the decay of a plankton bloom. Phylogenetic analysis of their 16S rRNA gene sequences revealed a clear affiliation to the family ‘Flexibacteriaceae’ and showed highest sequence similarity (91 %) to Cyclobacterium marinum. The G+C content of the DNA was 35·4 mol%. The strains were pink-coloured due to carotinoids, Gram-negative, rod-shaped and catalase- and oxidase-positive. Growth was observed at 0–6 % salinity, with good growth at 0–3 %. Temperature for growth was 4–37 °C, with an optimum around 25 °C. The fatty acid profiles were dominated by branched-chain fatty acids (70 %), with a high abundance of iso-C15 : 0 (29–33 %), iso-C17 : 1 ω9c (7–10 %) and C17 : 1 ω6c (5–10 %). According to their morphology, physiology, fatty acid composition, 16S rRNA gene sequences and DNA–DNA similarity, on one hand, the described bacteria are considered to be members of the same novel species; on the other hand, they are suggested as a novel genus of the family ‘Flexibacteriaceae’. To honour the late aquatic microbiologist Russell T. Bell, the name Belliella baltica gen. nov, sp. nov. is suggested for the Baltic Sea isolates, for which the type strain is BA134T (=DSM 15883T=LMG 21964T=CIP 108006T).

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