Exemplar Abstract for Shewanella baltica Ziemke et al. 1998.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  

2019 ◽  
Vol 67 (43) ◽  
pp. 12013-12025 ◽  
Author(s):  
Junli Zhu ◽  
Yuwei Zhang ◽  
Jingmin Deng ◽  
Hanyun Jiang ◽  
Liumin Zhuang ◽  
...  

mSystems ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Jie Deng ◽  
Jennifer M. Auchtung ◽  
Konstantinos T. Konstantinidis ◽  
Ingrid Brettar ◽  
Manfred G. Höfle ◽  
...  

ABSTRACT Shewanella baltica was the dominant culturable nitrate-reducing bacterium in the eutrophic and strongly stratified Baltic Sea in the 1980s, where it primarily inhabited the oxic-anoxic transition zone. The genomic structures of 46 of these isolates were investigated through comparative genomic hybridization (CGH), which revealed a gradient of genomic similarity, ranging from 65% to as high as 99%. The core genome of the S. baltica species was enriched in anaerobic respiration-associated genes. Auxiliary genes, most of which locate within a few genomic islands (GIs), were nonuniformly distributed among the isolates. Specifically, hypothetical and mobile genetic element (MGE)-associated genes dominated intraclade gene content differences, whereas gain/loss of functional genes drove gene content differences among less related strains. Among the major S. baltica clades, gene signatures related to specific redox-driven and spatial niches within the water column were identified. For instance, genes involved in anaerobic respiration of sulfur compounds may provide key adaptive advantages for clade A strains in anoxic waters where sulfur-containing electron acceptors are present. Genes involved in cell motility, in particular, a secondary flagellar biosynthesis system, may be associated with the free-living lifestyle by clade E strains. Collectively, this study revealed characteristics of genome variations present in the water column and active speciation of S. baltica strains, driven by niche partitioning and horizontal gene transfer (HGT). IMPORTANCE Speciation in nature is a fundamental process driving the formation of the vast microbial diversity on Earth. In the central Baltic Sea, the long-term stratification of water led to formation of a large-scale vertical redoxcline that provided a gradient of environmental niches with respect to the availability of electron acceptors and donors. The region was home to Shewanella baltica populations, which composed the dominant culturable nitrate-reducing bacteria, particularly in the oxic-anoxic transition zone. Using the collection of S. baltica isolates as a model system, genomic variations showed contrasting gene-sharing patterns within versus among S. baltica clades and revealed genomic signatures of S. baltica clades related to redox niche specialization as well as particle association. This study provides important insights into genomic mechanisms underlying bacterial speciation within this unique natural redoxcline.


2017 ◽  
Vol 61 (4) ◽  
pp. 445-449 ◽  
Author(s):  
Natalia Walczak ◽  
Krzysztof Puk ◽  
Leszek Guz

AbstractIntroduction:Ornamental fish can suffer from different bacterial diseases. Among them the most prevalent are infections caused byAeromonas, Shewanella, Citrobacter, Plesiomonas, Edwardsiella, andPseudomonas.But there is a broad spectrum of rarely identified bacteria which may be causative agents of diseases. The aim of the study was to determine the species of bacteria pathogenic for fish which are prevalent in aquariums.Material and Methods:Bacteria were isolated from infected ornamental fish from pet shops and private aquariums in the Lublin region in 2015 and classified to species using MALDI-TOF MS.Results:A total of 182 isolates from ornamental fish were identified. The most frequent bacteria found in diseased fish wereAeromonas veronii(30.8% of total number of strains),A. hydrophila(18.7%),Shewanella putrefaciens(7.1%),Citrobacter freundii(7.1%),Pseudomonas spp. (7.1%),Shewanella baltica(4.9%), andPlesiomonas shigelloides(3.3%).Conclusion:Isolated bacterial species are facultative pathogens for fish and humans and may be isolated from fish without apparent symptoms of the disease.


2020 ◽  
Vol 21 (12) ◽  
pp. 4338 ◽  
Author(s):  
Anna Kloska ◽  
Grzegorz M. Cech ◽  
Marta Sadowska ◽  
Klaudyna Krause ◽  
Agnieszka Szalewska-Pałasz ◽  
...  

Marine bacteria display significant versatility in adaptation to variations in the environment and stress conditions, including temperature shifts. Shewanella baltica plays a major role in denitrification and bioremediation in the marine environment, but is also identified to be responsible for spoilage of ice-stored seafood. We aimed to characterize transcriptional response of S. baltica to cold stress in order to achieve a better insight into mechanisms governing its adaptation. We exposed bacterial cells to 8 °C for 90 and 180 min, and assessed changes in the bacterial transcriptome with RNA sequencing validated with the RT-qPCR method. We found that S. baltica general response to cold stress is associated with massive downregulation of gene expression, which covered about 70% of differentially expressed genes. Enrichment analysis revealed upregulation of only few pathways, including aminoacyl-tRNA biosynthesis, sulfur metabolism and the flagellar assembly process. Downregulation was observed for fatty acid degradation, amino acid metabolism and a bacterial secretion system. We found that the entire type II secretion system was transcriptionally shut down at low temperatures. We also observed transcriptional reprogramming through the induction of RpoE and repression of RpoD sigma factors to mediate the cold stress response. Our study revealed how diverse and complex the cold stress response in S. baltica is.


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