Topic
Alteromonas
About: Alteromonas is a research topic. Over the lifetime, 400 publications have been published within this topic receiving 14766 citations.
Papers published on a yearly basis
Papers
TL;DR: The culturability of abundant members of the domain bacteria in North Sea bacterioplankton was investigated by a combination of various cultivation strategies and cultivation-independent 16S rRNA-based techniques and predicted a limit to the isolation of unculturable marine bacteria, particularly the gamma-proteobacterial SAR86 cluster.
Abstract: The culturability of abundant members of the domain Bacteria in North Sea bacterioplankton was investigated by a combination of various cultivation strategies and cultivation-independent 16S rRNA-based techniques. We retrieved 16S rRNA gene (rDNA) clones from environmental DNAs and determined the in situ abundance of different groups and genera by fluorescence in situ hybridization (FISH). A culture collection of 145 strains was established by plating on oligotrophic medium. Isolates were screened by FISH, amplified ribosomal DNA restriction analysis (ARDRA), and sequencing of representative 16S rDNAs. The majority of isolates were members of the genera Pseudoalteromonas, Alteromonas, and Vibrio. Despite being readily culturable, they constituted only a minor fraction of the bacterioplankton community. They were not detected in the 16S rDNA library, and FISH indicated rare (<1% of total cell counts) occurrence as large, rRNA-rich, particle-associated bacteria. Conversely, abundant members of the Cytophaga-Flavobacteria and gamma proteobacterial SAR86 clusters, identified by FISH as 17 to 30% and up to 10% of total cells in the North Sea bacterioplankton, respectively, were cultured rarely or not at all. Whereas SAR86-affiliated clones dominated the 16S rDNA library (44 of 53 clones), no clone affiliated to the Cytophaga-Flavobacterum cluster was retrieved. The only readily culturable abundant group of marine bacteria was related to the genus Roseobacter. The group made up 10% of the total cells in the summer, and the corresponding sequences were also present in our clone library. Rarefaction analysis of the ARDRA patterns of all of the isolates suggested that the total culturable diversity by our method was high and still not covered by the numbers of isolated strains but was almost saturated for the gamma proteobacteria. This predicts a limit to the isolation of unculturable marine bacteria, particularly the gamma-proteobacterial SAR86 cluster, as long as no new techniques for isolation are available and thus contrasts with more optimistic accounts of the culturability of marine bacterioplankton.
676 citations
TL;DR: It is proposed that ice diatom assemblages provide niches conducive to the proliferation of a diverse array of psychrophilic bacterial species.
Abstract: The bacterial populations associated with sea ice sampled from Antarctic coastal areas were investigated by use of a phenotypic approach and a phylogenetic approach based on genes encoding 16S rRNA (16S rDNA). The diversity of bacteria associated with sea ice was also compared with the bacterial diversity of seawater underlying sea ice. Psychrophilic (optimal growth temperature, 20 degrees C; growth can occur at approximately 4 degrees C) isolated from sea ice cores and under-ice seawater were quite similar. Overall, bacterial isolates from Antarctic sea ice were found to belong to four phylogenetic groups, the alpha and gamma subdivisions of the Proteobacteria, the gram-positive branch, and the Flexibacter-Bacteroides-Cytophaga phylum. Most of the sea ice strains examined appeared to be novel taxa based on phylogenetic comparisons, with 45% of the strains being psychrophilic. 16S rDNA sequence analysis revealed that psychrophilic strains belonged to the genera Colwellia, Shewanella, Marinobacter, Planococcus, and novel phylogenetic lineages adjacent to Colwellia and Alteromonas and within the Flexibacter-Bacteroides-Cytophaga phylum. Psychrotrophic strains were found to be members of the genera Pseudoalteromonas, Psychrobacter, Halomonas, Pseudomonas, Hyphomonas, Sphingomonas, Arthrobacter, Planococcus, and Halobacillus. From this survey, it is proposed that ice diatom assemblages provide niches conducive to the proliferation of a diverse array of psychrophilic bacterial species.
547 citations
TL;DR: Small-subunit ribosomal DNA sequences were determined for 17 strains belonging to the genera Alteromonas, Shewanella, Vibrio, and Pseudomonas and these sequences were analyzed by phylogenetic methods, and it was suggested that the genus Alteromon as should be split into two genera.
Abstract: Small-subunit ribosomal DNA sequences were determined for 17 strains belonging to the genera Alteromonas, Shewanella, Vibrio, and Pseudomonas, and these sequences were analyzed by phylogenetic methods. The resulting data confirmed the existence of the genera Shewanella and Moritella, but suggested that the genus Alteromonas should be split into two genera. We propose that a new genus, the genus Pseudoalteromonas, should be created to accommodate 11 species that were previously Alteromonas species, including Pseudoalteromonas atlantica comb. nov., Pseudoalteromonas aurantia comb. nov., Pseudoalteromonas carrageenovora comb. nov., Pseudoalteromonas citrea comb. nov., Pseudoalteromonas denitrificans comb. nov., Pseudoalteromonas espejiana comb. nov., Pseudoalteromonas haloplanktis comb. nov. (with two subspecies, Pseudoalteromonas haloplanktis subsp. haloplanktis comb. nov. and Pseudoalteromonas haloplanktis subsp. tetraodonis comb. nov.), Pseudoalteromonas luteoviolacea comb. nov., Pseudoalteromonas nigrifaciens comb. nov., Pseudoalteromonas rubra comb. nov., and Pseudoalteromonas undina comb. nov., and one species that previously was placed in the genus Pseudomonas, Pseudoalteromonas piscicida comb. nov. We propose that P. haloplanktis (type strain, ATCC 14393) should be the type species of the genus Pseudoalteromonas. At this time the emended genus Alteromonas is restricted to a single species, Alteromonas macleodii.
441 citations
TL;DR: The life strategy of rapidly enriched culturable γ-proteobacteria could thus be described as a “feast and famine” existence involving different activation levels of substrate concentration.
Abstract: Enrichment experiments with North Sea bacterioplankton were performed to test if rapid incubationinduced changes in community structure explain the frequent isolation of members of a few particular bacterial lineages or if readily culturable bacteria are common in the plankton but in a state of dormancy. A metabolic inhibitor of cell division (nalidixic acid [NA]) was added to substrate-amended (S1) and unamended (S2) grazer-free seawater samples, and shifts in community composition and per cell DNA and protein content were compared with untreated controls. In addition, starvation survival experiments were performed on selected isolates. Incubations resulted in rapid community shifts towards typical culturable genera rather than in the activation of either dormant cells or the original DNA-rich bacterial fraction. Vibrio spp. and members of the Alteromonas/Colwellia cluster (A/C) were selectively enriched in S1 and S2, respectively, and this trend was even magnified by the addition of NA. These increases corresponded with the rise of cell populations with distinctively different but generally higher protein and DNA content in the various treatments. Uncultured dominant g-proteobacteria affiliating with the SAR86 cluster and members of the culturable genus Oceanospirillum were not enriched or activated, but there was no indication of substrate-induced cell death, either. Strains of Vibrio and A/C maintained high ribosome levels in pure cultures during extended periods of starvation, whereas Oceanospirillum spp. did not. The life strategy of rapidly enriched culturable g-proteobacteria could thus be described as a “feast and famine” existence involving different activation levels of substrate concentration.
282 citations
TL;DR: It is proposed that an increased resilience of the molecular surface and a less rigid protein core, with less interdomain interactions, are determining factors of the conformational flexibility that allows efficient enzyme catalysis in cold environments.
221 citations
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Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 14 |
| 2024 | 20 |
| 2023 | 33 |
| 2022 | 39 |
| 2021 | 17 |
| 2020 | 14 |