Phaeobacter gallaeciensis
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA19431 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| Other | ||||
| SRR1587449_1.fastq.gz | Fastqsanger.gz | |||
| SRR1587449_2.fastq.gz | Fastqsanger.gz | |||
| SRR1708823.fastq.gz | Fastqsanger.gz | |||
| SRR1708823_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Emiliania huxleyi, an environmentally important marine microalga, has a bloom-and-bust lifestyle in which massive algal blooms appear and fade. Phaeobacter gallaeciensis belongs to the roseobacter clade of α-Proteobacteria, the populations of which wax and wane with that of E. huxleyi. Roseobacter are thought to promote algal growth by biosynthesizing and secreting antibiotics and growth stimulants (auxins). Here we show that P. gallaeciensis switches its secreted small molecule metabolism to the production of potent and selective algaecides, the roseobacticides, in response to p-coumaric acid, an algal lignin breakdown product that is symptomatic of aging algae. This switch converts P. gallaeciensis into an opportunistic pathogen of its algal host.
| S-EPMC3376411 | biostudies-literature
Project description:Phaeobacter gallaeciensis, a member of the abundant marine Roseobacter clade, is known to be an effective colonizer of biotic and abiotic marine surfaces. Production of the antibiotic tropodithietic acid (TDA) makes P. gallaeciensis a strong antagonist of many bacteria, including fish and mollusc pathogens. In addition to TDA, several other secondary metabolites are produced, allowing the mutualistic bacterium to also act as an opportunistic pathogen. Here we provide the manually annotated genome sequences of the P. gallaeciensis strains DSM 17395 and 2.10, isolated at the Atlantic coast of north western Spain and near Sydney, Australia, respectively. Despite their isolation sites from the two different hemispheres, the genome comparison demonstrated a surprisingly high level of synteny (only 3% nucleotide dissimilarity and 88% and 93% shared genes). Minor differences in the genomes result from horizontal gene transfer and phage infection. Comparison of the P. gallaeciensis genomes with those of other roseobacters revealed unique genomic traits, including the production of iron-scavenging siderophores. Experiments supported the predicted capacity of both strains to grow on various algal osmolytes. Transposon mutagenesis was used to expand the current knowledge on the TDA biosynthesis pathway in strain DSM 17395. This first comparative genomic analysis of finished genomes of two closely related strains belonging to one species of the Roseobacter clade revealed features that provide competitive advantages and facilitate surface attachment and interaction with eukaryotic hosts.
| S-EPMC3504968 | biostudies-literature
Project description:The production of N-acyl homoserine lactones (AHLs) is widely distributed within the marine Roseobacter clade, and it was proposed that AHL-mediated quorum sensing (QS) is one of the most common cell-to-cell communication mechanisms in roseobacters. The traits regulated by AHL-mediated QS are yet not known for members of the Roseobacter clade, but production of the antibiotic tropodithietic acid (TDA) was supposed to be controlled by AHL-mediated QS in Phaeobacter spp. We describe here for the first time the functional role of luxR and luxI homologous genes of an organism of the Roseobacter clade, i.e., pgaR and pgaI in Phaeobacter gallaeciensis. Our results demonstrate that the AHL synthase gene pgaI is responsible for production of N-3-hydroxydecanoylhomoserine lactone (3OHC(10)-HSL). Insertion mutants of pgaI and pgaR are both deficient in TDA biosynthesis and the formation of a yellow-brown pigment when grown in liquid marine broth medium. This indicates that in P. gallaeciensis the production of both secondary metabolites is controlled by AHL-mediated QS. Quantitative real-time PCR showed that the transcription level of tdaA, which encodes an essential transcriptional regulator for TDA biosynthesis, decreased 28- and 51-fold in pgaI and pgaR genetic backgrounds, respectively. These results suggest that both the response regulator PgaR and the 3OHC(10)-HSL produced by PgaI induce expression of tdaA, which in turn positively regulates expression of the tda genes. Moreover, we confirmed that TDA can also act as autoinducer in P. gallaeciensis, as previously described for Silicibacter sp. strain TM1040, but only in the presence of the response regulator PgaR.
| S-EPMC3232910 | biostudies-literature
Project description:Phaeobacter gallaeciensis CIP 105210(T) (= DSM 26640(T) = BS107(T)) is the type strain of the species Phaeobacter gallaeciensis. The genus Phaeobacter belongs to the marine Roseobacter group (Rhodobacteraceae, Alphaproteobacteria). Phaeobacter species are effective colonizers of marine surfaces, including frequent associations with eukaryotes. Strain BS107(T) was isolated from a rearing of the scallop Pecten maximus. Here we describe the features of this organism, together with the complete genome sequence, comprising eight circular replicons with a total of 4,448 genes. In addition to a high number of extrachromosomal replicons, the genome contains six genomic island and three putative prophage regions, as well as a hybrid between a plasmid and a circular phage. Phylogenomic analyses confirm previous results, which indicated that the originally reported P. gallaeciensis type-strain deposit DSM 17395 belongs to P. inhibens and that CIP 105210(T) (= DSM 26640(T)) is the sole genome-sequenced representative of P. gallaeciensis.
| S-EPMC4148982 | biostudies-literature
Project description:Phaeobacter gallaeciensis strain ANG1 represents the dominant member of the bacterial consortium within the reproductive accessory nidamental gland (ANG) of the squid Euprymna scolopes. We present a 4.59-Mb assembly of its genome, which may provide clues as to how it benefits its host.
| S-EPMC3133266 | biostudies-literature
Project description:Phaeobacter gallaeciensis can antagonize fish-pathogenic bacteria in vitro, and the purpose of this study was to evaluate the organism as a probiont for marine fish larvae and their feed cultures. An in vivo mechanism of action of the antagonistic probiotic bacterium is suggested using a non-antagonistic mutant. P. gallaeciensis was readily established in axenic cultures of the two microalgae Tetraselmis suecica and Nannochloropsis oculata, and of the rotifer Brachionus plicatilis. P. gallaeciensis reached densities of 10(7) cfu/ml and did not adversely affect growth of algae or rotifers. Vibrio anguillarum was significantly reduced by wild-type P. gallaeciensis, when introduced into these cultures. A P. gallaeciensis mutant that did not produce the antibacterial compound tropodithietic acid (TDA) did not reduce V. anguillarum numbers, suggesting that production of the antibacterial compound is important for the antagonistic properties of P. gallaeciensis. The ability of P. gallaeciensis to protect fish larvae from vibriosis was determined in a bath challenge experiment using a multidish system with 1 larva per well. Unchallenged larvae reached 40% accumulated mortality which increased to 100% when infected with V. anguillarum. P. gallaeciensis reduced the mortality of challenged cod larvae (Gadus morhua) to 10%, significantly below the levels of both the challenged and the unchallenged larvae. The TDA mutant reduced mortality of the cod larvae in some of the replicates, although to a much lesser extent than the wild type. It is concluded that P. gallaeciensis is a promising probiont in marine larviculture and that TDA production likely contributes to its probiotic effect.
| S-EPMC3425499 | biostudies-literature
Project description:Production of the antibiotic tropodithietic acid (TDA) depends on the central phenylacetate catabolic pathway, specifically on the oxygenase PaaABCDE, which catalyzes epoxidation of phenylacetyl-coenzyme A (CoA). Our study was focused on genes of the upper part of this pathway leading to phenylacetyl-CoA as precursor for TDA. Phaeobacter gallaeciensis DSM 17395 encodes two genes with homology to phenylacetyl-CoA ligases (paaK1 and paaK2), which were shown to be essential for phenylacetate catabolism but not for TDA biosynthesis and phenylalanine degradation. Thus, in P. gallaeciensis another enzyme must produce phenylacetyl-CoA from phenylalanine. Using random transposon insertion mutagenesis of a paaK1-paaK2 double mutant we identified a gene (ior1) with similarity to iorA and iorB in archaea, encoding an indolepyruvate:ferredoxin oxidoreductase (IOR). The ior1 mutant was unable to grow on phenylalanine, and production of TDA was significantly reduced compared to the wild-type level (60%). Nuclear magnetic resonance (NMR) spectroscopic investigations using (13)C-labeled phenylalanine isotopomers demonstrated that phenylalanine is transformed into phenylacetyl-CoA by Ior1. Using quantitative real-time PCR, we could show that expression of ior1 depends on the adjacent regulator IorR. Growth on phenylalanine promotes production of TDA, induces expression of ior1 (27-fold) and paaK1 (61-fold), and regulates the production of TDA. Phylogenetic analysis showed that the aerobic type of IOR as found in many roseobacters is common within a number of different phylogenetic groups of aerobic bacteria such as Burkholderia, Cupriavidis, and Rhizobia, where it may also contribute to the degradation of phenylalanine.
| S-EPMC3346364 | biostudies-literature
Project description:Phaeobacter gallaeciensis strain:P11 Genome sequencing
| PRJNA273449 | ENA
Project description:Phaeobacter gallaeciensis strain:P63 Genome sequencing
| PRJNA273593 | ENA
Project description:Phaeobacter gallaeciensis strain:JL2886 Genome sequencing and assembly
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