Psychrobacter glaciei sp. nov., isolated from the ice core of an Arctic glacier

Zeng, Yangsu; Yu, Yong; Liu, Yang; Li, Huirong

doi:10.1099/ijsem.0.000939

Cited by 24 publications

(17 citation statements)

References 30 publications

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“…In our study, by far the most frequent genus was Psychrobacter accounting for 70 out of 195 (35.9%) isolates based on 16S rRNA information but unfortunately this does not allow species-specific distinction. For future work on specific candidates of this genus molecular characterization will target the gyrB gene [ 59 ].…”

Section: Discussionmentioning

confidence: 99%

Isolation and characterization of native probiotics for fish farming

et al. 2018

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BackgroundInnovations in fish nutrition act as drivers for the sustainable development of the rapidly expanding aquaculture sector. Probiotic dietary supplements are able to improve health and nutrition of livestock, but respective bacteria have mainly been isolated from terrestrial, warm-blooded hosts, limiting an efficient application in fish. Native probiotics adapted to the gastrointestinal tract of the respective fish species will establish within the original host more efficiently.ResultsHere, 248 autochthonous isolates were cultured from the digestive system of three temperate flatfish species. Upon 16S rRNA gene sequencing of 195 isolates, 89.7% (n = 175) Gram-negatives belonging to the Alpha- (1.0%), Beta- (4.1%) and Gammaproteobacteria (84.6%) were identified. Candidate probiotics were further characterized using in vitro assays addressing 1) inhibition of pathogens, 2) degradation of plant derived anti-nutrient (saponin) and 3) the content of essential fatty acids (FA) and their precursors. Twelve isolates revealed an inhibition towards the common fish pathogen Tenacibaculum maritimum, seven were able to metabolize saponin as sole carbon and energy source and two isolates 012 Psychrobacter sp. and 047 Paracoccus sp. revealed remarkably high contents of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Furthermore, a rapid and cost-effective method to coat feed pellets revealed high viability of the supplemented probiotics over 54 d of storage at 4°C.ConclusionsHere, a strategy for the isolation and characterization of native probiotic candidates is presented that can easily be adapted to other farmed fish species. The simple coating procedure assures viability of probiotics and can thus be applied for the evaluation of probiotic candidates in the future.

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Section: Discussionmentioning

confidence: 99%

Isolation and characterization of native probiotics for fish farming

et al. 2018

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“…Here, we investigated the evolutionary history of the genus Psychrobacter, a group of closely related bacteria with a broad environmental distribution. Species of Psychrobacter have been recovered through culture-based and sequenced-based methods from a range of animal microbiomes, including marine mammal skin [19], respiratory blow [20], and guts [21][22][23]; the gastrointestinal tracts of birds [24,25] and fish [26]; and many nonhost environments such as sea water [27], sea ice [28], marine sediment [29], glacial ice [30], and permafrost soil [31]. Some Psychrobacter species are capable of causing disease in mammalian hosts [32,33].…”

Section: Introductionmentioning

confidence: 99%

Free-living psychrophilic bacteria of the genusPsychrobacterare descendants of pathobionts

Welter

Ruaud

Henseler

et al. 2020

Preprint

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Host-adapted microbiota are generally thought to have evolved from free-living ancestors. This process is in principle reversible, but examples are few. The genus Psychrobacter (family Moraxellaceae, phylum Gamma-Proteobacteria) includes species inhabiting diverse and mostly polar environments, such as sea ice and marine animals. To probe the evolutionary history of Psychrobacter, we analyzed 85 Psychrobacter strains by comparative genomics and phenotyping under 24 different growth conditions. Genome-based phylogeny shows Psychrobacter are derived from Moraxella, which are warm-adapted pathobionts. Psychrobacter strains form two ecotypes based on growth temperature: flexible (FE, growth at 4 - 37C), and restricted (RE, 4 - 25C). FE strains, which can be either phylogenetically basal or derived, have smaller genomes and higher transposon copy numbers. RE strains have larger genomes, and show genomic adaptations towards a psychrophilic lifestyle and are phylogenetically derived only. We then assessed Psychrobacter abundance in 86 mostly wild polar bear stools and tested persistence of select strains in germfree mice. Psychrobacter (both FE and RE) was enriched in stool of polar bears feeding on mammals, but only FE strains persisted in germfree mice. Together these results indicate growth at 37°C is ancestral in Psychrobacter, lost in many derived species, and likely necessary to colonize the mammalian gut.

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“…Marinomonas mediterranea MMB-1 was chosen as outgroup. Bar represents 0.008 substitution per nucleotide position sequence similarity value less than 98.6% in 16S rRNA with the closest type strain has been suggested to indicate a new species (Kim et al 2014;Chun et al 2018) and in fact, for this particular genus, values higher than this threshold have also been reported for novel Psychrobacter species (Zeng et al 2016). Moreover, EPS-5 does show physical differences from the features of P. ciconiae described by Kämpfer et al (2015), especially concerning its coccus shape and sugar utilisation.…”

Section: Discussionmentioning

confidence: 97%

Phylogenetics and antibacterial properties of exopolysaccharides from marine bacteria isolated from Mauritius seawater

et al. 2019

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Purpose The marine environment harbours diverse bacterial species which can be exploited for the production of valuable compounds such as exopolysaccharides (EPS) which hold promises for biotechnological applications. The coastal waters of Mauritius is a relatively underexplored marine environment and in this study, isolated bacterial species were tested for the production of EPS exhibiting antibacterial properties against human bacterial pathogens from the genera Acinetobacter, Bacillus, Campylobacter, Enterobacter, Enterococcus, Escherichia, Proteus, Pseudomonas, Salmonella, Streptococcus and Staphylococcus. Methods Bacteria were first isolated from seawater samples. Using the disc diffusion method, their EPS were tested for antibacterial effects through two screenings, with each involving a different set of arbitrarily chosen group of pathogens. The microorganisms producing antibacterial EPS were subsequently identified by morphological, biochemical and 16S rRNAbased phylogenetic analyses. Those EPS exhibiting broadest antibacterial activities were eventually characterised by Fouriertransform infrared spectroscopy (FTIR) and thin-layer chromatography (TLC). Results Eight EPS were found to display antibacterial effects against more than half of the pathogens and the microorganisms producing them were identified as Bacillus, Halomonas, Psychrobacter and Alcaligenes species. However, only two of these EPS were found to be the most active, with their MIC values ranging between 62.5 and 500 μg/ml. FTIR and TLC analyses revealed the presence of carboxyl, hydroxyl and amide as well as sulphate for the EPS, with glucose or fructose being the main sugar. Conclusion The results suggest that Mauritius seawater can be a source of biotechnologically useful microorganisms, producing EPS having potential as antimicrobial agents. DNA sequence data also suggest possible novel bacterial species.

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Psychrobacter glaciei sp. nov., isolated from the ice core of an Arctic glacier

Cited by 24 publications

References 30 publications

Isolation and characterization of native probiotics for fish farming

Isolation and characterization of native probiotics for fish farming

Free-living psychrophilic bacteria of the genusPsychrobacterare descendants of pathobionts

Phylogenetics and antibacterial properties of exopolysaccharides from marine bacteria isolated from Mauritius seawater

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