scholarly journals First record of the endophytic bacteria of Deschampsia antarctica Ė. Desv. from two distant localities of the maritime Antarctic

2021 ◽  
Vol 11 (1) ◽  
pp. 134-153
Author(s):  
Olga Podolich ◽  
Ievgeniia Prekrasna ◽  
Ivan Parnikoza ◽  
Tamara Voznyuk ◽  
Ganna Zubova ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Bacterial Species ◽  
Vascular Plant ◽  
South Shetland Islands ◽  
Deschampsia Antarctica ◽  
Rrna Gene ◽  
King George Island ◽  
Maritime Antarctic ◽  
Organic Input

Endophytic bacteria, recognized for their beneficial effects on plant development and adaptation, can facilitate the survival of Antarctic plants in severe environments. Here we studied endophytes of the vascular plant Deschampsia antarctica Ė. Desv. from two distantly located regions in the maritime Antarctic: King George Island (South Shetland Islands) and Galindez Island (Argentine Islands). Bacterial group-specific PCR indicated presence of Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Cytophaga-Flavobacteria and Actinobacteria in root and leaf endosphere of D. antarctica sampled at four distinct sites of both locations. The diversity of endophytic bacteria was significantly higher in the leaves compared to the roots in plants from Galindez Island. Similarly, the diversity of endophytes was higher in the leaves rather than roots of plants from the King George Island. Twelve bacterial species were isolated from roots of D. antarctica of Galindez Island (the Karpaty Ridge and the Meteo Point) and identified by sequencing the 16S rRNA gene. Isolates were dominated by the Pseudomonas genus, followed by the genera Bacillus and Micrococcus. The vast majority of the isolates exhibited cellulase and pectinase activities, however, Bacillus spp. expressed neither of them, suggesting lack of genetic flow of these traits in endophytic bacilli in the maritime Antarctic. Pseudomonas sp. IMBG305 promoted an increase in the leaf number in most of the treated plant genotypes when compared with non-inoculated plants, and a rapid vegetation period of D. antarctica cultured in vitro, albeit the length of leaves in the treated plants was significantly lower, and flavonoid content leveled off in all treated plants. D. antarctica is known to develop diverse ecotypes with regard to ecological conditions, such as organic input, moisture or wind exposition. The D. antarctica phenotype could be extended further through the endophyte colonization, since phenotypic changes were observed in the inoculated D. antarcticaplants grown in vitro in our study. Herewith, endophytes can contribute to plant phenotypic plasticity, potentially beneficial for adaptation of D. antarctica.

scholarly journals First record of the endophytic bacteria of Deschampsia antarctica E. Desv. from two distant localities of the maritime Antarctica

2019 ◽  
Author(s):  
O. Podolich ◽  
I. Parnikoza ◽  
T. Voznyuk ◽  
G. Zubova ◽  
I. Zaets ◽  
...  
Keyword(s):  
Endophytic Bacteria ◽  
Vascular Plant ◽  
First Record ◽  
Deschampsia Antarctica ◽  
Rrna Gene ◽  
King George Island ◽  
Maritime Antarctica ◽  
Pcr Screening ◽  
Specific Pcr ◽  
The 16S Rrna Gene

AbstractThe vascular plant Deschampsia antarctica samples were collected for endophytic bacteria study from two regions in the maritime Antarctic 400 km distant from one another: Point Thomas oasis (King George Island) and Argentine Islands (Galindez Island). The endophytes were isolated from roots and leaves of D. antarctica, cultivated and identified by using a partial sequencing of the 16S rRNA gene served as a phylomarker. Endophyte isolates from two sites of Galindez Island were represented mainly by Pseudomonas species and by Gammaproteobacteria, Firmicutes and Actinobacteria. The vast majority of the isolates had specific for endophytes cellulase and pectinase activities, however, Bacillus spp. did not express both activities. A group-specific PCR screening at the four sites of Galindez Island and two sites of King George Island, indicated Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Firmicutes, Cytophaga-Flavobacteria and Actinobacteria. Notably, the number of endophytic bacteria taxa was significantly larger in leaves than in roots of plants.

The impacts of deglaciation and human activity on the taxonomic structure of prokaryotic communities in Antarctic soils on King George Island

2018 ◽  
Vol 30 (5) ◽  
pp. 278-288 ◽  
Author(s):  
E.V. Pershina ◽  
E.A. Ivanova ◽  
E.V. Abakumov ◽  
E.E. Andronov
Keyword(s):  
Bacterial Species ◽  
Taxonomic Composition ◽  
South Shetland Islands ◽  
Soil Microbiome ◽  
Taxonomic Structure ◽  
Rrna Gene ◽  
King George Island ◽  
Antarctic Soils ◽  
Operational Taxonomic Units ◽  
Taxonomic Analysis

AbstractThe soil microbiome was investigated at environmentally distinct locations on King George Island in the South Shetland Islands (Antarctic Peninsula) using 16 S rRNA gene pyrosequencing. The taxonomic composition of the soil prokaryotes (bacteria and archaea) was evaluated at three sites representing human-disturbed soils (Bellingshausen Station) and soils undergoing different stages of deglaciation (fresh and old moraines located near Ecology Glacier). The taxonomic analysis revealed 20 bacterial and archaeal phyla, among which Proteobacteria (29.6%), Actinobacteria (25.3%), Bacteroidetes (15.8%), Cyanobacteria (11.2%), Acidobacteria (4.9%) and Verrucomicrobia (4.5%) comprised most of the microbiome. In a beta-diversity analysis, the samples formed separate clusters. The Bellingshausen Station samples were characterized by an increased amount ofNostocsp. andJanibactersp. Although the deglaciation history had less of an effect on the soil microbiome, the early stages of deglaciation (Sample 1) had a higher proportion of bacteria belonging to the families Xanthomonadaceae, Sphingomonadaceae and Nocardioidaceae, whereas the older moraines (Sample 2) were enriched with Chthoniobacteriacae and N1423WL. Solirubrobacteriales, Gaiellaceae and Chitinophagaceae bacteria were present in both stages of deglaciation, characterized by genus-level differences. Taxonomic analysis of the abundant operational taxonomic units (OTUs) revealed both endemic (Marisediminicola antarctica,Hymenobacter glaciei) and cosmopolitan bacterial species in the microbiomes.

scholarly journals Pseudomonas fildesensis sp. nov., a psychrotolerant bacterium isolated from Antarctic soil of King George Island, South Shetland Islands

2020 ◽  
Vol 70 (5) ◽  
pp. 3255-3263 ◽  
Author(s):  
Maria S. Pavlov ◽  
Felipe Lira ◽  
José Luis Martinez ◽  
Jorge Olivares-Pacheco ◽  
Sergio H. Marshall
Keyword(s):  
16S Rrna ◽  
Type Species ◽  
Bacterial Species ◽  
Housekeeping Genes ◽  
South Shetland Islands ◽  
Rrna Gene ◽  
King George Island ◽  
Content Type ◽  
Link Type ◽  
Pseudomonas Veronii

The strain KG01T was isolated from a soil sample from King George Island, Antarctica. Cells of KG01T are rod-shaped and motile by means of multiple polar flagella. The absence of arginine dihydrolase activity could be a key feature to readily distinguish KG01T from its closest phylogenetic relative species. The main fatty acids of the strain include summed feature 3 (C16 : 1 ω7c and/or C15 : 0 iso 2-OH), C16 : 0 and C18 : 1 ω7c. Phylogenetic analysis based on the 16S rRNA gene sequence and on a multilocus sequence analysis (MLSA) using housekeeping genes (16S rRNA, rpoB, rpoD, gyrB) were carried out. These analyses allowed us to include the strain within the Pseudomonas fluorescens group, presenting the highest similarity of multilocus sequence with Pseudomonas veronii LMG 17761T (96.67 %). The genome of KG01T was sequenced and in silico compared with genomes of the most closely related species of the P. fluore scens group. The average nucleotide identity (ANIb) and average amino acid identity (AAI) values of the species phylogenetically closest to KG01T were less than 95–96 %, threshold currently accepted to define strain as belonging to a bacterial species, the highest scores being those to Pseudomonas veronii LMG 17761T (87.98 %) and Pseudomonas marginalis ICMP 3553T (91.90 %). Therefore, the phenotypic and genotypic analyses results, allow us to propose that KG01T represents a member of a novel species of the genus Pseudomonas , for which the name Pseudomonas fildesensis is proposed, and KG01T (=CECT 9084T;=DSM 102036T) is established as the type strain .

Bacterial endosymbiont inhabiting Leucaena leucocephala leaves and their antioxidant and antidiabetic potential

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sridevi Chigurupati ◽  
Shantini Vijayabalan ◽  
Kesavanarayanan Krishnan Selvarajan ◽  
Ahmad Alhowail ◽  
Fatema Kauser
Keyword(s):  
Free Radical ◽  
Crude Extract ◽  
Leucaena Leucocephala ◽  
Endophytic Bacteria ◽  
Radical Scavenging ◽  
16S Rrna Gene Sequencing ◽  
Free Radical Scavenging ◽  
Rrna Gene ◽  
Standard Drug

AbstractObjectivesResearch on endosymbionts is emerging globally and is considered as a potential source of bioactive phytochemicals. The present study examines the antioxidant and antidiabetic of the endophytic crude extract isolated from Leucaena leucocephala leaves.MethodsEndophytic bacteria were isolated from the leaves of L. leucocephala and 16S rRNA gene sequencing was used to establish their identity. The in vitro antioxidant effect of endophytic crude extract (LL) was evaluated using 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) free radical scavenging methods. The in vitro antidiabetic properties of LL were evaluated using α-amylase and α-glucosidase enzyme inhibition assay.ResultsThe isolated endophytic bacteria were identified as Cronobacter sakazakii. LL displayed potent free radical scavenging effect against ABTS and DPPH radicals with an inhibitory concentration 50% (IC50) value of 17.49 ± 0.06 and 11.3 ± 0.1 μg/mL respectively. LL exhibited α-amylase and α-glucosidase inhibition with an IC50 value of 23.3 ± 0.08 and 23.4 ± 0.1 μg/mL respectively compared to the standard drug (acarbose). Both glucose loaded normoglycemic rats and STZ induced diabetic rats treated with LL (200 mg/kg) exhibited a considerable reduction in blood glucose levels p<0.01 after 8 h of treatment when compared to normal and diabetic control rats respectively.ConclusionsThus, the study shows that LL has a wellspring of natural source of antioxidants, and antidiabetic agents and phytoconstituents present in endophytes could be the rich source for bioactive compounds.

Periphyton diversity in two different Antarctic lakes assessed using metabarcoding

2021 ◽  
pp. 1-9
Author(s):  
Paulo E.A.S. Câmara ◽  
Láuren M.D. De Souza ◽  
Otávio Henrique Bezerra Pinto ◽  
Peter Convey ◽  
Eduardo T. Amorim ◽  
...  
Keyword(s):  
Dna Sequences ◽  
High Throughput Sequencing ◽  
Shannon Index ◽  
South Shetland Islands ◽  
King George Island ◽  
Deception Island ◽  
Maritime Antarctic ◽  
Shetland Islands ◽  
Antarctic Lakes ◽  
Significant Difference

Abstract Antarctic lakes have generally simple periphyton communities when compared with those of lower latitudes. To date, assessment of microbial diversity in Antarctica has relied heavily on traditional direct observation and cultivation methods. In this study, sterilized cotton baits were left submerged for two years in two lakes on King George Island and Deception Island, South Shetland Islands (Maritime Antarctic), followed by assessment of diversity by metabarcoding using high-throughput sequencing. DNA sequences of 44 taxa belonging to four kingdoms and seven phyla were found. Thirty-six taxa were detected in Hennequin Lake on King George Island and 20 taxa were detected in Soto Lake on Deception Island. However, no significant difference in species composition was detected between the two assemblages (Shannon index). Our data suggest that metabarcoding provides a suitable method for the assessment of periphyton biodiversity in oligotrophic Antarctic lakes.

scholarly journals Genome Sequence of Pseudomonas sp. Strain LAP_36, A Rhizosphere Bacterium Isolated from King George Island, Antarctica

2021 ◽  
Vol 10 (48) ◽  
Author(s):  
Sarah Mederos da Silveira ◽  
Sheila da Silva ◽  
Andrew Macrae ◽  
Rommel T. J. Ramos ◽  
Fabrício A. Araújo ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Draft Genome ◽  
Gc Content ◽  
South Shetland Islands ◽  
Deschampsia Antarctica ◽  
King George Island ◽  
Protein Coding ◽  
Content Type ◽  
Shetland Islands ◽  
Rhizosphere Bacterium

Pseudomonas sp. strain LAP_36 was isolated from rhizosphere soil from Deschampsia antarctica on King George Island, South Shetland Islands, Antarctica. Here, we report on its draft genome sequence, which consists of 8,794,771 bp with 60.0% GC content and 8,011 protein-coding genes.

Juncus bufonius, a new non-native vascular plant in King George Island, South Shetland Islands

2012 ◽  
Vol 25 (3) ◽  
pp. 385-386 ◽  
Author(s):  
Marely Cuba-Díaz ◽  
J. Max Troncoso ◽  
Cristian Cordero ◽  
Victor L. Finot ◽  
Mauricio Rondanelli-Reyes
Keyword(s):  
Vascular Plant ◽  
South Shetland Islands ◽  
King George Island ◽  
Shetland Islands

scholarly journals Two additions to the moss flora of the South Shetland Islands in the maritime Antarctic

2018 ◽  
Vol 87 (4) ◽  
Author(s):  
Mariusz Wierzgoń ◽  
Tomasz Suchan ◽  
Michał Ronikier
Keyword(s):  
South Shetland Islands ◽  
King George Island ◽  
Maritime Antarctic ◽  
The South ◽  
Shetland Islands ◽  
Bay Area ◽  
Leading Position ◽  
Glacial Cover ◽  
The Antarctic ◽  
First Time

<em>Tortella fragilis</em> (Drumm.) Limpr. (Pottiaceae) and <em>Bryum nivale</em> Müll. Hal. (Bryaceae) are recorded for the first time from the South Shetland Islands in the northern maritime Antarctic. They were discovered in the Admiralty Bay area on King George Island, the largest island of this archipelago. The two species are briefly characterized morphologically, their habitats are described, and their distribution in the Antarctic is mapped. Discovery of these species has increased the documented moss flora of King George Island to 67 species, strengthening it in the leading position among individual areas with the richest diversity of moss flora in Antarctica. Likewise, <em>T. fragilis</em> and <em>B. nivale</em> represent remarkable additions to the moss flora of the South Shetland Islands, which currently consists of 92 species and one variety, making this archipelago by far the richest bryofloristically amongst large geographic regions of the Antarctic. Comparison of recent (2018) and old (1985) photographs revealed a significant retreat of glacial cover and suggests that the collection site was likely opened for colonization only within the last several decades. The record of <em>T. fragilis</em> is biogeographically relevant, and constitutes an intermediate site between the species’ occurrences in the Antarctic Peninsula and southern South America. The present record of <em>B. nivale</em> is the fourth discovery of the species worldwide, which may be helpful for the future designation of the distribution of this extremely rare species.

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