scholarly journals Root-Associated Bacteria Community Characteristics of Antarctic Plants: Deschampsia antarctica and Colobanthus quitensis—a Comparison

2021 ◽  
Author(s):  
Anna Znój ◽  
Jan Gawor ◽  
Robert Gromadka ◽  
Katarzyna J. Chwedorzewska ◽  
Jakub Grzesiak
Keyword(s):  
Deschampsia Antarctica ◽  
Rrna Gene ◽  
Biolog Ecoplates ◽  
Colobanthus Quitensis ◽  
Breeding Populations ◽  
The Family ◽  
Ecological Success ◽  
Different Characteristics ◽  
High Degree ◽  
The Antarctic

Abstract Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv. are the only Magnoliophyta to naturally colonize the Antarctic region. The reason for their sole presence in Antarctica is still debated as there is no definitive consensus on how only two unrelated flowering plants managed to establish breeding populations in this part of the world. In this study, we have explored and compared the rhizosphere and root-endosphere dwelling microbial community of C. quitensis and D. antarctica specimens sampled in maritime Antarctica from sites displaying contrasting edaphic characteristics. Bacterial phylogenetic diversity (high-throughput 16S rRNA gene fragment targeted sequencing) and microbial metabolic activity (Biolog EcoPlates) with a geochemical soil background were assessed. Gathered data showed that the microbiome of C. quitensis root system was mostly site-dependent, displaying different characteristics in each of the examined locations. This plant tolerated an active bacterial community only in severe conditions (salt stress and nutrient deprivation), while in other more favorable circumstances, it restricted microbial activity, with a possibility of microbivory-based nutrient acquisition. The microbial communities of D. antarctica showed a high degree of similarity between samples within a particular rhizocompartment. The grass’ endosphere was significantly enriched in plant beneficial taxa of the family Rhizobiaceae, which displayed obligatory endophyte characteristics, suggesting that at least part of this community is transmitted vertically. Ultimately, the ecological success of C. quitensis and D. antarctica in Antarctica might be largely attributed to their associations and management of root-associated microbiota.

Leishmanicidal and antitumoral activities of endophytic fungi associated with the Antarctic angiosperms Deschampsia antarctica Desv. and Colobanthus quitensis (Kunth) Bartl.

Extremophiles ◽  
2011 ◽  
Vol 16 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Iara F. Santiago ◽  
Tânia M. A. Alves ◽  
Ana Rabello ◽  
Policarpo A. Sales Junior ◽  
Alvaro J. Romanha ◽  
...  
Keyword(s):  
Endophytic Fungi ◽  
Deschampsia Antarctica ◽  
Colobanthus Quitensis ◽  
The Antarctic

scholarly journals Robiginitomaculum antarcticum gen. nov., sp. nov., a member of the family Hyphomonadaceae, from Antarctic seawater

2007 ◽  
Vol 57 (11) ◽  
pp. 2595-2599 ◽  
Author(s):  
Kiyoung Lee ◽  
Hong Kum Lee ◽  
Tae-Hwan Choi ◽  
Jang-Cheon Cho
Keyword(s):  
New Genus ◽  
Phylogenetic Analyses ◽  
Fatty Acid Content ◽  
Salinity Range ◽  
Rrna Gene ◽  
Strictly Aerobic ◽  
The Novel ◽  
Sequence Comparisons ◽  
The Family ◽  
The Antarctic

A seawater bacterium, designated IMCC3195T, was isolated from the Antarctic coast. Cells of the novel strain were Gram-negative, rusty-coloured, strictly aerobic, chemoheterotrophic, non-budding and non-motile rods or vibrioids that possessed a thin prostheca. Based on 16S rRNA gene sequence comparisons, the novel strain was most closely related to the genera Hyphomonas (89.4–90.9 %), Maricaulis (90.1–90.4 %), Hirschia (89.0 %) and Oceanicaulis (87.9 %) of the family Hyphomonadaceae. Phylogenetic analyses also showed the Antarctic isolate to be only distantly related to the genera of stalked bacteria of marine origin in the family Hyphomonadaceae. The DNA G+C content of the novel strain was 60.3 mol% and the predominant cellular fatty acids were C18 : 1 ω7c (41.9 %), C17 : 1 ω8c (21.4 %) and C17 : 0 (14.3 %). The major quinone was Q-10. Several phenotypic and chemotaxonomic characteristics, including optimum temperature and salinity range for growth, cell morphology, pigmentation and fatty acid content, differentiated the novel strain from other related genera in the family Hyphomonadaceae. From the taxonomic evidence collected in this study, it is suggested that strain IMCC3195T (=KCCM 42687T=NBRC 103098T) represents a new genus and novel species in the family Hyphomonadaceae, for which the name Robiginitomaculum antarcticum gen. nov., sp. nov. is proposed.

scholarly journals Polar Cryoconite Associated Microbiota Is Dominated by Hemispheric Specialist Genera

2021 ◽  
Vol 12 ◽  
Author(s):  
Jasmin L. Millar ◽  
Elizabeth A. Bagshaw ◽  
Arwyn Edwards ◽  
Ewa A. Poniecka ◽  
Anne D. Jungblut
Keyword(s):  
18S Rrna Gene ◽  
The Arctic ◽  
Rrna Gene ◽  
Sequence Variant ◽  
Polar Regions ◽  
Core Group ◽  
Wide Range ◽  
The Family ◽  
Rrna Gene Sequencing ◽  
The Antarctic

Cryoconite holes, supraglacial depressions containing water and microbe-mineral aggregates, are known to be hotspots of microbial diversity on glacial surfaces. Cryoconite holes form in a variety of locations and conditions, which impacts both their structure and the community that inhabits them. Using high-throughput 16S and 18S rRNA gene sequencing, we have investigated the communities of a wide range of cryoconite holes from 15 locations across the Arctic and Antarctic. Around 24 bacterial and 11 eukaryotic first-rank phyla were observed in total. The various biotic niches (grazer, predator, photoautotroph, and chemotroph), are filled in every location. Significantly, there is a clear divide between the bacterial and microalgal communities of the Arctic and that of the Antarctic. We were able to determine the groups contributing to this difference and the family and genus level. Both polar regions contain a “core group” of bacteria that are present in the majority of cryoconite holes and each contribute >1% of total amplicon sequence variant (ASV) abundance. Whilst both groups contain Microbacteriaceae, the remaining members are specific to the core group of each polar region. Additionally, the microalgal communities of Arctic cryoconite holes are dominated by Chlamydomonas whereas the Antarctic cryoconite holes are dominated by Pleurastrum. Therefore cryoconite holes may be a global feature of glacier landscapes, but they are inhabited by regionally distinct microbial communities. Our results are consistent with the notion that cryoconite microbiomes are adapted to differing conditions within the cryosphere.

Monoglobus pectinilyticus gen. nov., sp. nov., a pectinolytic bacterium isolated from human faeces.

2020 ◽  
Author(s):  
CC Kim ◽  
WJ Kelly ◽  
ML Patchett ◽  
GW Tannock ◽  
Z Jordens ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Sequence Similarity ◽  
Middle Lamella ◽  
Rrna Gene ◽  
Gene Sequences ◽  
16S Rrna Gene Sequences ◽  
Citrus Peel ◽  
Human Faeces ◽  
The Family

© 2017 IUMS. A novel anaerobic pectinolytic bacterium (strain 14T) was isolated from human faeces. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 14T belonged to the family Ruminococcaceae, but was located separately from known clostridial clusters within the taxon. The closest cultured relative of strain 14T was Acetivibrio cellulolyticus (89.7% sequence similarity). Strain 14T shared ~99% sequence similarity with cloned 16S rRNA gene sequences from uncultured bacteria derived from the human gut. Cells were Gram-stain-positive, non-motile cocci approximately 0.6μm in diameter. Strain 14T fermented pectins from citrus peel, apple, and kiwifruit as well as carbohydrates that are constituents of pectins and hemicellulose, such as galacturonic acid, xylose, and arabinose. TEM images of strain 14T, cultured in association with plant tissues, suggested extracellular fibrolytic activity associated with the bacterial cells, forming zones of degradation in the pectin-rich regions of middle lamella. Phylogenetic and phenotypic analysis supported the differentiation of strain 14T as a novel genus in the family Ruminococcaceae. The name Monoglobus pectinilyticus gen. nov., sp. nov. is proposed; the type strain is 14T (JCM 31914T=DSM 104782T).

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