scholarly journals Extensive Diversity of Ionizing-Radiation-Resistant Bacteria Recovered from Sonoran Desert Soil and Description of Nine New Species of the Genus Deinococcus Obtained from a Single Soil Sample

2005 ◽  
Vol 71 (9) ◽  
pp. 5225-5235 ◽  
Author(s):  
Fred A. Rainey ◽  
Keren Ray ◽  
Margarida Ferreira ◽  
Bridget Z. Gatz ◽  
M. Fernanda Nobre ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Soil Sample ◽  
Sonoran Desert ◽  
Desert Soil ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Culturable Bacteria ◽  
Bacterial Isolates ◽  
Arid Soil ◽  
Radiation Resistant

ABSTRACT The ionizing-radiation-resistant fractions of two soil bacterial communities were investigated by exposing an arid soil from the Sonoran Desert and a nonarid soil from a Louisiana forest to various doses of ionizing radiation using a 60Co source. The numbers of surviving bacteria decreased as the dose of gamma radiation to which the soils were exposed increased. Bacterial isolates surviving doses of 30 kGy were recovered from the Sonoran Desert soil, while no isolates were recovered from the nonarid forest soil after exposure to doses greater than 13 kGy. The phylogenetic diversities of the surviving culturable bacteria were compared for the two soils using 16S rRNA gene sequence analysis. In addition to a bacterial population that was more resistant to higher doses of ionizing radiation, the diversity of the isolates was greater in the arid soil. The taxonomic diversity of the isolates recovered was found to decrease as the level of ionizing-radiation exposure increased. Bacterial isolates of the genera Deinococcus, Geodermatophilus, and Hymenobacter were still recovered from the arid soil after exposure to doses of 17 to 30 kGy. The recovery of large numbers of extremely ionizing-radiation-resistant bacteria from an arid soil and not from a nonarid soil provides further ecological support for the hypothesis that the ionizing-radiation resistance phenotype is a consequence of the evolution of other DNA repair systems that protect cells against commonly encountered environmental stressors, such as desiccation. The diverse group of bacterial strains isolated from the arid soil sample included 60 Deinococcus strains, the characterization of which revealed nine novel species of this genus.

Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert

2013 ◽  
Vol 55 (1) ◽  
pp. 135-140 ◽  
Author(s):  
Li Zhi-Han Yu ◽  
Xue-Song Luo ◽  
Ming Liu ◽  
Qiaoyun Huang
Keyword(s):  
Ionizing Radiation ◽  
Resistant Bacteria ◽  
Taklimakan Desert ◽  
The Taklimakan Desert ◽  
Radiation Resistant

scholarly journals Isolation and Identification of Resistant Bacteria from Petroleum Producing Vicinity by Gene Amplification and Sequencing

2021 ◽  
pp. 1-8
Author(s):  
O. Aleruchi ◽  
O. Obire
Keyword(s):  
16S Rrna ◽  
Phylogenetic Study ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Bacterial Isolates ◽  
Antibiotic Resistant Bacteria ◽  
Isolation And Identification ◽  
Antibiotic Resistant ◽  
Disinfection Process ◽  
Adaptive Mechanisms

This investigation focuses on molecular identification of antibiotic resistant bacteria isolated from petroleum producing vicinity using 16S rRNA sequencing based technique. The bacterial 16s rRNA gene sequences were amplified using polymerase chain reaction, sequenced,  characterized and compared by using primers which has been compared to national center for biotechnology information (NCBI) sequence database. The presence of the plasmid mediated antibiotic resistance determinants CTX-M and QNRB genes in the bacterial isolates were analyzed. A total of four bacterial isolates that were resistant to all the antibiotic agents used were identified molecularly. The BLAST results showed 100 % similarity and phylogenetic study indicated that the genes were evolutionarily related to Morganella morganii, Pseudomonas xiamenensis, Chryseobacterium cucumeris and Staphylococcus sp., respectively. The genes obtained were submitted to the NCBI gene bank and were assigned accession number; MN094330, MN094331, MN094332 and MN094333, respectively. CTX-M and QNRB genes were however absent in the bacterial isolates. The result identified some peculiar abilities of the bacterial isolates to be resistant to antibiotics and suggests a correlation with resistance and hydrocarbon utilizing bacteria. The level of resistance could be as a result of the disinfection process during wastewater treatment procedure or the same adaptive mechanisms possessed by the isolates to control the hydrocarbon concentration in their cell. The study also clearly indicates that these wastewaters, when discharged into the environment directly may pose a risk for the spread of antibiotic resistant bacteria.

Production of quorum-sensing-related signal molecules by epiphytic bacteria inhabiting wheat heads

2006 ◽  
Vol 52 (5) ◽  
pp. 411-418 ◽  
Author(s):  
Shigenobu Yoshida ◽  
Linda L Kinkel ◽  
Hirosuke Shinohara ◽  
Nobutaka Numajiri ◽  
Syuntaro Hiradate ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Population Size ◽  
Signal Molecules ◽  
Rrna Gene ◽  
Culturable Bacteria ◽  
Bacterial Isolates ◽  
16S Rrna Gene Sequences ◽  
Pantoea Ananatis ◽  
Signal Molecule ◽  
Layer Chromatography

The production of quorum-sensing-related signal molecules (QSRMs) among culturable bacteria comprising the community on wheat heads was investigated. The taxonomic position of 186 bacterial isolates obtained from ten heads was inferred based on 16S rRNA gene sequences, and their QSRM production was determined using two bioreporter strains of N-acylhomoserine lactones. Approximately 33% of isolates produced QSRMs, though the proportion of QSRM-producing isolates on a wheat head was significantly negatively correlated with population size. Most of the producing isolates were Pantoea species, most commonly Pantoea ananatis. Furthermore, the proportion of Pantoea ananatis that produced QSRMs was significantly negatively correlated with the number of bacterial genera (community richness) on each head. Finally, community richness was positively correlated with population size. Qualitative analysis using thin-layer-chromatography revealed that the QSRMs of Pantoea isolates were composed of at least two compounds. This is the first report indicating that Pantoea ananatis isolates inhabiting wheat heads are capable of producing QSRMs. QSRM production by Pantoea spp. may contribute to the predominance of this genus on wheat heads, particularly at relatively low population densities and community diversity.Key words: quorum sensing, signal molecule, epiphyte, wheat head, Pantoea spp.

scholarly journals Basal DNA repair machinery is subject to positive selection in ionizing-radiation-resistant bacteria

BMC Genomics ◽  
2008 ◽  
Vol 9 (1) ◽  
pp. 297 ◽  
Author(s):  
Haïtham Sghaier ◽  
Kaïs Ghedira ◽  
Alia Benkahla ◽  
Insaf Barkallah
Keyword(s):  
Dna Repair ◽  
Ionizing Radiation ◽  
Positive Selection ◽  
Resistant Bacteria ◽  
Radiation Resistant

scholarly journals Marine cyanolichens from different littoral zones are associated with distinct bacterial communities

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5208 ◽  
Author(s):  
Nyree J. West ◽  
Delphine Parrot ◽  
Claire Fayet ◽  
Martin Grube ◽  
Sophie Tomasi ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Littoral Zone ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Moderately Thermophilic ◽  
Culture Independent ◽  
Radiation Resistant ◽  
Bacteroidetes Phylum ◽  
And Function ◽  
The Impact

The microbial diversity and function of terrestrial lichens have been well studied, but knowledge about the non-photosynthetic bacteria associated with marine lichens is still scarce. 16S rRNA gene Illumina sequencing was used to assess the culture-independent bacterial diversity in the strictly marine cyanolichen speciesLichina pygmaeaandLichina confinis, and the maritime chlorolichen speciesXanthoria aureolawhich occupy different areas on the littoral zone. Inland terrestrial cyanolichens from Austria were also analysed as for the marine lichens to examine further the impact of habitat/lichen species on the associated bacterial communities. TheL. confinisandL. pygmaeacommunities were significantly different from those of the maritimeXanthoria aureolalichen found higher up on the littoral zone and these latter communities were more similar to those of the inland terrestrial lichens. The strictly marine lichens were dominated by the Bacteroidetes phylum accounting for 50% of the sequences, whereas Alphaproteobacteria, notablySphingomonas, dominated the maritime and the inland terrestrial lichens. Bacterial communities associated with the twoLichinaspecies were significantly different sharing only 33 core OTUs, half of which were affiliated to the Bacteroidetes generaRubricoccus,TunicatimonasandLewinella, suggesting an important role of these species in the marineLichinalichen symbiosis. Marine cyanolichens showed a higher abundance of OTUs likely affiliated to moderately thermophilic and/or radiation resistant bacteria belonging to the Phyla Chloroflexi, Thermi, and the families Rhodothermaceae and Rubrobacteraceae when compared to those of inland terrestrial lichens. This most likely reflects the exposed and highly variable conditions to which they are subjected daily.

Multiple-Stress Tolerance of Ionizing Radiation-Resistant Bacterial Isolates Obtained from Various Habitats: Correlation Between Stresses

2006 ◽  
Vol 54 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Manish Shukla ◽  
Ruchi Chaturvedi ◽  
Dhruti Tamhane ◽  
Pranav Vyas ◽  
G. Archana ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Stress Tolerance ◽  
Bacterial Isolates ◽  
Multiple Stress ◽  
Radiation Resistant ◽  
Multiple Stress Tolerance

scholarly journals Marine cyanolichens from different littoral zones are associated with distinct bacterial communities

2017 ◽  
Author(s):  
Nyree J. West ◽  
Delphine Parrot ◽  
Claire Fayet ◽  
Martin Grube ◽  
Sophie Tomasi ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Littoral Zone ◽  
Resistant Bacteria ◽  
Rrna Gene ◽  
Moderately Thermophilic ◽  
Culture Independent ◽  
Radiation Resistant ◽  
Bacteroidetes Phylum ◽  
And Function ◽  
The Impact

AbstractThe microbial diversity and function of terrestrial lichens has been well studied, but knowledge about the non-photosynthetic bacteria associated with marine lichens is still scarce. 16S rRNA gene Illumina sequencing was used to assess the culture-independent bacterial diversity in the strictly marine cyanolichen speciesLichina pygmaeaandLichina confinis, and the maritime chlorolichen speciesXanthoria aureolawhich occupy different areas on the littoral zone. Inland terrestrial cyanolichens from Austria were also analysed as for the marine lichens to examine further the impact of habitat/lichen species on the associated bacterial communities. TheL. confinisandL. pygmaeacommunities were significantly different from those of the maritimeXanthoria aureolalichen found higher up on the littoral zone and these latter communities were more similar to those of the inland terrestrial lichens. The strictly marine lichens were dominated by the Bacteroidetes phylum accounting for 50% of the sequences, whereas Alphaproteobacteria, notablySphingomonas, dominated the maritime and the inland terrestrial lichens. Bacterial communities associated with the twoLichinaspecies were significantly different sharing only 33 core OTUs, half of which were affiliated to the Bacteroidetes generaRubricoccus, TunicatimonasandLewinella, suggesting an important role of these species in the marineLichinalichen symbiosis. Marine cyanolichens showed a higher abundance of OTUs likely affiliated to moderately thermophilic and/or radiation resistant bacteria belonging to the Phyla Chloroflexi, Thermi, and the families Rhodothermaceae and Rubrobacteraceae when compared to those of inland terrestrial lichens. This most likely reflects the exposed and highly variable conditions to which they are subjected daily.

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