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Microbial Consortium Associated with the Antarctic Marine Ciliate Euplotes focardii: An Investigation from Genomic Sequences.

Pucciarelli S, Devaraj RR, Mancini A, Ballarini P, Castelli M, Schrallhammer M, Petroni G, Miceli C - Microb. Ecol. (2015)

Bottom Line: Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in "transmembrane transporter activity" and "oxidoreductase activity".We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins.To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, 62032, Italy, sandra.pucciarelli@unicam.it.

ABSTRACT
We report the characterization of the bacterial consortium associated to Euplotes focardii, a strictly psychrophilic marine ciliate that was maintained in laboratory cultures at 4 °C after its first isolation from Terra Nova Bay, in Antarctica. By Illumina genome analyser, we obtained 11,179 contigs of potential prokaryotic origin and classified them according to the NCBI's prokaryotic attributes table. The majority of these sequences correspond to either Bacteroidetes (16 %) or Proteobacteria (78 %). The latter were dominated by gamma- (39 %, including sequences related to the pathogenic genus Francisella), and alpha-proteobacterial (30 %) sequences. Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in "transmembrane transporter activity" and "oxidoreductase activity". Furthermore, we identified genes that encode for enzymes involved in the catabolism of complex substance for energy reserves. We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins. Antibiotic treatments of E. focardii cultures delayed the cell division of the ciliate. To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition. Furthermore, our results suggest that these bacteria may have a more general role in E. focardii survival in its natural cold and oxidative environment.

No MeSH data available.


Related in: MedlinePlus

Analysis of E. focardii cells previously exposed to antibiotic treatments. a Agarose gel of PCR reaction performed on purified genomic DNA from E. focardii cells without antibiotics (lane 1) and after treatment with 103 U/ml of penicillin-G (lane 2), 103 U/ml of streptomycin (lane 3), and with a mix containing 103 U/ml of both penicillin-G and streptomycin (lane 4), using as primers a mix of oligonucleotides that amplify a fragment of 170 bp of the 16S rDNA sequences. b Growth rate of untreated E. focardii cells associated to their long lasting microbial consortium and E. focardii cells preliminary treated with a mix containing 103 U/ml of both penicillin-G and streptomycin for 15 days to deplete the microbial consortium associated to the ciliate. The cells were counted for 20 days
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Fig6: Analysis of E. focardii cells previously exposed to antibiotic treatments. a Agarose gel of PCR reaction performed on purified genomic DNA from E. focardii cells without antibiotics (lane 1) and after treatment with 103 U/ml of penicillin-G (lane 2), 103 U/ml of streptomycin (lane 3), and with a mix containing 103 U/ml of both penicillin-G and streptomycin (lane 4), using as primers a mix of oligonucleotides that amplify a fragment of 170 bp of the 16S rDNA sequences. b Growth rate of untreated E. focardii cells associated to their long lasting microbial consortium and E. focardii cells preliminary treated with a mix containing 103 U/ml of both penicillin-G and streptomycin for 15 days to deplete the microbial consortium associated to the ciliate. The cells were counted for 20 days

Mentions: In order to test the possible contribution of the bacterial consortium to E. focardii cold-adaptation, the viability and proliferation of E. focardii cells under laboratory conditions after treatment of the cultures with the antibiotics penicillin and/or streptomycin was analyzed. The genomic DNA from E. focardii cells was extracted after the antibiotic treatment, and PCR was performed using a mix of oligonucleotides amplifying a conserved fragment of the 16S rDNA sequence (170 bp). No PCR product was obtained in the sample from E. focardii cells treated with both antibiotics (Fig. 6a), confirming that only the treatment with both penicillin-G and streptomycin efficiently remove the bacterial consortium from E. focardii cultures. Subsequently, we analysed the growth rate of E. focardii cells after the combined treatment with the two mentioned antibiotics over a period of 20 days. E. focardii cells showed a significant lower growth rate (p value = 0.0224) with respect to the control (i.e., not previously treated with the two antibiotics; Fig. 6b). This result suggests that the bacterial consortium is not essential for the survival of E. focardii cells, but its elimination reduces cell proliferation capabilities.Fig. 6


Microbial Consortium Associated with the Antarctic Marine Ciliate Euplotes focardii: An Investigation from Genomic Sequences.

Pucciarelli S, Devaraj RR, Mancini A, Ballarini P, Castelli M, Schrallhammer M, Petroni G, Miceli C - Microb. Ecol. (2015)

Analysis of E. focardii cells previously exposed to antibiotic treatments. a Agarose gel of PCR reaction performed on purified genomic DNA from E. focardii cells without antibiotics (lane 1) and after treatment with 103 U/ml of penicillin-G (lane 2), 103 U/ml of streptomycin (lane 3), and with a mix containing 103 U/ml of both penicillin-G and streptomycin (lane 4), using as primers a mix of oligonucleotides that amplify a fragment of 170 bp of the 16S rDNA sequences. b Growth rate of untreated E. focardii cells associated to their long lasting microbial consortium and E. focardii cells preliminary treated with a mix containing 103 U/ml of both penicillin-G and streptomycin for 15 days to deplete the microbial consortium associated to the ciliate. The cells were counted for 20 days
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4494151&req=5

Fig6: Analysis of E. focardii cells previously exposed to antibiotic treatments. a Agarose gel of PCR reaction performed on purified genomic DNA from E. focardii cells without antibiotics (lane 1) and after treatment with 103 U/ml of penicillin-G (lane 2), 103 U/ml of streptomycin (lane 3), and with a mix containing 103 U/ml of both penicillin-G and streptomycin (lane 4), using as primers a mix of oligonucleotides that amplify a fragment of 170 bp of the 16S rDNA sequences. b Growth rate of untreated E. focardii cells associated to their long lasting microbial consortium and E. focardii cells preliminary treated with a mix containing 103 U/ml of both penicillin-G and streptomycin for 15 days to deplete the microbial consortium associated to the ciliate. The cells were counted for 20 days
Mentions: In order to test the possible contribution of the bacterial consortium to E. focardii cold-adaptation, the viability and proliferation of E. focardii cells under laboratory conditions after treatment of the cultures with the antibiotics penicillin and/or streptomycin was analyzed. The genomic DNA from E. focardii cells was extracted after the antibiotic treatment, and PCR was performed using a mix of oligonucleotides amplifying a conserved fragment of the 16S rDNA sequence (170 bp). No PCR product was obtained in the sample from E. focardii cells treated with both antibiotics (Fig. 6a), confirming that only the treatment with both penicillin-G and streptomycin efficiently remove the bacterial consortium from E. focardii cultures. Subsequently, we analysed the growth rate of E. focardii cells after the combined treatment with the two mentioned antibiotics over a period of 20 days. E. focardii cells showed a significant lower growth rate (p value = 0.0224) with respect to the control (i.e., not previously treated with the two antibiotics; Fig. 6b). This result suggests that the bacterial consortium is not essential for the survival of E. focardii cells, but its elimination reduces cell proliferation capabilities.Fig. 6

Bottom Line: Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in "transmembrane transporter activity" and "oxidoreductase activity".We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins.To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition.

View Article: PubMed Central - PubMed

Affiliation: School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, 62032, Italy, sandra.pucciarelli@unicam.it.

ABSTRACT
We report the characterization of the bacterial consortium associated to Euplotes focardii, a strictly psychrophilic marine ciliate that was maintained in laboratory cultures at 4 °C after its first isolation from Terra Nova Bay, in Antarctica. By Illumina genome analyser, we obtained 11,179 contigs of potential prokaryotic origin and classified them according to the NCBI's prokaryotic attributes table. The majority of these sequences correspond to either Bacteroidetes (16 %) or Proteobacteria (78 %). The latter were dominated by gamma- (39 %, including sequences related to the pathogenic genus Francisella), and alpha-proteobacterial (30 %) sequences. Analysis of the Pfam domain family and Gene Ontology term variation revealed that the most frequent terms that appear unique to this consortium correspond to proteins involved in "transmembrane transporter activity" and "oxidoreductase activity". Furthermore, we identified genes that encode for enzymes involved in the catabolism of complex substance for energy reserves. We also characterized members of the transposase and integrase superfamilies, whose role in bacterial evolution is well documented, as well as putative antifreeze proteins. Antibiotic treatments of E. focardii cultures delayed the cell division of the ciliate. To conclude, our results indicate that this consortium is largely represented by bacteria derived from the original Antarctic sample and may contribute to the survival of E. focardii in laboratory condition. Furthermore, our results suggest that these bacteria may have a more general role in E. focardii survival in its natural cold and oxidative environment.

No MeSH data available.


Related in: MedlinePlus