title: Bacterium-bacterium inhibitory interactions among psychrotrophic bacteria isolated from Antarctic seawater (Terra Nova Bay, Ross Sea).
abstract: One hundred and forty bacteria isolated from Antarctic seawater samples were examined for their ability to inhibit the growth of indigenous isolates and their sensitivity to antibacterial activity expressed by one another. On the basis of 16S rRNA gene sequencing and analysis, bacterial isolates were assigned to five phylogenetically different taxa, Actinobacteria, alpha and gamma subclasses of Proteobacteria, Bacillaceae, and Bacteroidetes. Twenty-one isolates (15%), predominantly Actinobacteria, exhibited antagonistic properties against marine bacteria of Antarctic origin. Members of Bacteroidetes and Firmicutes did not show any inhibitory activity. Differences were observed among inhibition patterns of single isolates, suggesting that their activity was more likely strain-specific rather than dependent on phylogenetic affiliation. A novel analysis based on network theory confirmed these results, showing that the structure of this population is probably robust to perturbations, but also that it depends strongly on the most active strains. The determination of plasmid incidence in the bacterial strains investigated revealed that there was no correlation between their presence and the antagonistic activity. The data presented here provide evidence for the antagonistic interactions within bacterial strains inhabiting Antarctic seawater and suggest the potential exploitation of Antarctic bacteria as a novel source of antibiotics.
authors: Department of Animal Biology and Marine Ecology (DBAEM), University of Messina, Messina, Italy. alogiudice@unime.it
authors: Angelina
authors: A
authors: Lo Giudice
authors: Matteo
authors: M
authors: Brilli
authors: Vivia
authors: V
authors: Bruni
authors: Maria
authors: M
authors: De Domenico
authors: Renato
authors: R
authors: Fani
authors: Luigi
authors: L
authors: Michaud
mesh_terms: D000864:Antarctic Regions; D000898:Antibiosis; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D017753:Ecosystem; D020459:Genes, rRNA; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S