The extreme conditions of the Antarctic environment have driven the evolution of highly specialized microbial communities with unique adaptations. In this study, we characterized five Pseudomonas isolates from James Ross Island, which displayed notable taxonomic and metabolite features. Phylogenomic analysis revealed that strain P2663T occupies a distinct phylogenetic position within the Pseudomonas genus, related to species Pseudomonas svalbardensis, Pseudomonas silesiensis, Pseudomonas mucoides, Pseudomonas prosekii, and Pseudomonas gregormendelii. The novelty of five Antarctic isolates was further confirmed through analyses of housekeeping genes, ribotyping, and REP-PCR profiling. MALDI-TOF MS analysis identified 11 unique mass spectrometry signals shared by the Antarctic isolates, which were not detected in other related species. Additionally, chemotaxonomic characterization, including fatty acid composition, demonstrated similarities with related Pseudomonas species. Phenotypic assessments revealed distinctive biochemical and physiological traits. In-depth genomic analysis of strain P2663T uncovered numerous genes which could be involved in survival in extreme Antarctic conditions, including those encoding cold-shock and heat-shock proteins, oxidative and osmotic stress response proteins, and carotenoid-like pigments. Genome mining further revealed several biosynthetic gene clusters, some of which are associated with antimicrobial activity. Functional assays supported the antimicrobial capabilities of this novel species, showing antagonistic effects against clinical isolates of Pseudomonas aeruginosa, possibly mediated by tailocins (phage tail-like particles). This comprehensive polyphasic study characterized a new cold-adapted species, for which we propose the name Pseudomonas rossensis sp. nov.

• Klíčová slova
• Antarctica, Antibiotics, Antimicrobials, Cold adaptation, Inhibition, Novel species, Psychrotolerant bacteria,
• Publikační typ
• časopisecké články MeSH

The antibacterial effects of essential oils and their components (EOCs) are usually attributed to effects on membranes and metabolism. Studies of the effects of EOCs on protein expression have primarily analysed proteins larger than 10 kDa using gel electrophoresis. In the present study, we used MALDI-TOF-MS to investigate the effects of EOCs on low-molecular-weight proteins. From 297 m/z features, we identified 94 proteins with important differences in expression among untreated samples, samples treated with EOCs, and samples treated with antibiotics, peroxide, or chlorine. The targets of these treatments obviously differ, even among EOCs. In addition to ribosomal proteins, stress-, membrane- and biofilm-related proteins were affected. These findings may provide a basis for identifying new targets of essential oils and synergies with other antibiotics.

• MeSH
• antibakteriální látky metabolismus   MeSH
• Escherichia coli účinky léků   fyziologie   MeSH
• fyziologický stres * MeSH
• molekulová hmotnost MeSH
• oleje prchavé metabolismus   MeSH
• proteiny z Escherichia coli analýza   chemie   MeSH
• proteom analýza   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antibakteriální látky MeSH
• oleje prchavé MeSH
• proteiny z Escherichia coli MeSH
• proteom MeSH

The cold shock protein family consists of the transfer of the foodborne pathogen Listeria monocytogenes from 37 to 4 and -20 °C and was characterized by the sharp induction of a low molecular mass protein. This major cold shock protein ferritin-like protein (Flp) has an important role in regulation of various microbial physiological processes. Flp have a molecular mass of about 18 kDa, as observed on SDS-PAGE. The purification procedure including ammonium sulfate fractionation was used. Monospecific polyclonal antibodies raised in rabbits against the purified new Flp immunostained a single 18-kDa Flp band in extracts from different cytoplasmic proteins blotted onto nitrocellulose. A 411-bp cDNA fragment that corresponds to an internal region of an flp gene was obtained by RT-PCR. Our result indicated a surexpression of major cold shock protein and an important increase in flp mRNA amount after a downshift temperature especially at -20 °C.

• MeSH
• bakteriální proteiny biosyntéza   genetika   izolace a purifikace   MeSH
• chemická frakcionace MeSH
• chemická precipitace MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• ferritin biosyntéza   genetika   izolace a purifikace   MeSH
• králíci MeSH
• Listeria monocytogenes účinky záření   MeSH
• molekulová hmotnost MeSH
• monoklonální protilátky imunologie   MeSH
• nízká teplota * MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• protilátky bakteriální imunologie   MeSH
• síran amonný metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• western blotting MeSH
• zmrazování * MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bakteriální proteiny MeSH
• ferritin-like protein, Listeria MeSH Prohlížeč
• ferritin MeSH
• monoklonální protilátky MeSH
• protilátky bakteriální MeSH
• síran amonný MeSH