https://nova.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46776 Wed 30 Nov 2022 13:21:41 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:54089 Wed 28 Feb 2024 15:38:05 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:55617 Tue 11 Jun 2024 14:47:00 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44763 Pseudomonas is a large and diverse genus of Gammaproteobacteria. To provide a framework for discovery of evolutionary and taxonomic relationships of these bacteria, we compared the genomes of type strains of 163 species and 3 additional subspecies of Pseudomonas, including 118 genomes sequenced herein. A maximum likelihood phylogeny of the 166 type strains based on protein sequences of 100 single-copy orthologous genes revealed thirteen groups of Pseudomonas, composed of two to sixty three species each. Pairwise average nucleotide identities and alignment fractions were calculated for the data set of the 166 type strains and 1224 genomes of Pseudomonas available in public databases. Results revealed that 394 of the 1224 genomes were distinct from any type strain, suggesting that the type strains represent only a fraction of the genomic diversity of the genus. The core genome of Pseudomonas was determined to contain 794 genes conferring primarily housekeeping functions. The results of this study provide a phylogenetic framework for future studies aiming to resolve the classification and phylogenetic relationships, identify new gene functions and phenotypes, and explore the ecological and metabolic potential of the Pseudomonas spp.]]> Tue 08 Nov 2022 11:16:28 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50086 Thu 13 Jul 2023 10:36:19 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:53775 Mon 15 Jan 2024 10:09:33 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:38846 Raphidiopsis raciborskii is an invasive bloom-forming cyanobacteria with the flexibility to utilize atmospheric and fixed nitrogen. Since nitrogen-fixation has a high requirement for iron as an ezyme cofactor, we hypothesize that iron availability would determine the success of the species under nitrogen-fixing conditions. This study compares the proteomic response of cylindrospermopsin-producing and non-toxic strains of R. racibroskii to reduced iron concentrations, under nitrogen-fixing conditions, to examine any strain-specific adaptations that might increase fitness under these conditions. We also compared their proteomic responses at exponential and stationary growth phases to capture the changes throughout the growth cycle. Overall, the toxic strain was more competitive under Fe-starved conditions during exponential phase, with upregulated growth and transport-related proteins. The non-toxic strain showed reduced protein expression across multiple primary metabolism pathways. We propose that the increased expression of porin proteins during the exponential growth phase enables toxic strains to persist under Fe-starved conditions with this ability providing a potential explanation for the increased fitness of cylindrospermoipsin-producing strains during unfavourable environmental conditions.]]> Mon 06 May 2024 13:15:09 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46545 Fri 25 Nov 2022 11:19:25 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:34852 Fri 20 May 2022 15:28:54 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:49139 Fri 05 May 2023 12:00:04 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:35132 Raphidiopsis raciborskii is of environmental and social concern in view of its toxicity, bloom‐forming characteristics and increasingly widespread occurrence. However, while availability of macronutrients and micronutrients such as N and Fe are critically important for the growth and metabolism of this organism, the physiological response of toxic and non‐toxic strains of R. raciborskii to varying Fe and N availabilities remains unclear. By determining physiological parameters as a function of Fe and N availability, we demonstrate that R. raciborskii growth and N₂‐fixing activity are facilitated at higher Fe availability under N₂‐limited conditions with faster growth of the CS‐506 (cylindrospermopsin‐producing) strain compared with that of CS‐509 (the non‐toxic) strain. Radiolabelled Fe uptake assays indicated that R. raciborskii acclimated under Fe‐limited conditions acquires Fe at significantly higher rates than under Fe replete conditions, principally via unchelated Fe(II) generated as a result of photoreduction of complexed Fe(III). While N₂‐fixation of both strains occurred during both day and night, the CS‐506 strain overall exhibited higher N₂‐fixing and Fe uptake rates than the CS‐509 strain under N‐deficient and Fe‐limited conditions. The findings of this study highlight that Fe availability is of significance for the ecological advantage of CS‐506 over CS‐509 in N‐deficient freshwaters.]]> Fri 03 Apr 2020 12:05:38 AEDT ]]>