Biogeographical and phylogenetic boundaries of the specialised metabolism of pseudonocardia from marine origin
Multidrug-resistant pathogens have become a global threat. In this context, filamentous actinomycetes have been proven to be an exceptional source of antimicrobial metabolites. In particular, rare actinomycetes isolated from marine environments have been proposed as a potential source of yet untappe...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | unknown |
| Published: |
2022
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| Online Access: | https://doi.org/10.48730/w08e-3m22 https://stax.strath.ac.uk/concern/theses/707958206 |
| Summary: | Multidrug-resistant pathogens have become a global threat. In this context, filamentous actinomycetes have been proven to be an exceptional source of antimicrobial metabolites. In particular, rare actinomycetes isolated from marine environments have been proposed as a potential source of yet untapped specialised metabolites. In this study, two novel species, Pseudonocardia abyssalis sp. nov. and Pseudonocardia oceani sp. nov., isolated from deep Southern Ocean sediments are described, both in terms of their phenotypic and genomic characterization. Furthermore, the genomic architecture, with a focus on Biosynthetic Gene Clusters (BGC), across eight strains belonging to the two novel species was investigated. As a result, a total of 13 Gene Cluster Families (GCF) were identified, of which six GCFs comprise BGCs from both species, and one was annotated specifically of each species. Following genome analysis, a comparative mass-spectrometry based metabolomics analysis was carried out, including phylogenetically closely-related non-marine species, as well as other Pseudonocardia strains isolated from different marine environments. Then, genomics and metabolomics data were correlated through NPLinker, an unsupervised method for integrating paired omics data. As a result, it was demonstrated that the BGC evolution and distribution across strains is mainly shaped by phylogeny over any biogeographical pattern.Furthermore, metabolomics and genome mining tools were used to assess the role of the specialised metabolites on interactions between members of the Pseudonocardia genus isolated from different marine environments. To this end, using challenge bioassays, antagonist interaction between nine Pseudonocardia spp. isolated from marine sediments and two non-marine species was examined and correlated to the strains' phylogeny and their metabolomics profile. To understand the spatial dynamics, matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry imaging (MSI) was used to examine in situ species chemical ... |
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