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Ebel, R.

Publications and source records attributed to Ebel, R..

2 recordsLinked to original sources
bioRxiv2021

Inhibition of Quorum Sensing System in Pseudomonas aeruginosa by Psammaplin A and Bisaprasin Isolated from the Marine Sponge Aplysinella rhax

Natural products isolated from marine sponges have exhibited profound bioactivity and, in some cases, serve as potent quorum sensing inhibitory agents by preventing microbial biofilm formation. In this study, the inhibitory potential of the psammaplin type compounds, psammaplin A (1) and bisaprasin (2), isolated from the marine sponge, Aplysinella rhax, was evaluated in the quorum-sensing inhibitory assay based on the Pseudomonas aeruginosa PAO1 lasB-gfp and P. aeruginosa PAO1 rhlA-gfp biosensor strains. The result indicated that psammaplin A (1) showed moderate inhibition against lasB-gfp biosensor strains but significantly inhibited the QS-gene promoters, rhlA-gfp with IC50 value at 30.69 and 2.64 M, respectively. In contrast, bisaprasin (2) displayed significant inhibition for both biosensor strains, lasB-gfp and rhlA-gfp with IC50 values at 8.70 and 8.53 M, respectively. To our knowledge, the antiquorum sensing activity of these marine-derived bromotyrosine compounds is described here for the first time. Significance and Impact of the StudyThe attention of the scientific community has been drawn to using marine sources to find novel quorum sensing inhibitors as antipathogenic drugs to combat antimicrobial resistance and pathogenesis caused by the proliferation of pathogenic bacteria mediated by the quorum sensing (QS) system. By blocking the QS signalling communication, the ability to assemble an organised community structure that enables drug resistance and production of virulence factors will be attenuated. The significance of this investigation is based on the discovery of bromotyrosine derivatives as potential new drug leads for the development of antipathogenic agents.

microbiology↗
bioRxiv2020

Iron-meditated fungal starvation by Lupine rhizosphere-associated and extremotolerant Streptomyces sp. S29 desferrioxamine production

Siderophores are iron-chelating compounds that aid iron uptake, one of the key strategies for microorganisms to carve out ecological niches in microbially diverse environments. Desferrioxamines are the principal siderophores produced by Streptomyces spp. Their biosynthesis has been well studied and as a consequence, the chemical potential of the pathway continues to expand. With all of this in mind, our study aimed to explore extremotolerant and Lupine rhizosphere-derived Streptomyces sp. S29 for its potential antifungal capabilities. Cocultivation of isolate S29 was carried out with Aspergillus niger and Botrytis cinerea, both costly fungal phytopathogens in the wine industry, to simulate their interaction within the rhizosphere. The results indicate that not only is Streptomyces sp. S29 extraordinary at producing hydroxamate siderophores but uses siderophore production as a means to starve the fungi of iron. High resolution LC-MS/MS followed by GNPS molecular networking was used to observe the datasets for desferrioxamines and guided structure elucidation of new desferrioxamine analogues. Comparing the new chemistry, using tools like molecular networking and MS2LDA, with the known biosynthesis, we show that the chemical potential of the desferrioxamine pathway has further room for exploration.

microbiology↗