Two novel cyclic peptides are key components of the antimicrobial activity of the Greenlandic isolate Pseudomonas sp. In5

TY - ABST

T1 - Two novel cyclic peptides are key components of the antimicrobial activity of the Greenlandic isolate Pseudomonas sp. In5

AU - Hennessy, Rosanna Catherine

AU - Phippen, Christopher

AU - Nielsen, Kristian F.

AU - Michelsen, Charlotte Frydenlund

AU - Olsson, Stefan

AU - Stougaard, Peter

PY - 2015

Y1 - 2015

N2 - Pseudomonas sp. are a rich source of secondary metabolites including bioactive non-ribosomal peptides (NRPs) and polyketides. NRPs are synthesised in large assembly lines by multi-domain modular enzymes known as NRP-synthetases (NRPS). Nunamycin and nunapeptin are two cyclic NRPs synthesised by the Greenlandic isolate Pseudomonas sp. In5. Nunamycin shows antifungal activity against the basidiomycete Rhizoctonia solani whereas the only partially structure elucidated nunapeptin appears most active against the ascomycete Fusarium graminearum and the oomycete Pythium aphanidermatum. Originally isolated from suppressive soil, Pseudomonas sp. In5 is therefore a promising potential biocontrol agent with potent activity against plant pathogens. Studies to date have shown nunamycin and nunapeptin as key components underpinning this antimicrobial activity. Current research is focussed on unravelling the regulation and antimicrobial mode of action of both peptides. Functional characterisation of the LuxR-type regulatory gene nunF by targeted knock-out and complementation resulted in the loss and gain of both antimicrobial activity and peptide synthesis respectively. Located downstream of the nunamycin biosynthetic genes, nunF shows homology to syrF from P. syringae pv. syringae involved in the regulation of the antifungal peptide syringomycin. These results show that nunF is a key component of antimicrobial activity and synthesis of nunamycin and nunapeptin.

AB - Pseudomonas sp. are a rich source of secondary metabolites including bioactive non-ribosomal peptides (NRPs) and polyketides. NRPs are synthesised in large assembly lines by multi-domain modular enzymes known as NRP-synthetases (NRPS). Nunamycin and nunapeptin are two cyclic NRPs synthesised by the Greenlandic isolate Pseudomonas sp. In5. Nunamycin shows antifungal activity against the basidiomycete Rhizoctonia solani whereas the only partially structure elucidated nunapeptin appears most active against the ascomycete Fusarium graminearum and the oomycete Pythium aphanidermatum. Originally isolated from suppressive soil, Pseudomonas sp. In5 is therefore a promising potential biocontrol agent with potent activity against plant pathogens. Studies to date have shown nunamycin and nunapeptin as key components underpinning this antimicrobial activity. Current research is focussed on unravelling the regulation and antimicrobial mode of action of both peptides. Functional characterisation of the LuxR-type regulatory gene nunF by targeted knock-out and complementation resulted in the loss and gain of both antimicrobial activity and peptide synthesis respectively. Located downstream of the nunamycin biosynthetic genes, nunF shows homology to syrF from P. syringae pv. syringae involved in the regulation of the antifungal peptide syringomycin. These results show that nunF is a key component of antimicrobial activity and synthesis of nunamycin and nunapeptin.

M3 - Conference abstract for conference

T2 - CMC Symposium

Y2 - 2 October 2015

ER -