Exploring the capacity of Pseudomonas syringae to produce lipopeptides in bioreactors
Résumé
Members of the P.syringae complex produce a wide variety of secondary metabolites, including lipopeptides such as syringomycins and syringopeptins which have potent antifungal activities. Wild bacterial strains often produce lipopeptides in limited quantity under culture conditions, and little research has been done to explore their production potential in bioreactors. In this study, we aimed to investigate the growing strength and the lipopeptide production potential of P. syringae strains at different bioreactor scales. First, 71 lipopeptides producing P. syringae strains were cultured in high throughput microbioreactors (48-well BioLector, m2p labs, GmbH). Subsequently, a strain with the potential for lipopeptide production was chosen to be cultured in lab scale bioreactors. As a result, most bacterial strains produced relatively high biomass, which is a key element leading to superior production of the target compounds. Moreover, 85% of strains possessed the capacity to synthesize and secrete lipopeptides in microbioreactors by feeding on a simple culture medium, and 69% of strains produced lipopeptides higher than 50 mg/L. The potential strain chosen from the above screening study exhibited about 100 mg/L lipopeptide production in lab-scale bioreactors. The substantial lipopeptide production exhibited by a significant proportion of strains in micro-size bioreactors and even greater yields in lab scale bioreactors suggests the potential of P. syringae for large-scale lipopeptide production.