Multiple response optimization of Bacillus subtilis EA-CB0015 culture and identification of antifungal metabolites

The low yields of biomass and antimicrobial metabolites obtained in fermentation processes are limiting factors for implementing biological control agents in the field -- In this context, optimization of the culture medium for the biological control agent Bacillus subtilis EA-CB0015 was conducted in submerged culture to maximize the biomass production and antifungal activity -- Additionally, the active metabolites against the phytopathogen Mycosphaerella fijiensis produced under optimized conditions were identified -- Carbon and nitrogen constituents of the culture medium were optimized using a 22 factorial design with central point followed by a multiple response optimization coupled to the desirability function approach -- The optimized medium (33.4 g/L of glucose and 32.5 g/L of yeast extract), showed significant increases in both, cell density by 3.6 folds (13.271.0 g/L) and antifungal activity by 1.2 folds (77.770.3% inhibition) -- To gain insight into the type of active compounds, they were purified and identified by mass spectrometry (MS) -- The MS analysis revealed the presence of three families of lipopeptides: surfactin, fengycin and iturin -- The high antifungal activity was associated with the novel fengycin C and with iturin -- A which were partially growth-associated with a maximum concentration of 781.4 and 355.4 mg/L at 36 h of growth, respectively -- These results indicate the potential of B. subtilis EA-CB0015 to produce high concentrations of biomass and lipopeptides that can be exploited for biotechnological application

• Autores: Ordúz, Sergio; Mosquera, Sandra; González Jaramillo, Lina María; Villegas Escobar, Valeska
• Fecha de publicación: 2014
• Institución: Universidad EAFIT
• Repositorio: Repositorio EAFIT
• Idioma: eng
• OAI Identifier: oai:repository.eafit.edu.co:10784/7254
• Acceso en línea: http://hdl.handle.net/10784/7254
• Palabra clave: BACILLUS SUBTILIS; METABOLITOS FUNGOSOS; BIOMASA; FERMENTACIÓN; AGENTES ANTIFUNGOSOS; CONTROL BIOLÓGICO; AGENTES BIOLÓGICOS PARA EL CONTROL DE PLAGAS; Fungal metabolites; Biomass; Bacillus subtilis; Fermentation; Antifungal agents; Biological control; Fungi as biological pest control agents; Lipopéptidos; Espectometría; Surfactinas; Bacterias como agentes biológicos
• License: Acceso restringido