Improvement of biomass and cyclic lipopeptides production in Bacillus amyloliquefaciens MEP218 by modifying carbon and nitrogen sources and ratios of the culture media

Fengycins From Bacillus amyloliquefaciens MEP218 Exhibit Antibacterial Activity by Producing Alterations on the Cell Surface of the Pathogens Xanthomonas axonopodis pv. vesicatoria and Pseudomonas aeruginosa PA01

“…This strain possesses biocontrol properties (Príncipe et al, 2007;Alvarez et al, 2012). The MEP 2 18 was grown in Lysogeny broth (LB) or in Modified Medium Optimal for Lipopeptide Production (MMOLP) (Medeot et al, 2017) for 48 h at 30 • C and 150 rev min −1 . Xav, the phytopathogenic bacterium causing the bacterial spot disease on pepper (Capsicum spp.)…”

“…Cyclic lipopeptides from MEP 2 18 were precipitated from the cell free culture supernatant following acidification with HCl (12 N) until pH = 2,0 (Vater et al, 2002;Kim et al, 2004;Medeot et al, 2017). Precipitated CLP were suspended in 100% methanol, filtered through a 0.22 µm nylon membrane, and injected onto a high-performance liquid chromatography (HPLC) (Infinity LC Grad, Agilent) column (Analytical Zorbax C18, 4.6 mm × 150 mm, Agilent).…”

“…The temperature was maintained at 37 • C. Separation was achieved by using a mixture of solvents consisting of acetonitrile (solvent A) and water acidified with 0.1% formic acid (solvent B) with a flow rate of 1 mL min −1 . For each run, 100 µl of sample was injected into the HPLC column and eluted using the conditions described in Medeot et al (2017).…”

“…The peaks with a retention time of 27.4 min, corresponding to fengycins (Medeot et al, 2017), from several HPLC runnings were collected, lyophilized and the powder was weighed and suspended in 100% methanol at final concentrations of 1 and 10 mg mL −1 . These solutions were used as stocks of fengycins.…”

“…These fengycins exhibited an increased antibacterial activity against Xanthomonas axonopodis pv. vesicatoria (Xav), the phytopathogenic bacterium causing the widespread and harmful bacterial spot disease on tomato plants (Solanum lycopersicum) in comparison with those obtained in the unmodified culture medium (Medeot et al, 2017).…”