In a previous study, Bacillus amyloliquefaciens strain CEIZ-11 has been isolated from a compost extract and
showed a broad spectrum of antifungal activity against various plant pathogenic fungi. The potential of
Bacillus genus to antagonize phytopathogens is due to the production of some metabolites, mainly cyclic
lipopeptides. In the present study, polymerase chain reaction was used to screen CEIZ-11 for genes
involved in biosynthesis of lipopeptides. Amplicons of expected sizes were detected as ituC and ituD, srfp
and fenD involved in iturin, surfactin and fengycin synthesis respectively. Lipopeptides, extracted by acid
precipitation of culture filtrate, exhibited strong antifungal activity with MIC values ranging from 9.8 to
156 lg/mL and an excellent stability to high temperature (20 min at 121 C) and a large range of pH, 2–
11. The crude lipopeptides was subjected to reverse phase high-performance liquid chromatography
(HPLC). Five major fractions were detected. Each fraction was further purified by revered phase C18 analytical
column. Identification of individual fractions was done by liquid chromatography coupled with
mass spectroscopy. Three families of lipopeptides were detected including three homologues of iturin
A (A2, A3-5 and A6), one fengycin A having fatty acyl chain length of C16 and one surfactin (C12). To evaluate
the potential application of B. amyloliquefaciens strain CEIZ-11 to control damping-off, tomato was
used as model. The pot experiments results showed that CEIZ-11 could be a promising agent in biocontrol
of damping-off.