Isolation and characterization of Bacillus endophytic strains producers for non ribosomal lipopeptides NRLPs from tomato
Tomato (Solanum lycopersicum) are considered one of the most important vegetable crops and infected by numbers of different diseases. Studying the use of biological alternatives, instead of chemical substances against plant diseases became necessary for the treatment by beneficial microorganisms endophytes, which can excrete natural products benefits to plant in reducing disease severity, promoting growth and inducing plant defence mechanisms. In this work, three endophytes strains were isolated from tomato stems and their 16srDNA have been found to belong to Bacillus species. The first strain was named BMG100, the second BMG101 and the third BMG102. Two Bacillus strains BMG100 and BMG101 have been found to harbour synthetases genes from three lipopeptides families; surfactin, plipastatin, and iturin (mycosubtilin) which can be detected by degenerated primers designed to detect the presence of synthetases genes encoding lipopeptides. The lipopeptides production was proved by their quantification using High Performance Liquid Chromatography (HPLC), whereas BMG100 produced 105, 178 and 293 mg/L of plipastatin, mycosubtilin and surfactin, respectively, BMG101 produced 385 mg/L of surfactin and 236 mg/L of mycosubtilin, while BMG102 showed no lipopeptides production. Keywords: Tomato; Endophytic bacteria; Lipopeptides; Bacillus species