66597

IDENTIFICATION OF BIOACTIVE SUBSTANCES PRODUCED BY BACILLUS SUBTILLIS CNPMS 22

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The interest in biological control programs grows substantially worldwide due to food and enviroment contamination by pesticides. Bacillus subtilis stands out as one of the most widely used bacteria due to its potential at bioactive substances production. The present research had as objective the identification of secondary metabolites produced by B. subtilis CNPMS 22. Initially, the pre-inoculum was prepared with 150 mL of liquid LB solution (10 g/L tryptone, 5 g/L yeast extract and 10 g/L NaCl), where a colony isolated from the culture was inoculated and incubated at 28 ºC and 250 rpm, for 18 h. The fermentation was carried out in a 2L erlenmeyer, containing 1L of LB solution with glucose (20 g/L glucose, 10 g/L tryptone, 5g/L yeast extract and 10 g/L NaCl, pH = 7); 10 mL of the pre-inoculum was inoculated and incubated at 28 ºC and 250 rpm for 72 h. After this period, the biomass was removed by centrifugation (2671 g/15 min). The extraction of the compounds from the fermented broth was peformed by acid precipitation, adding HCI 6M to reduce the pH to 2, and subsequently stored in the refrigerator for 24 h. The precipitate was collected by centrifugation (3488 g/30 min). The sediment was dissolved in methanol and then concentrated in an evaporator. The crude concentrated extract was dried by lyophilization. These compounds' identification was performed by UPLC-ESI-QTOF-MS/MS, which revealed the presence of the three main classes of lipopeptides and their counterparts (iturin, fengycin and surfactin). The identified compounds have industrial applications already reported in the literature, however finding a lineage as the CNPMS 22 capable of producing the three main lipopeptide families simultaneously is of great importance for industrial prospection.