Background: Bacillus velezensis and other Bacillus species are known for the production of bioactive secondary metabolites that are active against plant pathogenic fungi. In view of this, a study was undertaken to investigate the antifungal potential of B. velezensis AR1 culture supernatant.
Result: The butanol extract concentrate of B. velezensis AR1 was separated into different fractions by column chromatography. A fraction eluted by 9:1 chloroform: methanol caused 25.8-70.2% and 25.2-56.3% growth inhibition of Monilinia fructicola and Colletotricum goeosporioides, respectively. This fraction was subjected to solid-phase extraction using a Strata SI-1 column and further purified by prep-TLC to obtain a pure metabolite showing a single peak on high performance liquid chromatography. On the basis of the nuclear magnetic resonance (NMR 1 H, 13 C, HH COSY, HSQC and HMBC) analysis, the metabolite was identified as 5-N-tyrosinylornithine. The compound exhibited antifungal activity against two plant pathogenic fungi.
Conclusion: 5-N-tyrosinylornithine, the secondary metabolite isolated from the culture supernatant of B. velezensis AR1 exhibited significant antifungal activity against two plant pathogenic fungi.
Keywords: Bacillus velezensis; antifungal activity; crop protection; fungicidal activity.
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