Characterization of medicinal plant-associated biocontrol (SSL2) by liquid chromatography-mass spectrometry and evaluation of compounds by and methods.

This study explores the antimicrobial properties of bioactive secondary metabolites extracted from the medicinal plant ()-associated strain SSL2. The secondary metabolites were extracted from (SSL2) using ethyl acetate, acetone, butanol, chloroform and methanol solvents. The crude extract was tested against two wilt causing pathogens: and . The results revealed that the ethyl acetate extract has maximum inhibition against both the pathogens tested in this study. Furthermore, liquid chromatography-mass spectrometry (LC-MS) analysis of ethyl acetate extract identified 80 different compounds based on mass-to-charge ratio, database difference, resolution of mass spectrum and so on. Among the 80 compounds, citrulline (/ = 158.0917), chloramphenicol (/ = 195.075) and carnitine (/ 162.11) were further selected based on ratio for and analyses. The i analysis revealed that citrulline, chloramphenicol and carnitine inhibited the virulent genes () and (). Further, under condition, citrulline and chloramphenicol were found to inhibit the growth of and . On the basis of the biocontrol activity of (SSL2) in and conditions, the bacteria could be used as a biocontrol agent against both bacterial and fungal wilt-causing pathogens. However, this needs to be tested in pot studies or field conditions before being used as biocontrol agents.Communicated by Ramaswamy H. Sarma.