Identification of Antifungal Intracellular Proteins of Endophytic Bacillus pumilus by LC–MS/MS Analysis

Endophytes are bacteria and fungi in the inner parts of the plant tissue which other than their benefits for the plants, they contain effective intracellular and extracellular bioactive compounds.The aim of this study was to investigate the antifungal activity of the intracellular content of endophytic bacteria isolated from some medicinal plants. Endophytic bacteria were isolated from 12 medicinal plants and their antifungal activities of intracellular content was observed against Aspergillus flavus , Aspergillus fumigatus , Penicillium citrinum , Fusarium oxysporum and Rhizopus stolonifer by disk diffusion method. The bacteria having intracellular antifungal activity against all five fungi were detected by 16S rRNA. LC–MS/MS analysis was perfomed to identify the probable proteins responsible for the antifungal action. The intracellular content of 12 endophytic bacteria had antifungal activity. Six of the bacterial intracellular contents' showed antifungal activity towards all five fungi. PCR analysis identified all 6 strains as Bacillus pumilus . LC–MS/MS analysis revealed the precence of cysteine rich proteins along with glyceraldehyde-3-phosphate dehydrogenase, proteinase inhibitors and alcohol dehydrogenase which may be responsible for the intracellular antifungal activities.