Biochemical and antimicrobial properties of bacterial endophytes isolated from yarrow (Achillea millefolium) and tragacanth (Astragalus gossypinus) in Fars geographical regions

Yarrow (Achillea millefolium) and tragacanth (Astragalus gossypinus) are medicinal plants in the Middle East which have been used for medical purposes. The presence of endophytic bacteria in the medicinal plants has been recently focused by many researchers. Endophytes are bacteria and fungi in the inner parts of the plant tissues which in addition to their benefits for the plants, contain effective bioactive compounds. In this research, endophytic bacteria were isolated from yarrow and tragacanth. Their antifungal and antibacterial activities against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATTC 35218), Salmonella Typhimurium(ATCC 14028), Listeria monocytogenes (PTCC 1163) and Aspergillus niger (PTCC 5154) were assessed using disk diffusion method. Bacteria having antimicrobial activity were further identified by 16S rDNA, biochemical characteristics and enzyme activities. The bacteria isolated from yarrow and tragacanth were found as Bacillus safensis and Bacillus pumilus, respectively. These isolates showed inhibitory effects against the tested fungi. B. safensis could ferment D- glucose, sucrose, mannitol, and lactose. The activities of oxidase, catalase, gelatinase, protease, and amylase enzymes were also investigated. B. pumilus could only ferment D-glucose and represented the activities of oxidase, catalase, and amylase.