Biotechnological applications of the medicinal plant Pseudobrickellia brasiliensis and its isolated endophytic bacteria

Abstract

Aim: This study aimed to isolate Pseudobrickellia brasiliensis endophytic bacteria and evaluate the production of hydrolytic enzymes and antibiotics by these bacterial strains. The study also measured the antibacterial activity of P. brasiliensis. Methods and Results: Thirteen endophytic bacteria strains were isolated from stem and leaf fragments of P. brasiliensis. Extracellular enzyme production by the isolated endophytic bacteria was evaluated in an agar plate-based assay. The highest protease production was achieved by Bacillus subtilis P4 in alkaline medium. Antimicrobial activity of endophytic bacteria and P. brasiliensis extracts was investigated using microbroth dilution. An MIC value of 1000 μg ml−1 against Pseudomonas aeruginosa was found for B. subtilis P3, B. subtilis P5, Pseudomonas sp. P8 and Pseudomonas sp. P12. Leaf extract of P. brasiliensis showed the highest antibacterial activity against P. aeruginosa, with an MIC value of 0·781 mg ml−1. Conclusions: Pseudobrickellia brasiliensis is a source of bacterial endophytes, which can produce antibacterial compounds and enzymes. This work also demonstrated the antibacterial potential of P. brasiliensis. Significance and Impact of the Study: This is the first study that revealed the antibacterial activity of P. brasiliensis and bioactive metabolite production by P. brasiliensis endophytic bacteria.