The antimicrobial, antioxidant, and anti-inflammatory properties of extract from Bacillus subtilis RGT2 was examined to assess the prospective of bacteria as a source of natural products with therapeutic potential. These properties were analyzed by performing a set of standard assays. The extract obtained with ethyl acetate showed variety of components: flavonoids, polyphenols, alkaloids, steroids, glycosides, and tannins, as they yielded promising results in all completed assays. The antioxidant activity of Bacillus subtilis RGT2 extract was evaluated
using several methods (DPPH (1,1-diphenyl-2-picrylhydrazyl, EC₅₀=57.38±2.30 µg/mL); ABTS^•+ (2,2-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid, EC₅₀=57.01±0.50 µg/mL); FRAP (ferric reducing antioxidant power, EC₅₀=41.41±0.31 µg/mL), TAC (total antioxidant capacity, EC₅₀=94.80±3.16 µg/mL), RP (reducing power, EC₅₀=32.00±0.37 µg/mL), and the results showed good antiradical effects. Moreover, the antimicrobial evaluation
showed a potent antibacterial activity against Staphylococcus aureus (MIC=160 µg/mL; MBC=1280 µg/mL. The extract from Bacillus subtilis RGT2 demonstrated anti-inflammatory activity in a dose dependent pattern with a half maximal inhibitory concentration (IC₅₀) value of 73.74±1.77 µg/mL. Results demonstrated that _{Bacillus subtilis} RGT2 extract can represent an important natural source with high antimicrobial, antioxidant, and anti-inflammatory potential effects.
Keywords: Bacillus subtilis RGT2, antibacterial, antioxidant, anti-inflammatory, Staphylococcus aureus