Isolating Miliusa velutina endophytic bacteria to generate antioxidants and optimizing culture conditions for antioxidant production

Miliusa velutina (MV) antioxidants are being used for food or medical purposes, However, the use of the plant is limited since some Miliusa genus are endangered or critically endangered species. This study aims to find the MV endophytic bacteria that can produce the antioxidants (total phenol content (TPC), total flavonoid content (TFC), total antioxidant capacity (TAC), reducing power (RP); and ferric reducing antioxidative power (FRAP)) and their optimum fermentation condition by utilizing morphology, SEM, 16S rRNA, and CCD model. Results found that 44 endophytic bacterial strains isolated from various parts of the plant showed promising antioxidative activities, with the highest produced by Pantoea sp. MV -R3. The model indicated that 15.41 g/L of glucose in pH 7.72 at 29.19 degrees C for 46.54 h was the optimal fermentation condition. The maximal activities reached 89.1 % to 129.0 % compared with the predictions. The activities of TPC, TFC, TAC, RP, and FRAP were 41.54 +/- 7.69, 33.18 +/- 4.55, 207.36 +/- 30.89, 119.55 +/- 14.34, and 57.02 +/- 9.15 mg per mL, respectively. Hence, the MV endophyte and its optimum fermentation condition were successfully identified. (c) 2024 SAAB. Published by Elsevier B.V. All rights reserved.