Analytical methods for antioxidant screening of endophytic bacteria: A comparative review

Endophytic bacteria, living symbiotically in plant tissues, have attracted great attention due to their antioxidant potential. These microorganisms are capable of producing bioactive compounds, including enzymes and secondary metabolites, which help reduce oxidative stress in plants and can be cultured in artificial media, opening up broad prospects for future applications. This article provides an overview of the antioxidant potential of plant endophytic bacteria, focusing on spectroscopic analytical techniques: 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) free radical neutralization, 2,2-diphenyl-1-picrylhydrazyl free radical neutralization (DPPH), ferric reducing-antioxidant power (FRAP) and total antioxidant capacity (TAC). These methods collectively highlight the strong antioxidant capacity of endophytic bacteria and underscore their role as a promising source of natural antioxidants for future biotechnological applications.