A new source of anti-hyperglycemic agent: endophyte bacteria isolated from stems of sea ferns (Acrostichum aureum l.) on Rupat Island, Riau Province, Indonesia

Endophytic bacteria are microorganisms that are symbiotic with plants without causing adverse effects to the plants. Generally, the compounds produced by the host plant align with those produced by the endophytic bacteria. Secondary metabolites of endophytic bacteria are reported as antibacterial, anticancer, enzyme production, and pharmaceutical agents. This study aims to isolated, screening and test the activity of secondary metabolites of endophytic bacteria from the stems of sea fern (Acrostichum aureum L.), producing antioxidants and α-amylase inhibitors. This study obtained 20 isolates of endophytic bacteria isolated using a NA medium. Three isolates of endophytic bacteria were selected from the screening results using MRSA and MRSA media with the addition of CaCO3, namely isolates BRS 2.3, BRS 5.2, and BRF 5.1. Three isolates were tested for antioxidants using dry extract with ethyl acetate solvent 1:1. Percent inhibition of each isolate was 51.619%, 14.794%, and 30.495%. The α-amylase inhibitor activity of isolate BRF 5.1 was 8.05% on 1% starch substrate and 23.76% on 2% starch. This preliminary investigation will be useful in the identification and use of functional products containing anti-diabetic benefits.