Exploration of Bio-medicinal Potential of Bryophyte Endophytic Bacteria from Gedong Songo

Endophytic bacteria are known to produce diverse bioactive metabolites, often in higher concentrations than their host plants. This study aimed to isolate endophytic bacteria from geothermal bryophytes in the Gedong Songo hot spring area (Semarang Regency, Indonesia) and evaluate their antioxidant, antiglycation, anti-aggregation, antibacterial, and biosurfactant activities. From 300 colonies, 11 isolates were selected based on distinct morphological characteristics. The highest antioxidant activity was shown by L11 with 63.58% inhibition, while L2 exhibited the strongest anti-aggregation activity (71.96%). The greatest antiglycation activity was observed in L5 (38.76%). Antibacterial assays showed that L9 produced the largest inhibition zones against Escherichia coli (1.34 cm) and Staphylococcus aureus (1.40 cm). The highest biosurfactant activity was recorded in L3, with an oil spreading area of 4.79 cm² on day 14. These results indicate that geothermal bryophyte–associated endophytic bacteria are promising sources of bioactive metabolites.