Antimicrobial Activity of Ten Extractives from Toba, North Sumatra and Mt. Merapi National Park Regions, Indonesia

Investigating beneficial chemical compounds of plant extracts is one of the ways to prevent biodiversity loss. This study evaluated the antimicrobial activity of indigenous plant extracts from Toba, North Sumatra, and Mt. Merapi National Park regions against Escherichia coli, Bacillus subtilis, Salmonella typhi, Staphylococcus aureus, Candida albicans, and Candida tropicalis by calculating the zone of microbial growth inhibition. Among the plant extracts, T5 that identified asToona sinensisshowed the highestmicrobial inhibitionto the growth of C. albicans, B. subtilis, S. typhi, and E. coli with the diameter growth of approximately 2.00, 1.80, 1.33, and 1.33 cm, respectively. Based on those results, T. sinensis was thensubsequently fractionated using n-hexane, ethyl acetate, and methanol, respectively.The resulted fractions also were evaluated for antimicrobial bioassay. All fractions have shown activity in inhibiting the growth of the microbes at 1% concentration. However, each fraction showedgrowth inhibition against certain microbes. The n-hexane fraction showed the greatest inhibitory activity for E. coli and S. typhi; ethyl acetate fraction for B. subtilis and C. albicans; and methanol fraction for E. coli and S. typhi. The results revealed that T. sinensis plant extract has great potential asan antimicrobial agent. Further investigation is needed to observe the mode of antimicrobial action of fractionated crude extracts of T. Sinensis. The exploring potency of Indonesian biodiversity opened up a new way for the utilization of plants for economic development and conservation. Keywords: antimicrobial plants, indigenous knowledge, Toba-North Sumatra, Mt. Merapi