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 , Salmone l la typ h i , Staphylococcus aureus , Candida albicans , and Candida tropicalis by calculating the zone of microbial growth inhibition. Among the plant extracts, T 5 that identified as Toona sinensis showed the highest microbial inhibit ion to 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 then subsequently fractionated using n-hexane, ethyl acetate, and methanol , respectively. The resulted fractions also were evaluated for antimicrobial bioassay. A ll fractions have shown activity in inhibiting the growth of the microbes at 1% concentration. However, each fraction show ed growth inhibition against certain microbe s . The n-hexane fraction show ed 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 as an antimicrobial agent . Further investigation is needed to observe the mode of anti microbial 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