<![CDATA[ABSTRAK Pelepah aren (Arenga pinnata Merr) digunakan oleh masyarakat sebagai obat jerawat. Penggunaan secara empiris di masyarakat pelepah aren dibakar kemudian abunya dipakai sebagai masker. Dilakukan pengujian aktivitas antimikroba ekstrak etanol, fraksi air, fraksi etil asetat dan fraksi n-heksana terhadap bakteri Propionibacterium acnes dan Staphylococcus aureus dengan metode agar perforasi. Ekstraksi dilakukan dengan metode maserasi dengan pelarut etanol. Ekstrak etanol di fraksinasi dengan pelarut air, etil asetat, dan n-heksana. Hasil ekstrak dan fraksi dipekatkan dengan “rotary evaporator†dan dikentalkan di penangas air. Konsentarsi hambat minimum (KHM) ekstrak etanol 35% dan fraksi etil asetat 7,5% memberikan diameter hambat berturut-turut (14±0,06) mm dan (14±0,04) mm terhadap bakteri Propionobacterium acnes. Konsentrasi hambat miminum (KHM) ekstrak etanol 18%, fraksi air 40%, dan fraksi etil asetat 2,5% memberikan diameter hambat berturut-turut (14,6±0,13) mm, (14±0,06) mm, dan (14±0,06) mm terhadap bakteri Staphylococcus aureus. Hasil pengujian aktivitas mikrobiologi menunjukkan bahwa fraksi etil asetat paling potensial dalam menghambat kedua bakteri uji. Kata kunci : pelepah aren (Arenga pinnata Merr), Propionibacterium acnes, Staphylococcus aureus, jerawat, difusi agar perforasi. ABSTRACT Palm frond (Arenga pinnata Merr) is used by the public as an acne medication. The use of empirically in the community burned palm frond ashes then used as a mask. Testing the antimicrobial activity of the ethanol extract, water fraction, the fraction of ethyl acetate and n-hexane fraction of the bacteria Propionibacterium acnes and Staphylococcus aureus with difussion perforation method. Extraction is done by the method of maceration with ethanol. The ethanol extract is fractionated by water solvent, ethyl acetate, and n-hexane. Results extracts and fractions concentrated by "rotary evaporator" and thickened in water bath. The minimum inhibitory concentration (MIC) of 35% ethanol extract and 7.5% ethyl acetate fraction gives a row inhibitory diameter (14 ± 0.06) mm and (14±0.04)mm to Propionobacterium acnes bacteria. Miminum inhibitory concentration (MIC) of 18% ethanol extract, 40% water fraction, and 2.5% ethyl acetate fraction gave inhibitory consecutive diameter (14.6 ± 0.13) mm, (14 ± 0.06) mm, and (14 ± 0.06) mm against Staphylococcus aureus. The test results showed that the microbiological activity of ethyl acetate fraction is the most potent in inhibiting both bacterial test. Key words  : palm frond (Arenga pinnata Merr), Propionibacterium acnes, Staphylococcus aureus, acne, diffusion perforation method.]]>
