Perbandingan Kekuatan Antibakteri Minyak Atsiri dari Tiga Varietas Jahe (Zingiber officinale Rosc) Terhadap Baccillus subtilis dan Pseudomonas aeruginosa - Elizabeth Betty Elok Kristiani; Emma Sharon Admatha Kaya; Sri Kasmiyati (Departemen Biologi Universitas Diponegoro, 2026)
Jahe (Zingiber officinale) merupakan tanaman rempah yang banyak tumbuh di Indonesia dan diketahui memiliki potensi sebagai agen antibakteri. Penelitian ini bertujuan untuk membandingkan aktivitas antibakteri minyak atsiri dari tiga varietas jahe yaitu jahe gajah (Z. officinale var. Roscoe), jahe merah (Z. officinale var Rubrum), dan jahe emprit (Z. officinale var Amarum) terhadap bakteri Bacillus subtilis dan Pseudomonas aeruginosa. Ekstraksi minyak atsiri menggunakan teknik sohkletasi dengan pelarut etanol. Uji aktivitas antibakteri menggunakan metode difusi cakram. Rendemen minyak atsiri tertinggi Z. officinale var Rubrum 23,45 ± 3,32 %, diikuti Z. officinale var Amarum 19,90 ± 2,17 % dan terendah Z. officinale var. Roscoe 15,70 ± 2,42 %. Pada semua konsentrasi uji, kemampuan minyak atsiri jahe dalam menghambat pertumbuhan Baccillus subtilis lebih kecil secara signifikan dibandingkan tetrasiklin dalam tetapi lebih besar pada P. aeruginosa. Hasil uji antibakteri minyak atsiri semua tiga varietas jahe pada konsentrasi 62,6 – 1000 µg/mL terbukti menghambat pertumbuhan kedua bakteru uji dalam kategori kuat yaitu diamter daya hambat > 20 mm. Kekuatan aktivitas antibakteri minyak atsiti terhadap B. Subtilis lebih rendah dari antibiotika standar tetrasiklin, sedangkan terhadap P. aeruginosa lebih kuat. Minyak atsiri ketiga variets berpotensi untuk dijadikan sebagai agen antibakteri terhadap strain gram negatif dan gram positif. Ginger (Zingiber officinale) is a spice plant that grows widely in Indonesia and is known to have potential as an antibacterial agent. This study aims to compare the antibacterial activity of essential oils from three varieties of ginger, namely elephant ginger (Z. officinale var. Roscoe), red ginger (Z. officinale var Rubrum), and emprit ginger (Z. officinale var Amarum) against Bacillus subtilis and Pseudomonas aeruginosa bacteria. Essential oil extraction was performed using the Soxhlet extraction technique with ethanol as the solvent. Antibacterial activity was tested using the disk diffusion method. The highest essential oil yield was obtained from Z. officinale var. Rubrum at 23.45 ± 3.32%, followed by Z. officinale var. Amarum at 19.90 ± 2.17% and the lowest from Z. officinale var. Roscoe at 15.70 ± 2.42%. At all test concentrations, the ability of ginger essential oil to inhibit the growth of Bacillus subtilis was significantly lower than that of tetracycline, but higher than that of P. aeruginosa. The antibacterial test results of essential oils from all three ginger varieties at concentrations of 62.6–1000 µg/mL proved to inhibit the growth of both test bacteria in the strong category, namely with an inhibition diameter > 20 mm. The strength of the antibacterial activity of essential oils against B. subtilis was lower than the standard antibiotic tetracycline, while against P. aeruginosa it was stronger. The essential oils of the three varieties have the potential to be used as antibacterial agents against gram-negative and gram-positive strains.