Uji Aktivitas Antibakteri Ekstrak Bakteri Endofit dan Identifikasi Bakteri yang Diisolasi dari Kulit Jeruk Nipis (Citrus aurantifolia Swingle)

Abstract

Lime peel (Citrus aurantifolia Swingle) is a plant part widely used for treatment with various pharmacological activities. However, little is known about the study of endophytic bacteria associated with the peel of this plant. This study aimed to isolate endophytic bacteria from lime peel and evaluation its activity in inhibiting the growth of Staphylococcus aureus, Escherichia coli, and Methicilin-Resistant Staphylococcus aureus (MRSA) bacteria. Six bacterial isolates were isolated and fermented in Nutrient Broth (NB) media. The results of the fermentation were extracted using ethyl acetate as a solvent. The crude extract of each isolate was evaluated for its antibacterial activity using the Kirby-Bauer diffusion method. According to the inhibition zone measurements, it was shown that the extracts from isolate 3 and isolate 5 had a strong inhibitory diameter of >10 mm. Qualitative identification showed that the extract from isolate 3 showed positive results for alkaloids and flavonoids, while isolate 5 was positive for alkaloids, flavonoids, and polyphenols. These isolates were then identified, and it was reported that isolate 3 was Bacillus velezensis JS25R, and isolate 5 was Staphylococcus sp. This extract has been proven to have the potential as antibacterial and to be further isolated and developed by its activit