Uji Antimikrobial Ekstrak Metanol Daun Jambu Biji Daging Putih dan Jambu Biji Daging Merah (Psidium guajava L.) terhadap Beberapa Spesies Bakteri Patogen

Abstract

The study of antimicrobial methanolic extract of leaf white and red guava (Psidium guajava L.) to the growth of E. coli, S. aureus, S. dysenteriae, B. subtilis, S. marcescens was conducted in Microbiology Laboratory, Biology Department, Faculty of Mathematic and Natural Sciences, Sumatera Utara University from August to October 2008. Agar diffusion Kirby-Bauer method was used in this study. The results showed that methanolic extracts of white and red guava have different activity in inhibiting the growth of the pathogenic bacteria. The leaf methanolic extract of leaf white guava showed the highest activity in inhibiting the growth of S. dysenteriae, B. subtilis and followed by S. aureus . However, leaf white guava methanolic extract has not effect in inhibiting the growth of E. coli and S. marcescens. Whereas, the methanolic extract of leaf red guava showed the highest activity in inhibiting the growth of S. dysenteriae, B. subtilis, and S. aureus respectively. Whereas, E. coli and S. marcescens have low effect in inhibiting the growth of the bacteria. Chloramfenicol and penicilin used as comparable antibiotic in this study showed the low effect in inhibiting the growth of the bacteria.