FRACTIONATION AND ANTIBACTERIAL ACTIVITY TEST OF SECONDARY METABOLITES FROM MARINE BACTERIA BACILLUS VELEZENSIS

• Main Author: Christian Tandiary, Jeremy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/82617
• Institution: Institut Teknologi Bandung

Increasing bacterial resistance is a serious concern for many countries, including Indonesia. The use of early antibiotics is becoming increasingly ineffective in suppressing bacteria, prompting many health experts to search for new candidate antibiotic compounds. The search for new candidate compounds is widely conducted in various ecosystems, one of which is the sea because the diversity of living organisms and extreme environmental conditions allow the isolation of new compounds that are active antimicrobials. Bacillus velezensis is one of the bacteria from the collection of the Microbiology Laboratory of the School of Pharmacy ITB and is known to have antimicrobial activity against Gram-negative bacteria. This study was conducted to determine the subfraction responsible for the antibacterial activity against Escherichia coli, Salmonella typhi, and Pseudomonas aeruginosa. The research included bacterial rejuvenation, bacterial identification, bacterial fermentation, extraction of secondary metabolites, fractionation of secondary metabolites, subfractionation of secondary metabolites, and testing of antibacterial activity by disk diffusion and microdilution methods to determine the value of minimum inhibitory concentration (MIC), followed by drop test to determine the value of minimum bactericidal concentration (MBC). The results showed that biomass extract, subfraction 6, and subfraction 7 each showed antibacterial activity at a concentration of 1024 ?g/mL against Escherichia coli. Other results showed that subfraction 5 showed antibacterial activity at a concentration of 1024 ?g/mL against Salmonella typhi, but no extract, fraction, or subfraction showed antibacterial activity at all concentration series tested against Pseudomonas aeruginosa. All extracts, fractions, and subfractions that provided antibacterial activity were weak and bacteriostatic.