ISOLATION OF MICROBE FROM SOIL AND EVALUATION OF ANTIBACTERIAL ACTIVITY OF THE FERMENTATION PRODUCT OF THE CHOSEN ISOLATE

• Main Author: Azhari, Muhammad
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/46921
• Institution: Institut Teknologi Bandung

Infection occupied the third position causing mortality worldwide, following stroke and heart failure. In Indonesia and some other developing countries, infection diseases is found to be the most dominant health problem in several region. Hence, the search for new antibacterial substances continues until today. Indonesia has a flourishing soil that provide a good habitat for most fauna, flora, as well as microorganism. Actinomycetes is a group of bacteria that has an important role in anticancer and antibiotic industry which often found in soil. This study aims to isolate and characterize microbe from soil of Galunggung Mountain, Papandayan Mountain, and tea field in Pangalengan, as well as to evaluate antibacterial activity of its fermentation product against both susceptible and resistant antibiotic pathogenic bacteria. This study includes isolation of antibiotic producing microbe, physiological, biochemical, and molecular identification and characterization of isolate microorganism, medium modification and optimization of antibiotic production, fermentation and characterization of secondary metabolites using bioautography method. The results of characterization by macroscopic, microscopic, biochemical, and molecular methods showed that the isolate is found to be Streptomyces sp. which further named as Streptomyces sp. A1. Streptomyces sp. A1 is fermented using 14 different medium composistion and the highest activity is showed by medium M11 containing dextrin, beef extract, yeast extract, peptone, dextrose, and CaCl2. Hence, medium M11 will be used for the next step. The fermentation product is extracted by liquid-liquid extraction method using ethyl acetate, chloroform, and n-butanol in pH 4,5; 7, and 9. Ethyl acetate extract has the highest antibacterial activity against Salmonella typhi and Methicillin-susceptible Coagulase Negative Staphylococci (MSCNS) with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) 62,5 µg/mL. The extract also showed antibacterial activity against Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococci (VRE), Propionibacterium acne, Escherichia coli, Vibrio cholerae, Neisseria meningitidis, dan Escherichia coli O157:H7 with MIC 125, 62,5; 62,5; 250, 125, 250, dan 250 µg/mL, respectively, and MBC 250, 125, 125, 250, 250, 500, dan 500 µg/mL, respectively. The results of bioautography using stationary phase silica gel GF254 and eluent ethyl acetate: methanol (9:1) showed that there are six spots detected using UV light ?254 nm and H2SO4 10% in methanol with Rf 0; 0,23; 0,38; 0,65; 0,84; 0,89 and there is one spot detected using UV light ?366 nm with Rf 0,89. Spot with Rf 0,89 is found to have the broadest antibacterial activities that can inhibit all test bacteria including MRSA, VRE, MSCNS, P. acne, E. coli, S. typhi, V. cholerae, N. meningitidis, dan E. coli O157:H7.