In vitro antibacterial study and spectral analysis of brown seaweed Sargassum crassifolium extract from Karimunjawa Islands, Jepara. Issue 1 (July 2020) - Ari Setyati, Wilis
Abstract: Staphylococcus aureus and Pseudomonas aeruginosa are opportunistic pathogenic bacteria that are the main causes of nosocomial infections. These bacteria can infect almost every tissue of the body and there were 15% cases of infection in hospitals. Urinary tract infections, even sepsis, where the death rate reaches 50%. Inappropriate use of antibiotics raises resistance. About 10% of bacterial isolates are generally expressed as S. aureus and P. aeruginosa Multidrug Resistant (MDR). Sargassum brown seaweed has many potential antimicrobial compounds. This research aims to screen the antibacterial active compounds of Sargassum crassifolium seaweed against S. aureus and P. aeruginosa MDR bacteria. S. crassifolium collected from waters of Karimunjawa Islands, Jepara. The research was conducted by laboratory experimental methods. Sample was extracted with diethyl ether, methanol, ethanol and chloroform. The MIC value is done by measuring the diameter of the inhibitory zone in the antibacterial activity test of the agar diffusion method. Furthermore, extracts at MIC concentrations were tested for the antibacterial activity of the diluted method by measuring bacterial OD by spectrophotometric methods. The extract with the best antibacterial activity was performed spectral analysis by GC-MS method. The results showed that the different extracts had different MIC values (p <0.05). Extracts with high antibacterial activity are extracts from diethyl ether solvent. The extract has a MICP value of P. aeruginosa 12.7 mg/ml and S. aureus 8.4 mg/ml. P. aeruginosa has exponential growth at 12 hours and death at 44 hours. While exponential S. aureus was at 16 hours and death at 36 hours. Spectral analysis of S. crassifolium extract of diethyl ether solvent showed the composition of the presence of eicosane compounds (16.22% ), dotriacontane (11.27%), nanocosane (11.09%), dicosane (9.85%), 10.13-octadeadienoic acid (9.52%). 2-butyloctanol (6.33%), pentatriacontane (5.4%), tritriacontane (5.07%), tricosane (1.6%)