Isolation and Selection of Growth Medium for Microalgae of Lake Biru Sawahlunto West Sumatra and Antibacterial Activity Test

摘要

This research was done to overcome the bacterial resistance towards antibiotics by produced new antibiotics. Some microorganisms can be used as a source of antibiotics, including microalgae. This study was conducted by using microalgae Scenedesmus dimorphus to produced a new antibiotic. The study began by looking for a suitable growth medium to obtain maximum biomass to produces antibiotics. The results showed that the suitable growth medium was Bolt Basalt Medium (BBM) with dry biomass of 0.602 g/L,whereas from grow more 632% medium was obtained 0.302 g/L and commercial fertilizer P5 was obtained 0.479 g/L. The antibacterial activity of Scenedesmus dimorphus extract was tested using the disc diffusion method (Kirby & Bauer test). The extraction process using methanol, ethyl acetate and hexane solvents was carried out by the maceration method with the help of the sonication process. Antibacterial activity testing showed the inhibition zone on methanol extract using Bacillus subtilis ATCC 6633, Salmonella thypimurium ATCC 14028, Eschericia coli ATCC 25922, Methicilin Resistent-Staphylococus aureus ATCC 25175 respectively 13 mm, 10 mm, 10 mm, 20 mm while on ethyl acetate extracts the inhibition zone size were 9 mm, 8 mm, 11 mm, 12 mm and n-hexane extracts were 8 mm, 7 mm, 8 mm and 8 mm.