Karakterisasi Biosurfaktan dari Bakteri Bacillus cereus

Abstract

Many studies have been carried out on the ability of bacteria to break down various hydrocarbon compounds including pesticides. Further research on the enzymes that code for these degrading genes have also been carried out, but the characterization of biosurfactants produced by bacteria that decompose PAH compounds has not been studied much. This research aims to obtain the characteristics of the biosurfactant secreted by Bacillus cereus which includes biosurfactant activity such as the drop collapse test and emulsification index, emulsion stability, and the composition of the biosurfactant which was analyzed using Liquid Chromatography Mass Spectrometry (LC-MS). Once the characteristics of biosurfactant was known, it could facilitate further application of this compound. The results of research on biosurfactant activity showed positive results in the drop collapse test and the highest emulsification index value was obtained 57.64%. The best environmental factors to achieve the highest emulsion index value were: temperature of 30oC, pH of 12, and 0% of salt concentration. Characterization of the biosurfactant revealed that the biosurfactant consisted of 16 components which was dominated by the amino acid alanine with a retention time of 14.66. These compounds have similarity to the amino acids content in other lipopeptide biosurfactants, such as surfactin. The amino acid alanine is thought to play an important role in biosurfactant activity, namely emulsification. Apart from the alanine compound, there are 5 other amino acid compounds found in this biosurfactant. They are, leucine, ornithine, threonine, tyrosine and isoleucine. These compounds can generally be found in lipopeptide biosurfactants.