| dc.description.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. | en_US |
