Optimization of Biosurfactant Condition by Bacillus sp. ALP D1 Using RSM. Hanisa Damayana (a,b), Nurhasanah (a,b)
1. Department Chemistry, Faculty Mathematics and Natural Science, University of Lampung, Jl. Soemantri Brojonegoro No. 01, Bandar Lampung, 35154, Indonesia.
2. Research Group Biochemistry , Department Chemistry, Faculty Mathematics and Natural Science, University of Lampung, Jl. Soemantri Brojonegoro No. 01, Bandar Lampung, 35154, Indonesia.
Abstract
Biosurfactants are amphiphilic compounds that act as surface active agents because it consist of two parts, hydrophilic groups and hydrophobic side. Both parts make them able to work between liquids with different polarities such as water and oil which allow them to reduce the surface tension. The nature of these biosurfactants makes them widely applied in various fields such as agriculture, industries, detergent, pharmaceutical, cosmetics, bioremediation, and others. This study aims to find the optimum condition of biosurfactant from Bacillus sp. ALP D1 used Response Surface Method Central Composite Design (RSM-CCD). The methods used rejuvenation of bacterial culture, optimization of biosurfactant carbon source (POME) concentration by 3%, 4%, 5% and production time (12 h until 120 h in the range every 12 h) at the same time that it do research directly, while nitrogen source (NaNO3) concentration by 1%, 2%, 3%, pH (6, 7, 8), salinity by (3%, 5%, 7%), it was carried out using RSM design, and the last produce biosurfactants. Determination of biosurfactant activity is done by measuring emulsification activity. The results of this study are RSM design proposed 14 experimental designs that can be undertaken to find the optimum condition of biosurfactant. The result of CCD-RSM Design is polynomial equation: Y1 = 48.6 + 3.35125 X1+ 0.13625 X2 + 2.55125 X3 - 2.98375X1X2 + 1.54625 X1X3 - 2.18375 X2X3 + 7.82125 X21. The optimum condition of biosurfactant from Bacillus sp. is seen by the value of emulsification activity obtained after the experiment design. The highest emulsification activity (IE24) was obtained 69.44% at 3% POME, 72 h, 3% NaNO3 conditions, 6 pH, and 7% of salinity levels, which indicates the optimal condition of the biosurfactant bacteria Bacillus sp. ALP D1.
Keywords: Biosurfactant, Bacillus sp., RSM-CCD, Parameter optimization, Emulsification index
