#TITLE_ALTERNATIVE#

• Main Author: YULIANA (NIM : 20512058) ; Pembimbing Dr. Rukman Hertadi, Dr. Deana Wahyuningrum, CUT
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18229
• Institution: Institut Teknologi Bandung

The development of bioprocess technology have opened the way towards the production of biological surfactant (biosurfactants) that environmentally more friendly. This study focused on the production dan characterization of biosurfactant derived from halophilic bacteria Halomonas meridiana BK-AB4 dan Chromohalobacter japonicus BK-AB18. The first stage of this study was to examine the potential biosurfactant’s production by both halophilic bacteria with hemolysis assay dan to determine the type of the resulted biosurfactants using blue agar assay. Both H. meridiana BK-AB4 dan C. japonicus BK-AB18 showed high hemolytic activity with the size of the clear zone on the blood agar 3.2 cm dan 3 cm in diameters, respectively. The blue agar assay, however, apparently did not give positive results for both bacteria, suggesting that the produced biosurfactants were not belong to rhamnolipid group. The next stage was the optimization of biosurfactant’s productions by culturing both bacteria in minimal CY media varying carbon dan nitrogen sources dan with the aeration rate of 150 rpm at 37 oC for 8 days. The carbon source used in this study were olive oil, corn oil, soybean oil, palm oil, dan sunflower oil, while for the nitrogen source were urea, NaNO3, NH4Cl, NH2(SO)4 dan KNO3. The biosurfactant production from H. meridiana BK-AB4 was optimized using olive oil dan urea as carbon dan nitrogen sources, respectively, as indicated by the results <br /> <br /> <br /> <br /> <br /> iv <br /> <br /> <br /> <br /> <br /> of the oil spreading dan emulsification assays which gave the respective value of 5.2 cm dan 82%. In case for C. japonicus BK-AB18, its biosurfactant’s production was optimized using olive oil as a carbon source dan urea as nitrogen sources with oil spread test results of 4.7 cm dan emulsification of 76%. Biosurfactants produced from the optimized media were then assayed their activity in various conditions of pH, temperature, dan salinity. The optimum pH for H. meridiana BK-AB4 was in the range of 8-11, while for the C. japonicus BK-AB18 was optimized at pH range of 9-11. In search for the optimum temperature, we noted that both biosurfactants from H. meridiana BK-AB4 dan C. japonicus BK-AB18 showed maximum activities temperature range of 70-90 oC. Meanwhile, the result of salinity assay found that biosurfactants from H. meridiana BK-AB4 exhibited maximum activity in salinity range of 15-22%, whereas for C. japonicus BK-AB18 was optimized in 17-20 % of salinity. The density of biosurfactants produced by the H. meridiana-AB4 BK dan C. japonicus BK-AB18 were 52 g / L dan 44 g / L. TLC analysis gave Rf values of 0.62 dan 0.63 for H. meridiana BK-AB4 dan C. japonicus BK-AB18, respectively. Biosurfactant produced from H. meridiana BK-AB4 dan C. japonicus BK-AB18 found CMC value 250 mg/ L dan 260 mg/L, respectively. The DSC thermogram showed Tm value that similar for both bacteria melting point for Tm1 at 84,0 oC, melting point for Tm2 at 219,3 oC dan Tm3 at 448,2 oC. FTIR structural analysis for both resulted biosurfactants exhibited similar functional groups, namely N-H group at wave number of 3400-3500 cm-1, C=N group at 1600-1650 cm-1, C-N group at 1000-1200 cm-1 dan C-Cl group at 600-630 cm-1. All of above showed that both H. meridiana BK-AB4 dan C. japonicus BK-AB18 have high potential to produce biosurfactants.