Production and Characterization of Biosurfactant from Halomonas elongata BK AG-18

• Main Author: Anisa Natalia R, Deasy
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/37900
• Institution: Institut Teknologi Bandung

Increasing need for surfactant have led to a negative impact to environment due to the accumulation of surfactant waste have become a serious pollutant in water. The surfactant waste is a persistence type of pollutant because it cannot naturally be degraded. One alternative solutionto solve this problem is by using biodegradable surfactant or known as biosurfactant. Some microorganisms have been identified able to produce biosurfactants as their secondary metabolites. In the present work, halophilic bacteria Halomonas elongata BK AG-18 was evaluated its potential in producing biosurfactant. Its potential was initially identified from the positive result of the haemolysis test as revealed by the appearance of clear zone on a blood agar arround the droplet of the free cell supernatant. Biosurfactant production by Halomonas elongata BK AG-18 was carried out by growing it in MSM medium containing 2% olive oil and 0.06% KNO3 as carbon and nitrogen sources, respectively. After 30 hours of production, the resulted biosurfactant was measured its activity in terms of oil spreading capability and emulsification index. It was found that the biosurfactant was able to spread the oil up to 2.33 cm in diameter and 42.5% emulsification index. Further characterization found that the highest activity of biosurfactant was occured at 20 oC, pH-12, and in the presence of 5% NaCl. In terms of a critical micelle concentration (CMC), the biosurfactant exhibited the value of CMC at about 46.85 mg/L. In this measurement, water surface tension was decrease more than 10 mNm-1 indicating that the resulted biosurfactant has high potential to be used as the alternative synthetice surfactant. Qualitative anaysis using blue agar plate containing cetyltrimethylammonium bromide (CTAB) gave positive result as revealed by the appearance of blue color on the biosurfactant droplet on the test medium. It is indicating that the biosurfactant is categorized as rhamnolipid and the result of this test was verified with FTIR spectrum showing all relevant functional groups of rhamnolipid. All of above, thus, showed that Halomonas elongata BK AG-18 is potential source for biosurfactant production.