PRODUCTION AND CHARACTERIZATIONS OF BIOSURFACTANT PRODUCED BY HALOPHILIC BACTERIA PSEUDOMONAS ALCALIPHILA

• Main Author: NANCY MAULITHA (NIM :10510012) ; Pembimbing : Dr. Rukman Hertadi, M.Si ; Dr. Deana Wahyuningr, DEBORA
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18261
• Institution: Institut Teknologi Bandung

Biosurfactant is a biological surface-active molecule (surfactant) that produced biochemically via microorganism secondary metabolism. The aim of this study is to produce and to characterize biosurfactant produced by Pseudomonas alcaliphila isolated from concentrated saline water around the mud cratter at Bledug Kuwu, Purwodadi, Central Java. Pseudomonas alcaliphila has been examined its potential to produce biosurfactants based on the positive result of haemolytic assay. The optimum conditions for biosurfactant production from these bacteria were explored by varying carbon and nitrogen sources. Palm oil, lemon grass oil, sesame oil, olive oil, corn oil, and soybean oil were used as carbon sources. Meanwhile, NH4Cl, NaNO3, KNO3 and CO(NH2)2 were used as nitrogen sources. Oil spreading test (OST) was devised to quantify biosurfactant activity, which is based on the maximum diameter of oil spreading on the biosurfactant solution. The maximum OST was obtained from the biosurfactant produced in the culture medium containing soybean oil and KNO3 as carbon and nitrogen sources, respectively, with the incubation time as long as 128 hours at the aeration rate of 150 rpm and 37 °C. At this optimum condition, the produced biosurfactant gave the longest diameter in oil spreading, which was about 3 centimeters in length. Further characterization observed that the highest activity of this biosurfactant was found when it was disolved in the solution with pH range of 6-9, containing 5% (w/v) NaCl, and incubated at room temperature (25-27 °C). The produced biosurfactant also gave positive result on CTAB test suggesting that it is belong to anionic biosurfactant groups, which was well-known as rhamnolipid. Our result, therefore, showed that locally isolated Pseudomonas alcaliphila from mud volcano Bleduk Kuwu, Purwodadi, Central Java potentially produce rhamnolipid type of biosurfactant.