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EVALUATION OF THE SURFACE TENSION OF RHAMNOLIPID AT DIFFERENT
TEMPERATURE AND ITS OIL DISPLACEMENT PROPERTIES
LAI KUN TING
SUPERVISOR: ASSOC. PROF DR. KESAVEN A/L BHUBALAN
BACHELOR OF SCIENCE (MARINE BIOLOGY)
SCHOOL OF MARINE AND ENVIRONMENTAL SCIENCES
UNIVERSITI MALAYSIA TERENGGANU
Rhamnolipid (RL) is biosurfactant that can reduce the surface tension of liquid. In this
study, a marine bacterium, Pseudomonas aeruginosa UMTKB-5 was employed to
produce RL. Quantification of RL produced was done using orcinol assay and surface
tension measurement were carried out with a tension meter. The purified RL at
concentrations of 0.10, 0.15, 0.30 and 0.45 mg/mL were applied in oil displacement
test on palm olein (PO) and crude palm oil (CPO) at room temperature, 60 0 C and 80 0 C.
Results showed the yield of RL produced is 96 mg/L with cell biomass of 109 mg/L
and the surface tension readings were in the range of 26.000 mN/m and 29.000
mN/m. The largest diameter of 7.8 cm clear zone was achieved with 0.45 mg/mL of
RL at 80°C on PO. From these results, it is concluded that RL produced by this marine
bacteria has high surface activity even at elevated temperature.
1818 | UMT UNDERGRADUATE RESEARCH DAY 2018