EFEKTIVITAS BIOSURFAKTAN Pseudomonas putida T1(8) DALAM BIOREMEDIASI TANAH TERCEMAR MINYAK MENTAH

Crude oil contaminated soil was a serious problem. Bioremediation method was a viable alternative method to remedy oil contaminated soil. A possible way to increase bioremediation rate was the application of biosurfactant. Pseudomonas putida T1(8) was the native isolate which can produce extracellular biosurfactant. The aims of this research was to know the characteristic of crude biosurfactant Pseudomonas putida TI-8 product and its effectiveness when added in bioremediation test. The biosurfactant characteristics can be known by CMC value, emulsion activity in solar and kerosene and its stability at pH, temperature and NaCl. The effects of biosurfactant addition in the bioremediation can be known from the increasing of the microbial heterotrophic total count (cfu/g-soil) and the decreasing of the oil residue (g/g-soil). The type of the research was experimental with 3 controls, including non sterile soil without biosurfactant (KI), sterile soil without biosurfactant (KII), non sterile soil with biosurfactant at CMC level (KIII) and 4 treatment, including non sterile soil with adding of microbial consortium without biosurfactant (B0), non sterile soil with adding of microbial consortium and biosurfactant below the CMC (B1), non sterile soil with adding of microbial consortium and biosurfactant at CMC level (B2), and non sterile soil with adding of microbial consortium and biosurfactant above the CMC (B3). The incubation times were 0, 2, and 4 weeks respectively.The resulted data of the logarithm microbial total count and the crude oil residue (g/g-soil) were analyzed descriptively and statistically by two-way analysis of variances (two-way ANOVA) and Duncan test (p=0.05). The results of this research indicated that Pseudomonas putida T1-8 had CMC value about 665 ppm using ammonium sulfate precipitation methode, formed microemulsion about 53.34% using solar test, and stable at the variety of temperature, pH and salinity. Adding of biosurfactant gave an effect on bioremediation process. Biosurfactant at CMC value was known to be the most effective to increase microbial growth and to decrease the oil residue about 12.68%, if compared with the control at final incubation time (fourth week)