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We have to developed active microbial consortium that could be of higher degradation of crude oil contaminated groundwater, wastewater aeration pond and biopond at the oil refinery Terengganu Malaysia. Among four isolates that showed good growth only three different isolates (Acinetobacter faecalis WD2, Staphylococcus. sp DD3 and Neisseria elongate TDA4.) were selected based on the growth ability and degradation. Significant growth and effectiveness of hydrocarbon biodegradation of the bacterial consortium examined bacterial strains and their mixtures in both were observed after 5, 10 and 15 days of degradation. Gas chromatography showed that more than 96 and 98% degradation of total hydrocarbon by consortia sp respectively

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Biosurfactant produced by Pseudomonas aeruginosa UKMP14T was optimized by growing the isolate in mineral salt medium (MSM) supplemented with 1% (v/v) glycerol and 1.3 g/L ammonium sulphate with C/N ratio of 14:1. The culture medium was incubated at 37°C, with an agitation speed of 150 rpm for 7 days. P. aeruginosa UKMP14T produced biosurfactant at 0.8 g/L after 7 days incubation. Anthrone assay proved biosurfactant was glycolipid. The biosurfactant was characterized by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) in addition to Fourier transform infra-red (FT-IR), nuclear magnetic resonance (NMR) and electrospray ionization-mass spectrometry (ESI-MS). The SEM-EDX analysis indicated the presence of carbon and oxygen elements by 78% and 22% (atomic %), respectively. FT-IR absorption spectra indicated the functional groups of rhamnolipid were located at 3308. 46, 2922.91, 2857.09 and 1730.96 cm -1 . ESI-MS/MS analyses identified P. aeruginosa UKMP14T produced rhamnolipid with two fatty acids-nine congeners, L-rhamnosyl-L-rhamnosyl-β-hydroxydecanoyl-β-hydroxydecanoate (Rha-Rha-C 10 -C 10 ) (m/z 649) which formed the main compound. The critical micelle concentration (CMC) of this rhamnolipid was established at 30 mg/L (32 dynes/cm). The characteristics of biosurfactant produced by P. aeruginosa UKMP14T indicated it has a high potential in industrial dan bioremediation application. Keywords: biosurfactant, Pseudomonas aeruginosa, rhamnolipid, spectroscopic analysis, CMC value AbstrakBiosurfaktan dihasilkan oleh Pseudomonas aeruginosa UKMP14T dioptimumkan dalam medium garam mineral (MSM) yang ditambahkan dengan 1% (i/i) gliserol dan 1.3 g/L ammonium sulfat dengan nisbah C/N iaitu 14:1. Medium kultur ini dieram pada 37°C, dengan kelajuan goncangan pada 150 psm selama 7 hari. P. aeruginosa UKMP14T menghasilkan biosurfaktan sebanyak 0.8 g/L selepas 7 hari pengeraman. Asai antron membuktikan biosurfaktan terhasil adalah glikolipid. Biosurfaktan tersebut dicirikan oleh mikroskop pengimbasan elektron-spektroskopi tenaga serakan sinaran-X (SEM-EDX), dengan penambahan Infra-merah transformasi Fourier (FT-IR), resonan magnetik nuklear (NMR) daknn spektrometri jisim-pengionan elektrosemburan (ESI-MS). Analisis SEM-EDX menunjukkan kehadiran unsur karbon dan oksigen masing-masing sebanyak 78% dan 22% (% atomik). Spektrum penyerapan FT-IR menunjukkan kumpulan berfungsi ramnolipid pada 3308.46, 2922.91, 2857.09 dan 1730.96 cm -1 . Analisis ESI-MS/MS mengenalpasti P. aeruginosa UKMP14T menghasilkan ramnolipid dengan sembilan kongener-dua asid lemak, L-ramnosil-L-ramnosil-β-hidroksidekanoil-β-hidroksidekanoat (Rha-Rha-C 10 -C 10 ) (m/z 649) sebagai sebatian utama. Kepekatan misel kritikal (CMC) ramnolipid ini dikesan pada 30 mg/L (32 dynes/cm). Ciri-ciri biosurfaktan yang dihasilkan oleh P. aeruginosa UKMP14T menunjukkan ia mempunyai potensi tinggi untuk di aplikasi dalam industri dan bioremediasi.

Response surface analysis was conducted to optimize the concentrations of Tapis crude oil and duration of incubation in