ILMU KELAUTAN September 2015 Vol 20(3):143-152 ISSN 0853-7291 *) Corresponding author © Ilmu Kelautan, UNDIP ijms.undip.ac.id DOI: 10.14710/ik.ijms.20.3.143-152 Diterima/Received: 03-04-2015 Disetujui/Accepted: 12-05-2015 Apa The Efficacy of Bioaugmentation on Remediating Oil Contaminated Sandy Beach Using Mesocosm Approach Yeti Darmayati 1,4* , Harpasis S. Sanusi 2 , Tri Prartono 2 , Dwi Andreas Santosa 3 dan Ruyitno Nuchsin 1 1 Research Center for Oceanography, Indonesian Institute of Sciences, Jakarta Jln. Jend. Gatot Subroto 10, Jakarta 12710 Indonesia 2 Faculty of Fisheries and Marine Sciences, Bogor Agricultural University, Bogor, Indonesia Jln. Agatis, Kampus IPB Dramaga Bogor 16680 Indonesia 3 Faculty of Agriculture, Bogor Agricultural University , Bogor, Indonesia Jln. Agatis, Kampus IPB Dramaga Bogor 16680 Indonesia 4 School of Post Graduate Studies, Bogor Agricultural University, Bogor, Indonesia Jln. Agatis, Kampus IPB Dramaga Bogor 16680 Indonesia Email: yeti.darmayati@yahoo.com Abstract Bioremediation is basically consists of two approaches, biostimulation and bioaugmentation. The efficacy of bioaugmentation for combating oil pollution in field application is still argued. The purpose of study was to evaluate the efficacy of bioaugmentation and to compare the affectivity of single strain and consortium application in remediating oil polluted sandy beach. Experimental study in a field has been conducted with two (2) treatments and one (1) control in three different plots. The treatmens were introduction of a single strain (Alcanivorax sp TE-9) and a consortium (Alcanivorax sp. TE-9, Pseudomonas balearica st 101 and RCO/B/08- 015) cultures into oil contaminated sediment. The experiment in mesocosm approach was taken place in Cilacap coast. Arabian light crude oil was used in the concentration of 100.000 mg.kg -1 sediment. Changes of oil concentration, bacterial density and pore water quality have been monitored periodically for 3 months. The result showed that oil degradation percentage and bacterial growth in both treatments were higher than in control. After 3 months, the percentage of oil degradation experiment in control, single strain and formulated consortium treatments were observed at 60.4%, 74.5% and 73.5%. It proves that bioaugmentation tehnique can enhance significantly oil biodegradation in sandy beach. The applications of bacteria in single or consortium culture give no different impact on their affectivity for bioremediation in Cilacap sandy beach. By data extrapolation it can be predicted that both of treatments able to reduce remediation time from 210 days into 135–137 days. Bioaugmentation can be proposed as a good solution for finalizing oil removing in Cilacap sandy beach when oil spilled occurred in this environment. Keywords: Bioremediation, bioaugmentation, oil, sandy beach, Alcanivorax, mesocosm, Cilacap Abstrak Efikasi Tehnik Bioaugmentasi dalam Memulihkan Pantai Berpasir Tercemar Minyak Menggunakan Pendekatan Mesokosm Bioremediasi pada dasarnya terdiri dari dua pendekatan yaitu biostimulasi dan bioaugmentasi. Teknik bioaugmentasi dalam menanggulangi pencemaran minyak di lapangan masih diperdebatkan efektivitasnya. Penelitian ini bertujuan untuk mengevaluasi efikasi tehnik bioaugmentasi serta membandingkan efektivitas kultur tunggal dan konsorsium dalam memulihkan pantai berpasir tercemar minyak. Studi eksperimental di lapangan telah dilakukan dengan menggunakan dua perlakuan dan satu kontrol di tiga plot berbeda, Perlakuannya adalah penambahan bakteri kultur tunggal (Alcanivorax sp TE-9) dan bakteri konsorsium (Alcanivorax sp. TE-9, Pseudomonas balearica st 101 dan RCO/B/08-015) ke dalam sedimen yang tercemar minyak. Eksperimen dengan pendekatan mesokosm dilakukan di pantai Cilacap. Minyak mentah ringan Arabia dengan konsentrasi 100.000 mg.kg -1 sedimen digunakan sebagai bahan cemaran. Perubahan konsentrasi minyak, kepadatan bakteri dan parameter lingkungan diamati secara periodik selama 3 bulan percobaan. Hasil penelitian menunjukkan bahwa persentase degradasi minyak dan densitas bakteri di sedimen perlakuan lebih tinggi daripada kontrolnya. Setelah 3 bulan eksperimen, persentase degradasi minyak pada kontrol, perlakuan kultur tunggal dan konsorsium masing-masing teramati 60.4%, 74.5% and 73.5%. Hal ini membuktikan bahwa