Potensi Bakteri dari Tempat Pelelangan Ikan (TPI) Tanjung Beringin Kabupaten Serdang Bedagai dalam Mendegradasi Minyak Solar

Abstract

Diesel oil degrading bacteria could be found in various habitats in the marine environment, including in the waters around fish auction sites (TPI). The high level of shipping activity at the Tanjung Beringin Fish Auction Site (TPI), Serdang Bedagai Regency, has resulted in the volume of oil waste contributed to the increase. One effort to overcome this problem appropriately without damaging the environment is by using bacteria that are capable of degrading diesel oil. This research aims to obtain bacterial isolates from polluted waters that were capable of degrading. In this study, 21 bacterial isolates were obtained which were successfully isolated using Bushnell Hass Agar (BHA) medium enriched with 200 ppm diesel oil as a carbon source. The 21 bacterial isolates were characterized and screened based on their biosurfactant activity, which were represented by Emulsification Index (EI₂₄) value. The best isolate with the highest EI₂₄ was shown by isolate BAT 19 while the lowest one was isolate BAT 2 with the EI₂₄ value were 53,21 and 1,06 respectively. The emulsion beads of the highest EI₂₄ was observed microscopialy. Its structure showed irregular shape with bigger size while the lowest EI₂₄ emulsion beads had more regular shape and smaller size. Further testing was carried out on 5 selected isolates based on the highest EI₂₄ value. Diesel oil decomposition test carried out using Bushnell Hass Broth (BHB) medium with the addition of 200 ppm diesel oil with an incubation time of 15 days at a temperature of 27°C. The parameters observed were isolate growth and reduction in diesel oil residue. The growth bacteria was measured using Standard Plate Count method with the highest number of colonies was shown by isolate BAT 19 which was 8.7 × 10⁷ cells/ml on day 15. The biodegradation of diesel oil test showed that two isolate, BAT 19 and BAT 2 had the highest percentage of reduction which were 91% and 73% respectively. The results indicated that BAT 19 and BAT 2 isolates have the potential to be further developed as bioremediation agents for hydrocarbon compounds, especially diesel oil.