Potensi Bakteri dari Tempat Pelelangan Ikan (TPI) Bagan Percut Kabupaten Deli Serdang dalam mendegradasi Minyak Solar

Abstract

The activities of fishing boats at the Bagan Percut Fish Auction Place (TPI), Deli Serdang Regency, which often results in oil spills, is a problem that required to be addressed further regarding its consequences. This research aims to obtain bacterial isolates from diesel oil-polluted water that are capable of decomposing and consuming diesel oil for their growth. Isolation was carried out on Bushnell Hass Agar (BHA) medium added with 200 ppm diesel oil as the only carbon source. The growth colonies were purified and characterized. There were 19 bacterial isolates capable of metabolizing diesel oil and producing biosurfactants. The screening of biosurfactant activities was based on Emulsification Index (EI24) value. Among 19 isolates tested, the best one had EI24 of 43.4 with isolate codes BAP 11 while the lowest one was 1.1 by BAP 4. Microscopic observation of the biosurfactant structure showed that isolate with high EI24 had a round shape and showed a high density compared to isolate with low EI24 values. The 5 isolates showing the highest biosurfactant activities were selected for further analysis, diesel oil degradation test. The medium was Bushnell Hass Broth (BHB) with the addition of 200 ppm diesel-oil and was incubated for 15 days. The parameters observed were the isolate growth, and reduction of diesel oil concentration. The growth test on Plate Count Agar medium showed that the BAP 11 isolate was the isolate with the highest number of colonies; 65 x 106 cells/ml on the day 15. The highest percentage of diesel oil reduction were BAP 11 and BAP 14 isolates at 84% and 70% respectively, while the control there was a decrease in diesel oil concentration of 5% on the 15th day. This indicated that BAP 11 and BAP 14 isolates had potential to be further developed as agents of bioremediation, especially the decomposition of hydrocarbon compounds.