Biodegradation of Diesel Oil by Microorganisms Isolated from Diesel Oil Contaminated Site

초록

Most widely used environmental remediation technology for diesel oil contamination is bioremediation since diesel oil has low water solubility and volatility. In this study, aerobic strains were isolated from diesel oil contaminated site. Isolates were tested for their ability to grow on diesel by culturing them on the culture medium that contains diesel oil as a major carbon source. Among them two different colonies were separated. The two colonies, one is white and the other is yellow, grew well in diesel-containing containing culture broth. The white colony, yellow colony, and both white and yellow colonies, were grown on minimal salt media including diesel to determine the degree of deisel degradability. Changes of biodegradation abilitywith various inoculum sizes, diesel concentrations, and salt concentrations were analyzed by gas chromatography. When the two strains were cultured separately, white coloby forming cells grew faster than yellow colony formming strain was higher. When those two strains were cultured together, much higher degradability was obtaind. Mixed culture of white and yellow coloby forming strains grew well with 1% diesel oil concentration and their growth was not much influenced by the increase of NaCl concentration. Addition of growth nutrient enhanced the diesel degradability. When additional nitrogen source was applied, higher diesel degradability (over 90%) was obtainde compared with that without additional nitrogen source.