Range finding test of crude oil on Bacillus subtilis and Pseudomonas putida

Crude oil spills are not unfamiliar when it comes to petroleum mining. Crude oil degradation in nature can be conducted using the help from microorganisms. Bacillus subtilis and Pseudomonas putida have been proven to have the ability to degrade crude oil hydrocarbons. Each bacterium has different resistance level for different kind of pollutant and concentration. Range finding test was used to determine the range of concentrations for a specific compound in toxicity test. The objective of this study was to determine whether B. subtilis and P. putida can live on various crude oil concentrations (0 %, 5 %, 10 % and 15 % (v/v)) using nutrient agar medium. The maximum concentration was 15 % (v/v) for crude oil using bioremediation treatment. The bacteria were obtained from a pure culture at ITS environmental remediation laboratory and the crude oil was obtained from one of PT. Pertamina oil refineries. The bacteria were incubated at 37 °C and were screened using comparison between 0 % and the other variations each day for 7 days. The result of the range finding test showed that both the bacteria can live at various concentrations, even 15 % (v/v). It was shown that both of them potentially have a capability to be used to degrade a considered heavily crude oil polluted area.