Crude oil degrading ability by marine and freshwater bacteria

Abstract

The extensive use of hydrocarbon can lead to the pollution of the environment which can give devastating impact to the abiotic and biotic components in the environment. Marine environment is the most concern areas as this area is the most susceptible area of pollutant. Thus, the study on bioremediation is carried out which use marine and freshwater bacteria to evaluate the efficiency of the bacteria to degrade the crude oil. The findings also found that four bacteria strains; Enterobacter sp., Psychrobacter sp., Brevibacterium sp. and Chromobacterium sp. USM2 shown good growth on crude oil agar. The number of colonies detected on crude oil agar shown no significant difference among each bacteria, whereby Chromobacterium sp. USM2 has shown the highest number of colony growth on crude oil agar (52 colonies). All four strains also have grown well in a basal salt medium enriched with the crude oil and glucose as carbon sources for them. The maximum growth of the bacteria in a crude oil treatment medium (1 ml) was 12.7±0.01 g/L by Brevibacterium sp. while in glucose treatment medium the maximum growth performed by Enterobacter sp. (15.8 ± 0.09) g/L. The study shows that the different carbon sources will yield different growth rate for each bacteria and the enrichment of nutrient in cultivation of bacteria will support the bacteria to grow well. Apart from the nutrient supply, other factors such as temperature for cultivation also considered as a limiting factor for the bacteria to grow. So, these four strains have proved that the effectiveness in degrading the crude oil where they use the crude oil as their sole carbon sources for growth.