Hydrocarbon and Dye Degradation by Actinomycetes from Flooded Soils

Abstract

Hydrocarbon and dye pollutants could exert adverse effects to the polluted surroundings and their occurrences are often anthropogenic. The presence of both pollutants could endanger the environment if there are no preventive and corrective measures taken. Fifteen actinomycete strains were used for potential application on hydrocarbon degradation and 10 strains used for dye degradation study. Kerosene, petrol and diesel were introduced to the actinomycetes in separate media as source of carbon and energy. Seven actinomycete strains were able to grow well on hydrocarbon growth medium and they showed notable changes in terms of number and size of colonies formed, formation of mycelia and the colour of colonies formed. Four actinomycetes that grow well on hydrocarbon medium were further cultivated in MSM liquid media supplemented with hydrocarbon. Optical density (OD) of culture media was measured as an indicator of actinomycete growth. Strain D053 and D25.2 showed higher trend of overall OD measurement. Although OD measurement is lower, the growth of Strain KSJ12.7 and D13.5 were observed where tiny cell cluster or cellular flocs were formed. Kerosene and diesel were found to be good growth substrate for the actinomycetes. For dye degradation, the decrease in absorbance will determine the percentage of decolourization of Congo Red achieved by actinomycete strains. Highest decolorization of Congo Red recorded by Strain D4 in ISP-1 at 79.22%, whereas Strain D008 in MSM at 8.88%. These two different media indicated that actinomycete strains need additional sources of carbon and nitrogen and did not only depend on the dye as their sole carbon and nitrogen sources. This study showed that actinomyctes could potentially be used in hydrocarbon and dye degradation given their ability to grow in both.