Abstract:
Bioremediation has received a great deal of attention, and bacteria isolated from polluted soil
can be used in bioremediation process. The Jaffna peninsula depends to a great extent on
groundwater resources for domestic as well as agricultural purposes. On several instances it was
pointed out that, the groundwater is deteriorating due to over misuse and it is polluted by the
excessive usage of agrochemical, fertilizers, and improper disposal of waste oil and sewage. Hence
an experimental study was undertaken to isolate the oil degrading bacteria from natural
environment to facilitate the biodegradation to degrade the waste oil contamination site. Soil
samples were collected from oil contaminated site as near to automobile service station, Kondavil,
Jaffna. Inoculum was prepared and incubated in the culture media, which grow on a medium with
oil as the sole carbon source. Colonies were separated based on their morphological characters with
the help of microscope. Isolated bacterial strains were identified through gram staining, motility,
aerobic and anaerobic growth. For further classification and identification, biochemical tests were
done. From the contaminated soil, 10 morphologically different bacterial strains were isolated and
strains were identified as Pseudomonas alcaligenes, Micrococcus spp, Bacillus subtilis,
Pseudomonas stuzeri, Streptococci pyogenes, Bacillus megaterium, Pseudomonas mendocina,
Bacillus firmus, Bacillus cereus and Acinetobactor spp. The results revealed that crude oil
degrading bacteria from soil environments have a high level of diversity and variable
biodegradation abilities. Oil degrading bacteria can be isolated from oil-polluted sites. These
bacteria are indigenous in the polluted sites and they are responsible for the degradation of oil.
These isolated bacteria could be used for bioremediation effectively in the oil-contaminated sites.
Further studies are required to identify the cocktail of selected bacterial strains to efficiently
carryout bioremediation of the contaminated soil and effluents from the automobile service
stations.
