Abstract

Petroleum hydrocarbons are species of dangerous contaminants in nature. Scientists are looking for many years to find solution for removing contaminants from the soil and water environments. Today, the use of microorganism, for removing crude oil pollution from contaminated sites (bioremediation) is considered by scientists. The purpose of this research is to isolate and identify hydrocarbons degrading bacteria from Shiraz Refinery soil. In this study, nutrient agar (NA) and mineral salt agar (MM2) were used as basic cultures. Using the Techniques Replica plating, we transferred colonies on NA surface to the MM2 agar. For spraying hydrocarbons on the MM2 agar surface, we used spray plating technique. Finally we have identified different bacterial genera by using biochemical tests and morphological study. Upon examination on morphological studies and biochemical tests, it is determined that these strains belong to bacterial genera as follows: Bacillus, Corynebacterium, Staphylococcus, Streptococcus, Klebsiella, Escherichia, Acinetobacter, Alcaligenes, Shigella. Enterobacter. It is also discovered that these bacteria can break down Biphenyl, Naphthalene, Camphor and Phenenthrene. The results showed that Biphenyl, Naphthalene, Camphor and Phenanthrene were decomposed by 22, 23, 34 and 23%, respectively. Bacillus was 69% of the bacterial population and accounted as the most dominant bacterial genus. Statistical analysis showed that there is a significant relationship with the level of 0.05 among the station, the numbers, and the diversity of Gram-positive bacteria.

Key words: Degrading bacteria, camphor, bioremediation, Bacillus, Shiraz Refinery.