عنوان مقاله [English]
نویسنده [English]چکیده [English]
Background and Objectives: One of the most important environmental pollutants is petroleum compounds that contaminate aquatic ecosystems. Petroleum pollutants affect the aquatic and terrestrial ecosystems and caused the adverse change in them. Petroleum pollutants contain heavy metals and hazard compounds and will have harmful effects on the ecosystems and organisms. Aromatic polycyclic hydrocarbons (PAHs) from the oil derivatives, which are generally caused by human activity and high stability, and have multiple side effects (carcinogenic and mutagenic). Anthracene, a combination of tricycles aromatic hydrocarbon and exist in contaminated areas. Anthracene is one among the 100 most toxic aromatic compounds and therefore reducing of Anthracene is important. Some of environmental bacteria are used from PAHs as a source of carbon and energy and convert it to the other compounds and final products of degradation are carbon dioxide and water. Anthracene due to low solubility in water less direct effect of land and microbial degradation of the biotic and abiotic conditions must be optimized for analysis to microbial degradation have the greatest efficiency. Bacillus is belonging to spore forming bacteria and able to grow in improper environmental conditions and different species of Bacillus are extensively used in biotechnology research, including the production of biological products and reduce environmental pollutants. In other hand, bacillus species are capable to grow in simple environments with minimal nutrient and therefore to reduce environmental pollutants.
Materials and Methods: Sampling was done from river estuary sediment and had cultured in Minimal Salt Medium (MSM). Bacillus Spp. was one of the isolated bacteria from river sediment that identified by molecular technique. In next step, influence of pH, temperature and concentration of anthracene were surveyed on anthracene biodegradation by Bacillus spp during zero, 24 and 48 hours.
Results: The results showed that the optimized condition for biodegradation included pH= 7.5, 35◦C and 150 ppm of anthracene. Bacterial degradation of anthracene was increased with prolong of incubation time. Efficiency of bacillus sp for decomposition of anthracene was 42% during 48 hours. Conclusion: As regards to high potential of bacillus and also its survival in improper condition (spore – forming bacterium) can be used as biological tools for degradation of anthracene in oil contaminated regions. This method is an eco friendly way for removal of petroleum based pollutants and used the biological factors so it doesn’t have a negative effect on the environment. This method is recommended to remediation of petroleum polluted environment.