Identification, Purification, and Optimization of Copper-Resistant Acinetobacter sp. for Crude Oil Biodegradation

The present study aimed to isolate and identify bacteria resistant to copper ions (Cu²⁺) and capable of degrading crude oil from the vicinity of a copper mine. The optimal conditions affecting the biodegradation of crude oil in the presence of Cu²⁺ were also investigated. Herein, a unique strain with the ability to biodegrade crude oil and tolerate Cu²⁺ was isolated and purified. Identification results showed that the mentioned strain was most similar to Acinetobacter sp. and was designated as ZA-۱. Based on the findings, using crude oil as the sole source of carbon and energy, compared to bacterial growth in nutrient broth, leads to a decrease in the strain's tolerance to Cu²⁺. Based on the results of ANOVA and the rate of crude oil biodegradation by strain ZA-۱, it was determined that all factors studied except NH₄Cl concentration had a significant effect on the crude oil biodegradation process. The optimal conditions for crude oil biodegradation were determined to include pH=۸, temperature=۳۰ °C, salinity=۳۰ g/L, and NH₄Cl concentration of ۱.۵ g/L. Strain ZA-۱ was able to biodegrade ۳۰.۷۰% of crude oil. Considering the ability of the purified strain to degrade crude oil and tolerate Cu²⁺, the results of this study can be utilized in biological treatment processes for wastewater containing Cu²⁺ and contaminated with petroleum compounds.

کلیدواژه ها:

Acinetobacter ، Biodegradation ، Bacterial strain ، Crude Oil ، Taguchi approach