Optimization of Crude Oil Bioremediation by Alcanivorax dieselolei in Aquatic Medium Using Taguchi Method

Seeping oil and oily waste into the seas can cause serious damage to aquatic life. These compounds tend to bioaccumulate and threaten human health, Therefore, it is important to develop efficient methods for the treatment of these compounds. In this study, sediment and water from different regions of the Persian Gulf (Bandar Abbas) were sampled and enriched in mineral salt medium. The most efficient crude oil degrading bacteria was purified and then identified by molecular (16S rDNA) and biochemical analysis. The Taguchi experimental design L16 (45) was used to optimize the biodegradation process of crude oil by the isolated strain. This investigation applied the parameters of pH, temperature, optical density and concentration of NH4Cl and K2HPO4. The results showed that isolated strain had 99% similarity to Alcanivorax dieselolei and named TA1. Temperature and pH had the greatest influence on crude oil biodegradation. Maximum biodegradation efficiency was predicted to occur at pH= 9, temperature = 35 ͦC, NH4Cl (g/L)= 1, K2HPO4 (g/L)= 0.25 and optical density (OD)= 0.1. Under these conditions more than 80% of crude oil was degraded. Due to high ability of isolated strain to degrade crude oil, the results of this study can be used in the bioremediation of petroleum contaminated soil in the studied area.