Characterization of two bacterial strains isolated from wastewater and exhibiting in-vitro degradation of diesel and used oils

Abstract

Currently, pollution caused by petroleum products remains a critical concern. Among the various methods employed, bioremediation is the most widely utilized technique to address this issue. To implement this technique, we must continue to research and identify strains of microorganisms capable of degrading these pollutants. Thus, this study aimed to identify and test the biodegradation capacity of two bacterial strains. For this, morphological and biochemical characterization was done using standard methods. Then, a genetic characterization was performed by sequencing the 16S rRNA gene. The biodegradation capacity of the strains was determined according to the gravimetric method. All the morphological, biochemical and genetic characteristics obtained showed that the S2 and S7 strains belong to Acinetobacter calcoaceticus and Pseudomonas aeruginosa species, respectively. The biodegradation study showed that the two strains could degrade the substrates tested (diesel, SAE (Society of Automotive Engineers) 40 and SAE 50 used oils). It also revealed that the combination of strains degrades the tested products better than those used alone. Finally, this study indicated that the biodegradation of diesel by these strains is significantly greater than that of used oils (p<0.0001).