Assessing the biodegradation efficiency of bacteria isolated and characterized from crude oil-contaminated soil

Abstract

Oil pollution has serious effects on human health, and to remove or mitigate these negative effects, three bacterial strains were isolated from soil contaminated with crude oil collected from the Kasak refinery, west of Nineveh Governorate, at distances of (0, 20, 40, 60, 80) meters. The aim of the study is to evaluate the ability and efficiency of bacteria to analyze petroleum hydrocarbons to treat soil contaminated with crude oil. To be used in biodegradation experiments using crude oil, the bacterial isolates were identified according to their phenotypic characteristics and chemistry tests. The bacterial isolates were detected by genetic sequencing tests (16S rRNA), and they were registered with NCBI, which was registered under the special accession number for each bacterial isolate, the genus (BIAB1) with the number LC775009, the genus (BIAB2) with the number LC774612, while the genus (BIAB4) with the number LC774613. The use of two strains (BIAB1) and (BIAB2) in the study to evaluate the ability of bacteria to biodegrade using mineral salt media, by adding crude oil at specific concentrations (0.5%), (1%), (1.5%), (2%), and (3%) as a sole source of carbon. The results of the gas chromatography analysis showed that the best ability to analyze hydrocarbons by the two isolates BIAB1 and BIAB2 was at a concentration of (2%) with a rate of (96.42%, and 97.45%) respectively for a period of 12 days. The results revealed the extent of the efficiency of the bacteria in the Analysis of crude oil.