Bioremediation of Contaminated Soil with Crude Oil Using Consortium of bacteria

TL;DR

This study isolates and characterizes bacteria from contaminated soils, develops a bacterial consortium, and demonstrates its effectiveness in biodegrading crude oil hydrocarbons for soil bioremediation.

Contribution

It identifies specific bacterial strains capable of degrading crude oil and creates a consortium with high biodegradation efficiency for use in bioremediation.

Findings

Bacterial isolates degraded up to 75% of hydrocarbons.

The consortium showed higher degradation efficiency than individual strains.

Genetic identification confirmed Bacillus species involved in degradation.

Abstract

This study included isolate petroleum hydrocarbons degradable bacteria and develops a consortium or a mixture of bacteria with high biodegradation capabilities which can be used in biological treatment units of the contaminated soils before release. In this studyt ten bacterial strains were isolated from soils contaminated with crude oil, by primary and secondary screening, and by using the sterile saline solution with 1% of crude oil, five bacterial isolates that can degrade oil were identified. The bacterial isolates were isolated from polluted soils with crude oil, the samples were collected from different areas of the Baiji refinery, and samples of heavy crude oil extracted from Qayyarah fields were used in designing the biodegradation experiments, the five isolates were diagnosed based on phenotypic, culture and biochemical characterizes, and detection of the gene sequence of bacterial isolates (16SrRNA). The (16SrRNA) gene sequence of the bacterial isolates was recorded under the accession numbers LC596402, LC596403, LC596406, LC596404, LC596405, for the genus (AM-I-1, AM-I-2, AM-I-5) and the species (AM-I-3, AM-I-4) that following Bacillus Sp respectively, in the NCBI's GenBank, the efficiency of the five isolates were examined for utilizing petroleum hydrocarbons using a sterile mineral salt medium MS supplemented with crude oil as the sole source of carbon with different concentrations, the results showed that the decomposition of petroleum hydrocarbons at the concentrations (0.5, 1, 1.5, 2, 3) % reached (57.32, 69.36,63.71, 75.20, 68.60) %, respectively, for mixed isolates, depending on the results of the gas chromatography (GC) analysis.