Enrichment of Potential Halophilic Marinobacter Consortium for Mineralization of Petroleum Hydrocarbons and Also as Oil Reservoir Indicator in Red Sea, Saudi Arabia

Abstract

The present study was conducted to reveal specific bacterial consortium belong to same genus capable of mineralizing petroleum hydrocarbons and also act as a valid indicator to locate the oil reservoir in Red Sea, Saudi Arabia. The study focused on area consist of hydrocarbons in briny water and sediment. The sites included Port Sudan Deep, Suakin Deep, Hatiba Deep, and Brian salt in the Red Sea, Saudi Arabia. The concept of the study is to identify crude oil reservoir using the presence of hydrocarbon degrading bacterial strains. The Marinobacter strains isolated were grown in different media such as marine broth with crude oil, tryptic soy agar and mineral salt medium with phenanthrene as sole carbon source at 40 g/L of NaCl concentration. The strains present in hydrocarbon reservoirs of different deeps were isolated and identified as Marinobacter hydrocarbonoclasticus strain MAM1 (MF716467), Marinobacter sp. strain MAM2 (MF716468) and Marinobacter hydrocarbonoclasticus strain MAM3 (MF716469). Marinobacter consortium was pertained by the mixture of the above strains (MAM1, MAM2 and MAM3) from different deep samples. The consortium potentially utilized PAHs (polycyclic aromatic hydrocarbons) such as phenanthrene (PHN) and pyrene (PY). The consortium degraded 72 ± 1.5% of PHN at 1500 mg/L concentration in 16 days under saline condition (4%). The degradation of PY (300 mg/L) by the consortium was 86 ± 1.1% in 12 days under saline condition (4%). Also the presence of Marinobacter strains in the deep water samples and crude oil drilling rig (core) samples, confirmed the relationship between the bacterial strains and oil reservoir. Thus the study confirmed Marinobacter can be used as a potential indicator strain in different deeps at Red Sea to identify the crude oil reservoir.