Bacterial strains diversity in contaminated soils and their potential for bioremediation of total petroleum hydrocarbons in south west of Iran.

Purpose: The main purpose of this research was investigating of bioremediation potential oily contaminated soils using native bacterial strains in an oil field.

Methods: In this research, total bacterial consortium were identified in oily soils with sandy loam texture as case and non-contaminated soils as controls during six months. The dominant strains present on contaminated soil were identified by DNA extraction using 16S rDNA gene sequencing via NGS technique and compared with bacteria present in non-contaminated soil as control samples.

Comparison of performance and efficiency of four methods to extract genomic DNA from oil contaminated soils in southwestern of Iran.

The wide spectrum of oil industry activities caused soil contaminants, as environmental concern in many areas of the world. Bioremediation of oily soils, as biological approach done by bacteria and fungi, is very important to eliminate this pollution. In this study four different metagenomic protocols for DNA extraction has been tested in order to sequence and identify the native bacterial species involved in remediation of oily soils.

Enhancement of bio-desulfurization capability of a newly isolated thermophilic bacterium using starch/iron nanoparticles in a controlled system.

Due to the increasing application of oil and petroleum products, increased environmental contamination has become a matter of concern. Bio-desulfurization process may be used to eliminate sulfur from fossil fuels in the moderate condition. In this study, a thermophilic bacterium was isolated that was able to desulfurize dibenzothiophene.

Pyrene removal from contaminated soils by modified Fenton oxidation using iron nano particles.

Background: The problems related to conventional Fenton oxidation, including low pH required and production of considerable amounts of sludge have led researchers to investigate chelating agents which might improve the operating range of pH and the use of nano iron particle to reduce the excess sludge. The pyrene removal from contaminated soils by modified Fenton oxidation at neutral pH was defined as the main objective of the current study.

Methods: Varying concentrations of H2O2 (0-500 mM) and iron nano oxide (0-60 mM), reaction times of 0.

Efficient breaking of water/oil emulsions by a newly isolated de-emulsifying bacterium, Ochrobactrum anthropi strain RIPI5-1.

Water-oil emulsions occur throughout oil production, transportation, and processing. The breaking of the water/oil emulsion improves oil quality and as a consequence chemically synthesized de-emulsifiers are commonly used in the petroleum industries. Microbial de-emulsifiers represent potential alternatives to the chemicals and may become important products for petroleum industries.

Analysis of petroleum biodesulfurization in an airlift bioreactor using response surface methodology.

For the first time, growing cells of Gordonia alkanivorans RIPI90A were used for biodesulfurization (BDS) of diesel. This process was carried out in an internal airlift bioreactor. BDS parameters (oil/water phase ratio and initial sulfur concentration) were optimized in flasks using response surface methodology.

Emulsification potential of a newly isolated biosurfactant-producing bacterium, Rhodococcus sp. strain TA6.

An indigenous biosurfactant producing bacterium, Rhodococcus sp. strain TA6 was isolated from Iranian oil contaminated soil using an efficient enrichment and screening method. During growth on sucrose and several hydrocarbon substrates as sole carbon source, the bacterium could produce biosurfactants.

Genomic structure and promoter analysis of the dsz operon for dibenzothiophene biodesulfurization from Gordonia alkanivorans RIPI90A.

The bacterium Gordonia alkanivorans RIPI90A has been previously reported as dibenzothiophene-desulfurizing strain. The present study provides a complete investigation of the dsz operon including dsz promoter analysis from desulfurization competent strain belonging to the genus Gordonia. PCR was used to amplify the dszABC genes and adaptor ligation-based PCR-walking strategy used to isolate the dsz promoter.

Biocatalytic desulfurization (BDS) of petrodiesel fuels.

Oil refineries are facing many challenges, including heavier crude oils, increased fuel quality standards, and a need to reduce air pollution emissions. Global society is stepping on the road to zero-sulfur fuel, with only differences in the starting point of sulfur level and rate reduction of sulfur content between different countries. Hydrodesulfurization (HDS) is the most common technology used by refineries to remove sulfur from intermediate streams.

Dimethyl sulfoxide (DMSO) as the sulfur source for the production of desulfurizing resting cells of Gordonia alkanivorans RIPI90A.

The sulfate repression of desulfurization (Dsz) phenotype represents a major barrier to the mass production of desulfurizing resting cells. This repression can be avoided by replacing sulfate with dibenzothiophene (DBT) as the main substrate for the 4S pathway. However, mass production of biocatalyst using DBT is impractical because of its high price, low water solubility, and growth inhibition by 2-hydroxybiphenyl (2-HBP), which is the end product of the 4S pathway.

Stabilization of water/gas oil emulsions by desulfurizing cells of Gordonia alkanivorans RIPI90A.

It has been previously reported that resting-cells, non-proliferating cells, of Gordonia alkanivorans RIPI90A can convert dibenzothiophene (DBT) to 2-hydroxybiphenyl (2-HBP) via the 4S pathway in a biphasic system. The main goal of the current work was to study the behaviour of resting-cells of this strain in biphasic organic media. Resting-cells showed strong affinity for sulfurous organic substrates and were able to stabilize water/gas oil emulsions by attaching to the interface without decreasing the surface tension of their environment.