Biodegradation of heptadecane in hydrocarbon polluted dune sands using a newly-isolated thermophilic bacterium, Brevibacillus borstelensis TMU30: statistical evaluation and process optimization

Abstract

An enrichment culture was established to isolate a thermophilic hydrocarbon-degrading bacterium from contaminated soil samples from the Tehran Petroleum Refinery. The bacterium was characterized based on 16S rRNA and identified as Brevibacillus borstelensis TMU30. It is registered at NCBI under accession number KF181624.1. The capability of the bacterium for degradation of heptadecane as a representative contaminant in polluted dune sand was evaluated in a slurry bubble column bioreactor. The aeration rate, inoculum content and pulp density were optimized to maximize the degradation of heptadecane using the central composite design of response surface methodology. The results showed that maximum heptadecane reduction reached 48% at an aeration rate of 62 ml min À1 , inoculum content of 9.3% (v/v) and pulp density of 63 g l À1 only after 4 days. This study highlights an important potential use of thermophilic degradative bacteria to eliminate contamination in a slurry bioreactor while shortening dramatically the treatment time.

The physical–biological processes of petroleum hydrocarbons in seawater/sediments after an oil spill

“…At 48 d, the oil concentration in tank A had reduced to 2.28 mg L À1 , which means that strain S-1 catabolized the crude oil as a carbon and energy source so it reduced the DPH content. 35,36 The degradation removal percentage of the DPHs was about 33.72%, including physical and chemical degradation such as weathering and catabolizing.…”

“…In this study because the emulsication of GM-2 caused the DPHs to increase, the crude oil in the sediment peaked at 21 d, which is consistent with the dispersant enhancing the sorption extent. 35 Dispersants make crude oil content decrease, but at the same time, they may increase oil pollution in tidal ats. Fig.…”

Hydrocarbon degradation by a newly isolated thermophilic Anoxybacillus sp. with bioemulsifier production and new alkB genes

“…4,14,17,18 Genera collected from these sites have been limited to Bacillus, Geobacillus, Thermoactinomyces, and Brevibacillus. 19,20 Only four studies on hydrocarbon degradation by Anoxybacillus have been reported, [21][22][23][24] where the degraded compounds were aromatic. As a new thermophilic genus, Anoxybacillus could be utilized in a large number of applications as previously described, 25 however these applications are currently limited to the hydrolysis of starch and lignocellulosic biomasses, not the degradation of alkanes.…”