Investigation on indigenous bacteria for individual BTEX degradation potentials and relative pathways used

Download
2018
Yavaş, Alper
Monoaromatic hydrocarbons including benzene, toluene, ethylbenzene and xylene collectively called as BTEX are found in the composition of crude oil and gasoline as an additive and thought to be the most serious contaminants of soil and groundwater. It is expected that indigenous bacteria isolated from petroleum hydrocarbon contaminated sites probably have degradation potential for the BTEX compounds. In this study, out of 22, 19 bacterial strains were selected as potential degraders for at least one of the BTEX compounds. The degradation abilities of the bacterial strains were determined by using HS-GC/MS and 9 bacterial strains namely R. plancticola Ag11, S. aureus Ba01, S. nematodiphila Ba11, A. calcoaceticus Fe10, P. koreensis Hg10, P. koreensis Hg11, S. nematodiphila Mn11, A. johnsonii Sb01 and M. luteus Sr11 were chosen as efficient degraders for pathway analyses. Polymerase Chain Reaction (PCR) was first performed for the detection of catabolic genes. PCR results revealed that most of the bacterial strains harbored the todC1 gene and only two of them carried the tbmD gene. To evaluate biodegradation pathways, BTEX intermediates produced during degradation were also analyzed by using GC/MS. The results showed that monooxygenation pathway was more common within bacterial strains although dioxygenation genotype (todC1) was more prevalent. Intermediate analyses and PCR-detection of catabolic genes revealed that benzene was degraded by R. plancticola Ag11 and M. luteus Sr11 through monooxygenation pathway. Toluene was metabolized through side chain monooxygenation pathway by the strain A. calcoaceticus Fe10 and ring monooxygenation pathway by the strain M. luteus Sr11. During ethylbenzene degradation by R. plancticola Ag11, P. koreensis Hg11 and S. nematodiphila Mn11 styrene pathway was mainly used. Comparison of PCR-detection and intermediate analysis results led to conclude that new primer sets were required to detect all possible subfamilies of the ring hydroxylating monooxygenase and side chain monooxygenase genes. The study revealed five efficient bacterial strains namely R. planticola Ag11, A. calcoaceticus Fe10, P. koreensis Hg11, S. nematodiphila Mn11 and M. luteus Sr11 with their corresponding pathways for aerobic degradation of the individual BTEX compounds.

Suggestions

Indigenous hydrocarbon degraders further evaluated for their kerosene degradation and biosurfactant production potentials
Aydın, Dilan Camille; İçgen, Bülent; Department of Biochemistry (2018)
Kerosene, known as jet fuel, is one of the most spilled petroleum product causing serious environmental problems due to recalcitrant compounds found in its structure. The only eco-friendly solution for this problem is bioremediation, in which bacteria are used for the degradation and transformation into non or less toxic forms. The efficiency of this process depends not only on biodegradation ability of the bacterial isolates used but also on their biosurfactant production abilities. Therefore, in this stud...
Evaluation of adsorbents with passive sampling and their analytical methods to determine volatile organic compunds emitted from vehicular exhaust
Civan, Mihriban; Tuncel, Süleyman Gürdal (2012-09-01)
In order to accurate and precise determination of Volatile Organic Compounds (VOCs) from vehicular emissions were developed method including a) adsorption of VOCs on different adsorbents followed by thermal desorption and gas chromatography (GC) with flame ionization detector (FID) quantification, b) validation of the sampling and analytical method. The adsorption efficiency of Tenax and Chromosorb 106 adsorbents were eveluated for 104 VOCs to select of adequate sorbent for passive sampling. Since most of t...
A study of thin film solid phase microextraction methods for analysis of fluorinated benzoic acids in seawater
Boyacı, Ezel; Viteri, C. Ricardo; Pawliszyn, Janusz (2016-03-04)
Fluorinated benzoic acids (FBAs) are frequently used as tracers by the oil industry to characterize petroleum reservoirs. The demand for fast, reliable, robust, and sensitive approaches to separate and quantify FBAs in produced water, both in laboratory and field conditions, has not been yet fully satisfied. In this study, for the first time, thin film solid phase microextraction (TF-SPME) is proposed as a versatile sample preparation tool for the determination of FBAs in produced water by pursing two diffe...
Evaluation of adsorbents with passive sampling and their analytical methods to determine volatile organic compounds emitted from vehicular exhaust
CİVAN, MİHRİBAN; Tuncel, Süleyman Gürdal (2012-04-01)
In order to accurate and precise determination of Volatile Organic Compounds (VOCs) from vehicular emissions were developed method including a) adsorption of VOCs on different adsorbents followed by thermal desorption and gas chromatography (GC) with flame ionization detector (FID) quantification, b) validation of the sampling and analytical method. The adsorption efficiency of Tenax and Chromosorb 106 adsorbents were eveluated for 104 VOCs to select of adequate sorbent for passive sampling. Since most of t...
Catabolic genes dependent detection of aerobic BTEX degraders
Yavas, Alper; İçgen, Bülent (null; 2017-11-14)
Monoaromatic hydrocarbons, including benzene, toluene, ethylbenzene and xylene, collectively called BTEX, are major components of gasoline and are thought to be the most significant contaminants of soil and groundwater due to frequent leakages from underground storage tanks and accidental spills. Degradation of BTEX compounds by bacteria is known to be one of the most efficient ways to remove these compounds from soil and groundwater. There have been extensive studies demonstrating that BTEX degradation is ...
Citation Formats
A. Yavaş, “Investigation on indigenous bacteria for individual BTEX degradation potentials and relative pathways used,” M.S. - Master of Science, Middle East Technical University, 2018.