Analysis of biodesulfurization of model oil system by the bacterium, strain RIPI-22

Rashtchi, M.; Mohebali, Ghasemali; Akbarnejad, Mohammad Mehdi; Towfighi, Jafar; Rasekh, Behnam; Keytash, A

doi:10.1016/j.bej.2005.08.034

Cited by 69 publications

(32 citation statements)

References 20 publications

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“…This value is the highest of those described previously in the literature, i.e., 21.6 (Davoodi et al, 2010), 11.9 (Martín et al, 2005), 8.9 (del Olmo et al, 2005, 3.6 (Alves and Paixao, 2014) and 2.1 (Rashtchi et al, 2006) μmol 2HBP produced/g DCW/h, when using microbial resting cell cultures in aqueous phase. Further research to increase bioconversion efficiencies may be focused on the problem of desulfurizing HBPS in medium broth.…”

Section: Enhancing Conversion Of Dbt Into 2hbp By Engineering Synthetmentioning

confidence: 53%

Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds

Martínez

Mohamed

Rozas

et al. 2016

Metabolic Engineering

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The 4S pathway is the most studied bioprocess for the removal of the recalcitrant sulfur of aromatic heterocycles present in fuels. It consists of three sequential functional units, encoded by the dszABCD genes, through which the model compound dibenzothiophene (DBT) is transformed into the sulfur-free 2-hydroxybiphenyl (2HBP) molecule. In this work, a set of synthetic dsz cassettes were implanted in Pseudomonas putida KT2440, a model bacterial "chassis" for metabolic engineering studies. The complete dszB1A1C1-D1 cassette behaved as an attractive alternative -to the previously constructed recombinant dsz cassettes -for the conversion of DBT into 2HBP. Refactoring the 4S pathway by the use of synthetic dsz modules encoding individual 4S pathway reactions revealed unanticipated traits, e.g., the 4S intermediate 2HBP-sulfinate (HBPS) behaves as an inhibitor of the Dsz monooxygenases, and oncesecreted from the cells it cannot be further taken up. That issue should be addressed for the rational design of more efficient biocatalysts for DBT bioconversions. In this sense, the construction of synthetic bacterial consortia to compartmentalize the 4S pathway into different cell factories for individual optimization was shown to enhance the conversion of DBT into 2HBP, overcome the inhibition of the Dsz enzymes by the 4S intermediates, and enable efficient production of unattainable high added value intermediates, e.g., HBPS, that are difficult to obtain using the current monocultures. IntroductionCrude oils contain undesirable contaminant molecules, such as thiophenic aromatics compounds, which have a negative impact on oil processing and pose serious environmental threats (Soleimani et al., 2007). A wide spectrum of desulfurization technologies have been developed to remove sulfur mainly from finished refinery products (Stanislaus et al., 2010). Hydrodesulfurization (HDS) treatment has proved to be the common technology of choice to reduce the level of sulfur in crude oil products.Significant environmental, technical and economic limitations have been reported in applying the HDS process (Babich and Moulijn, 2003).During the past 30 years, research to develop alternative desulfurization technologies resulted in a biotechnological strategy to eliminate sulfur from thiophenic compounds (biodesulfurization (BDS)) via serial reactions known as the 4S pathway (Gray et al., 2003;Gupta et al., 2005;Kilbane, 2006;Monticello, 2000;Nuhu, 2013; Xu et al., 2009). This pathway was firstly reported in the gram-positive bacteriumRhodococcus erythropolis IGTS8 (Gallagher et al., 1993), but the 4S pathway has been also found in other bacteria (Duarte et al., 2001;Kilbane, 2006;Mohebali and Ball, 2008).The 4S pathway provides a nondestructive oxidative process used by the cells to obtain the sulfur required for growth, which involves the transformation of dibenzothiophene (DBT), the model compound for sulfur heterocycles present in oil and refractory to HDS, into 2-hydroxybiphenyl (2HBP) and sulfite ( Fig. 1A) (Gallagher et al...

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Section: Enhancing Conversion Of Dbt Into 2hbp By Engineering Synthetmentioning

confidence: 53%

Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds

Martínez

Mohamed

Rozas

et al. 2016

Metabolic Engineering

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“…Nowadays, crude oils dependency becomes middledistillate fractions more important and great efforts and investments in desulfurization technologies have been developed (Rashtchi et al 2006). Hydrodesulfurization (HDS) is the technology used to desulfurize fuels, removing the sulfur in the presence of metallic catalysts, hydrogen gas and very high pressures and temperatures (H. del Olmo et al 2005a).…”

Section: Introductionmentioning

confidence: 99%

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

et al. 2007

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As several authors have reported previously, the Biodesulfurization of hydrodesulfurization recalcitrants, such as dibenzothiophene, is not yet commercially viable because mass transfer limitations and feedback inhibition effects are produced during the conversion. This work has been focused to investigate the inhibition process in aqueous and oil-water systems with two different aerobic biocatalysts types, Rhodococcus erythropolis IGTS8 and Pseudomonas putida CECT 5279. The results obtained have proven that global DBT desulfurization process using CECT 5279 was not clearly deactivated due to final product accumulation, under the experimental conditions assayed. Consistently, the desulfurization pattern has been described with the Michaelis-Menten equation, determining the kinetic parameters. On other hand, the assays have shown that important mass transfer limitations produced the decrease of the yields obtained with this Gram(-) strain in biphasic media. With strain IGTS8 it was observed lower mass transfer problems, but contrary the reaction was severely affected by the final product accumulation, in both aqueous and biphasic systems. Therefore it has been proposed an enzymatic kinetic model with competitive inhibition to describe the BDS evolution pattern when this Gram(+) strain was used.

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“…There was almost a 99% decrease in total sulfur level of DBT at 40 • C in 24 h. About 59% of total sulphur was removed from Liaoning crude oil after 72 h treatment. Various studies of % sulphur removal from petroleum distillates by BDS techniques are summarized in Table 2 and Figure 2, at optimum temperatures and DBT concentrations using different microorganisms [124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139]. The microorganisms are abbreviated as follow; Gordonia alkanivorans RIPI90A (GAR 190A), Gordonia alkanivorans strain 1B (GAS 1B), Rhodococcus erythropolis IGTS8 (RE IGTS8 …”

Section: Recent Studies In Bdsmentioning

confidence: 99%

Biodesulfurization of Petroleum Distillates—Current Status, Opportunities and Future Challenges

2017

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Sulfur oxide (SO 2 ) and hydrogen sulfide (H 2 S) are considered as one of the major air pollutants in the world today. In addition, high sulfur levels in petroleum distillates can promote the deactivation of catalysts through poisoning in fluidized catalytic cracking (FCC) during hydrocracking of the heavy distillates to lighter ones. The presence of high sulfur-containing compounds in the process streams could cause corrosion of piping and fittings and equipment, thereby damaging the pipelines and leading to air emissions of sulfur-containing compounds, which are undesirable for mankind and his environment. In many cases, a large quantity of SO x is released into the atmosphere when petroleum distillates that contain substantial amount of sulphur-containing compounds are used as fuel and combust. In this article, a short overview of different desulfurization methods that are employed to remove sulfur from petroleum distillates is provided. In particular, the review concentrates on biodesulfurization technique. In addition, this article intends to provide its readers current status of biodesulfurization (BDS). It critically analyses the trend in the development of the technology to showcase its strength and weakness that could pave a way for future opportunities. Approaches that are suitable to remediate sulfur-contaminated environment are discussed as well. Lastly, speculations on future directions or opportunities that require exploration are provided as a way of provoking the thoughts of researchers in this field.

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Analysis of biodesulfurization of model oil system by the bacterium, strain RIPI-22

Cited by 69 publications

References 20 publications

Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds

Engineering synthetic bacterial consortia for enhanced desulfurization and revalorization of oil sulfur compounds

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

Biodesulfurization of Petroleum Distillates—Current Status, Opportunities and Future Challenges

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