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

Caro, Ainhoa; Boltes, Karina; Letón, P. Fernández; García‐Calvo, Eloy

doi:10.1007/s10532-007-9165-z

Cited by 26 publications

(14 citation statements)

References 45 publications

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“…Indeed, some DBT C-Sdegrading bacteria were detected, among which Stenotrophomonas NISOC-04 and Microbacterium NISOC-06 [22] were the most important considering the rate at which they utilized DBT. High extent of gasoline tolerance and desulfurization supported the strains as catalyst candidates for biphasic systems [28].…”

Section: Discussionmentioning

confidence: 97%

C–S Targeted Biodegradation of Dibenzothiophene by Stenotrophomonas sp. NISOC-04

Papizadeh

Ardakani

Motamedi

et al. 2011

Appl Biochem Biotechnol

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Crude oil-contaminated soil samples were gathered across Khuzestan oilfields (National Iranian South Oil Company, NISOC) consequently experienced a screening procedure for isolating C-S targeted dibenzothiophene-biodegrading microorganisms with previously optimized techniques. Among the isolates, a bacterial strain was selected due to its capability of biodegrading dibenzothiophene in a C-S targeted manner in aqueous phases and medium mostly consisting of separately biphasic water-gasoline. The 16S rDNA of the isolate was amplified using eubacterial-specific primers and then sequenced. Based on sequence data analysis, the microorganism, designated NISOC-04, clustered most closely with the members of the genus Stenotrophomonas. Gas chromatography indicated that Stenotrophomonas sp. NISOC-04 utilizes 82% of starting 0.8 mM dibenzothiophene within a 48-h-long exponential growth phase. Growth curve analysis revealed the inability of Stenotrophomonas sp. NISOC-04 to utilize dibenzothiophene (DBT) as the exclusive carbon or carbon/sulfur source. Gibbs' assay showed no 2-hydroxy biphenyl accumulation, but HPLC confirmed the presence of 2-hydroxy biphenyl as the final product of DBT desulfurization. Under sulfur starvation, Stenotrophomonas sp. NISOC-04 produced a huge biomass with untraceable sulfur and utilized atmospheric insignificant sulfur levels.

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Section: Discussionmentioning

confidence: 97%

C–S Targeted Biodegradation of Dibenzothiophene by Stenotrophomonas sp. NISOC-04

Papizadeh

Ardakani

Motamedi

et al. 2011

Appl Biochem Biotechnol

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“…Several researchers have studied the BDS process in the presence of synthetic oil fractions or pure hydrocarbons (Caro et al, 2007;Finnerty, 1993;Jia et al, 2006;Li et al, 2007b, c;Ohshiro & Izumi, 1999;Rhee et al, 1998). Clearly, the investigation of the biodesulfurization of organosulfur compounds in the presence of pure hydrocarbon provides a valuable background to the study of the biodesulfurization of crude oil fractions.…”

Section: Biodesulfurization Of Crude Oil and Its Fractionsmentioning

confidence: 99%

Biocatalytic desulfurization (BDS) of petrodiesel fuels

2008

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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. However, HDS has several disadvantages, in that it is energy intensive, costly to install and to operate, and does not work well on refractory organosulfur compounds. Recent research has therefore focused on improving HDS catalysts and processes and also on the development of alternative technologies. Among the new technologies one possible approach is biocatalytic desulfurization (BDS). The advantage of BDS is that it can be operated in conditions that require less energy and hydrogen. BDS operates at ambient temperature and pressure with high selectivity, resulting in decreased energy costs, low emission, and no generation of undesirable side products. Over the last two decades several research groups have attempted to isolate bacteria capable of efficient desulfurization of oil fractions. This review examines the developments in our knowledge of the application of bacteria in BDS processes, assesses the technical viability of this technology and examines its future challenges. IntroductionBiotechnology is now accepted as an attractive means of improving the efficiency of many industrial processes, and resolving serious environmental problems. One of the reasons for this is the extraordinary metabolic capability that exists within the bacterial world. Microbial enzymes are capable of biotransforming a wide range of compounds, and the worldwide increase in attention being paid to this concept can be attributed to several factors, including the presence of a wide variety of catabolic enzymes and the ability of many microbial enzymes to transform a broad range of unnatural compounds (xenobiotics) as well as natural compounds. Biotransformation processes have several advantages compared with chemical processes, including: (i) microbial enzyme reactions are often more selective; (ii) biotransformation processes are often more energy-efficient; (iii) microbial enzymes are active under mild conditions; and (iv) microbial enzymes are environment-friendly biocatalysts. Although many biotransformation processes have been described, only a few of these have been used as part of an industrial process. Many opportunities remain in this area.Petroleum biotechnology is based on biotransformation processes. Petroleum microbiology research is advancing on many fronts, spurred on most recently by new knowledge of cellular structure and function gained through molecular and protein engineering techniques, combined with more conventional microbial methods. Current applied research on petroleum microbiology encompasses oil spill remediation, fermenter-and wetland-based hydrocarbon...

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“…In other studies, the effect of exogenously added HBP on the BDS process has been described. R. erythropolis IGTS8 aqueous resting-cell suspensions of 2 g DCW/liter were prepared and supplied with only one of the 4S pathway compounds (either DBT, DBTO, DBTO 2 , or HBPS) (13). HBP was also added at concentrations of either 0 or 50 M in each experiment.…”

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confidence: 99%

Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization

Abín-Fuentes

Mohamed

Wang

et al. 2013

Appl Environ Microbiol

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Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubating Rhodococcus erythropolis IGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 M with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC 50 s) for DszA, DszB, and DszC were measured to be 60 ؎ 5 M, 110 ؎ 10 M, and 50 ؎ 5 M, respectively. The fact that the IC 50 s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation. Biodesulfurization (BDS) is a process in which microorganisms, typically, bacteria, are used to reduce the level of sulfur in fuels derived from crude oil, including diesel and gasoline. Over the last 20 years, interest in BDS as an alternative to hydrodesulfurization (HDS), which is the current desulfurization standard in the oil industry, has increased. HDS uses a metal catalyst along with hydrogen gas (H 2 ) at high temperature and pressure to remove sulfur from organic sulfur compounds and generate H 2 S gas (1). Major drawbacks of HDS include steric hindrance of the metal catalysts by certain recalcitrant compounds and large energy consumption due to process operation at high temperature and pressure (1). Recalcitrant compounds include the parent molecule dibenzothiophene (DBT) and some of its alkylated derivatives, such as 4-methyldibenzothiophene (4-DBT) and 4,6-dimethyldibenzothiophene (4,6-DBT). BDS can potentially be used to remove the sulfur that cannot be removed by HDS, though it is likely not a replacement for the current HDS infrastructure. The use of more than one desulfurization technology may be necessary to meet the increasingly stringent sulfur regulations (1).There is a wide range of microorganisms known to have BDS capability (2). Such microorganisms typically desulfurize DBT by one of two pathways: the Kodama pathway or the 4S pathway (1). The Kodama pathway i...

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

Cited by 26 publications

References 45 publications

C–S Targeted Biodegradation of Dibenzothiophene by Stenotrophomonas sp. NISOC-04

C–S Targeted Biodegradation of Dibenzothiophene by Stenotrophomonas sp. NISOC-04

Biocatalytic desulfurization (BDS) of petrodiesel fuels

Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization

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