Sulfur from benzothiophene and alkylbenzothiophenes supports growth of Rhodococcus sp. strain JVH1

Abstract

Rhodococcus sp. strain JVH1 was previously reported to use a number of compounds with aliphatic sulfide bridges as sulfur sources for growth. We have shown that although JVH1 does not use the three-ring thiophenic sulfur compound dibenzothiophene, this strain can use the two-ring compound benzothiophene as its sole sulfur source, resulting in growth of the culture and loss of benzothiophene. Addition of inorganic sulfate to the medium reduced the conversion of benzothiophene, indicating that benzothiophene metabolism is repressed by sulfate and that benzothiophene is therefore used specifically as a sulfur source. JVH1 also used all six isomers of methylbenzothiophene and two dimethylbenzothiophene isomers as sulfur sources for growth. Metabolites identified from benzothiophene and some methylbenzothiophenes were consistent with published pathways for benzothiophene biodesulfurization. Products retaining the sulfur atom were sulfones and sultines, the sultines being formed from phenolic sulfinates under acidic extraction conditions. With 2-methylbenzothiophene, the final desulfurized product was 2-methylbenzofuran, formed by dehydration of 3-(o-hydroxyphenyl) propanone under acidic extraction conditions and indicating an oxygenative desulfination reaction. With 3-methylbenzothiophene, the final desulfurized product was 2-isopropenylphenol, indicating a hydrolytic desulfination reaction. JVH1 is the first microorganism reported to use all six isomers of methylbenzothiophene, as well as some dimethylbenzothiophene isomers, as sole sulfur sources. JVH1 therefore possesses broader sulfur extraction abilities than previously reported, including not only sulfidic compounds but also some thiophenic species.

Microbial transformation of benzothiophenes, with carbazole as the auxiliary substrate, by Sphingomonas sp. strain XLDN2-5

“…These results indicate that strain XLDN2-5 is able to catalyse lateral dioxygenation and S oxidation on the thiophene ring of BT. For 2-MBT, only 2-methylbenzothiophene-1,1-dioxide was identified as a metabolite, by comparison of its mass spectrum with published data (Kirkwood et al, 2007). For 5-MBT, 5-methylbenzothiophene-5-oxide and two monohydroxy-5-methylbenzothiophenes were detected according to their mass spectra.…”

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

“…Hydrodesulfurization (HDS) is a common technology, a chemical procedure, requiring high pressure (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) and temperature (290-450°C) to reduce sulfur moiety into hydrogen sulfide [3]. At present, occasional supplementation of low sulfur-contained light crude oil and increasing demands for low sulfur-contained middle-distillated fractions, as well as considerable funds and operational expenses required to lower sulfur condensations through HDS processing, have made biodesulfurization a HDS complementary attractive technology and a cost-effective procedure for lowering the sulfur contents of petrochemicals [4,5].…”

“…Thus, DBT is generally considered as a model compound for biodesulfurization [6]. Various microorganisms have been isolated and screened as capable of cleaving C-C or C-S bonds in benzothiophene and dibenzothiophene and their alkylated derivatives [7,8]. Various strains of Rhodococcus [9][10][11], Pseudomonas [12][13][14], Bacillus [15,16], Mycobacterium [17][18][19][20], Microbacterium [21,22], Gordonia [2,9,23,24], and other genera [25,26] have been identified to have benzothiophene and/or dibenzothiophene-desulfurizing capability, most of which have been grown in enriched suspensions to characterize prosperous hydrocarbon-degrading microorganisms [7,8].…”

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

“…Desulfurization can occur in a different way depending on the substances present because the specificities of different strains differ for different sulfur compounds, and the pathway metabolism is not restricted to sulfur. This kind of desulfurization, however, comes with an associated carbon lost [158][159][160]. The sustainability of BDS depends on the selectivity of sulfur over carbon.…”