De-repression and comparison of oil–water separation activity of the dibenzothiophene desulfurizing bacterium, Mycobacterium sp. G3

Abstract

Expression of the desulfurization genes (dsz) in Mycobacterium sp. G3 is repressed by sulfate, which is the product of biodesulfurization. An expression clone, pSMTABC, was constructed by placing the dsz genes downstream of the hsp60 promoter and the constructed plasmid was electroporated into G3. The recombinant strain G3-1 desulfurized dibenzothiophene in the presence of 0.5 mM: sulfate while the Dsz phenotype was completely repressed in the wild-type strain. However, there was no significant increase in the amount of desulfurization enzymes in G3-1. In addition, G3 had superior separation of diesel oil-water separation activity compared to E. coli, which is superior to desulfurizing rhodococci.

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

“…In this sense, an important research line goes to the development of more resistant and efficiency biocatalyst that can work in biphasic reaction media. (Takada et al 2005;Tao et al 2006). On the other hand, the problem of low solubility of the aromatic sulfur compounds in the aqueous fraction of media was studied as is reported by Feng et al (2006).…”

Biodegradation of dibenzothiophene and its application in the production of clean coal

“…Analogous studies with Mycobacterium sp.G3 have revealed the functional expression of dsz ABC genes in recombinant E. coli JM109 [34]. Takada et al [106] showed that Mycobacterium sp. G3 with an inserted pSMT ABC fragment containing the dsz genes downstream of the hsp60 promoter could function unrepressed in the presence of 0.5 mM sulphate per liter.…”

A Review on Desulfurization Techniques of Liquid Fuels

“…[17]. The biodesulfurization process carried out in two phase system, whether whole cell used as biocatalyst in the aqueous phase interacts with oil phase [4,33]. Long ago only gram positive bacteria utilized for biodesulfurization of sulfur compounds.…”

“…the desulfurization via microorganism of refractory sulfur compounds achieve to 1000-100 mg/dm 3 in 24h [36]. Fatemeh et al [33] applied Rhodococcus erythropolis (SHT87) strain which was isolated from oil contaminated soils in Iran for biodesulfurization of organosulfur compounds. Rhodococcus erythropolis(SHT87) was found to three sulfur metabolizing genes such as DszA, DszB, DszC, which indicates that SHT87 strain converts dibenzothiophene to 2-hydroxybiphenyl(2-HBP) through 4S pathway.…”