Simultaneous Biodetoxification of S, N, and O Pollutants by Engineering of a Carbazole-Degrading Gene Cassette in a Recombinant Biocatalyst

Abstract

The gene cassette encoding enzymes responsible for degrading carbazole to anthranilic acid was introduced into a dibenzothiophene degrader. The resultant strain, Rhodococcus erythropolis XPDN, could simultaneously transform the model pollutants dibenzothiophene, carbazole, and dibenzofuran to nontoxic metabolites and may have an application potential for bioremediation.

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

“…Bioremediation is a potential treatment alternative for eliminating these contaminants in the environment. Fundamental research has been conducted to examine the biodegradation of these hazardous compounds (Fedorak & Grbić-Galić, 1991;Boyd et al, 1993;Kropp et al, 1994a;Boyd et al, 2003;Yu et al, 2006;Safinowski et al, 2006;Gai et al, 2007;Wang et al, 2007). However, it remains unclear whether benzothiophenes have an inhibitory effect on N-heterocyclic compounds such as CA, although other studies have shown that S-, N-and O-heterocyclic aromatic compounds can have a significant inhibitory effect on the biodegradation of polycyclic aromatic hydrocarbons (Dyreborg et al, 1996a(Dyreborg et al, , b, 1997Meyer & Steinhart, 2000).…”

Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads

“…Our laboratory has also isolated and constructed several bacteria that can degrade these heterocyclic compounds (6,18,19,20,43,44). The isolates degrade carbazole by following similar pathways, in which carbazole is initially attacked at the angular position by dioxygenation, followed by spontaneous conversion of the dihydroxylated intermediate to 2Ј-aminobiphenyl-2,3-diol.…”

Genome Sequence of Rhodococcus erythropolis XP, a Biodesulfurizing Bacterium with Industrial Potential

“…R. erythropolis XP is a strain isolated from soils and has been proved efficient in deep desulfurization of petroleum oils, including gasoline, diesel, and crude oil, through the 4S pathway (10,12). Strain XP was also successfully used as a host for developing a recombinant biocatalyst for biodetoxification of S/N/O pollutants (11). Therefore, strain XP was considered to be potentially one of the best strains for use in industrial desulfurization (5).…”