Open AccessDesulfurization of alkylated forms of both dibenzothiophene and benzothiophene by a single bacterial strain
Author(s) -
Kobayashi Morio,
Onaka Toshimitsu,
Ishii Yoshitaka,
Konishi Jin,
Takaki Mikihiro,
Okada Hideki,
Ohta Yoshinori,
Koizumi Kenichi,
Suzuki Masanori
Publication year - 2000
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2000.tb09147.x
Subject(s) - dibenzothiophene , benzothiophene , chemistry , rhodococcus , rhodococcus rhodochrous , monooxygenase , organic chemistry , bond cleavage , sulfone , biocatalysis , sulfur , stereochemistry , thiophene , enzyme , reaction mechanism , cytochrome p450 , catalysis
Thirty‐five bacterial strains capable of converting dibenzothiophene into 2‐hydroxybiphenyl were isolated. Among them Rhodococcus erythropolis KA2‐5‐1 was chosen for further characterization because of its ability to retain high desulfurization activity stably. PCR cloning and DNA sequencing of a KA2‐5‐1 genomic DNA fragment showed that it was practically identical with dszABC genes from Rhodococcus sp. IGTS8, a representative carbon–sulfur‐bond‐targeted dibenzothiophene‐degrading bacterium. KA2‐5‐1 desulfurized a variety of alkyl dibenzothiophenes through the specific cleavage of their C–S bonds. In addition, unexpectedly, KA2‐5‐1 also attacked alkyl benzothiophenes in a C–S‐bond‐targeted fashion. The purified monooxygenase, encoded by dszC of KA2‐5‐1, converted benzothiophene and dibenzothiophene into benzothiophene sulfone and dibenzothiophene sulfone, respectively, with the aid of an NADH‐dependent oxidoreductase. This result raises the possibility that the same enzymatic step may be involved in desulfurization of alkylated forms of both dibenzothiophene and benzothiophene in KA2‐5‐1 cells.