Catalyzes the third and final step of the '4S' desulfurization pathway that removes covalently bound sulfur from dibenzothiophene (DBT) without breaking carbon-carbon bonds. Oxidizes 2-(2'-hydroxyphenyl)benzene sulphinate (HBPS) to 2-hydroxybiphenyl (HBP) plus sulfite. The rate-limiting step of the '4S' desulfurization pathway. 2'-hydroxybiphenyl-2-sulfinate + H2O = biphenyl-2-ol + H(+) + sulfite Sulfur metabolism; dibenzothiophene degradation. Monomer. Repressed by HBP or sulfate (Probable). Part of the dszA-dszB-dszC operon. This protein is expressed at quite low levels in R.erythropolis (at protein level) (PubMed:17420595). Expression in B.subtilis confers the ability to remove sulfur from polycyclic aromatic sulfur compounds found in gasoline and diesel (biodesulfurization), which are a considerable source of pollution (PubMed:16810451). Modification of the operon so the start codon of dszB no longer overlaps with the stop codon of dszA leads to increased expression of DszB (in R.erythropolis) and about 5-fold higher levels of desulfurization of DBT (PubMed:17420595). Rearrangement of the operon into the order dszB-dszC-dszA leads to 12-fold higher levels of DBT desulfurization (PubMed:18165370). Belongs to the DszB desulfinase family.