Verification of knockout of mbnT in M. trichosporium by PCR. M, molecular weight markers; lane 1, PCR of mbnT from the M. trichosporium OB3b mbnT::Gmr mutant; lane 2, PCR of mbnT from wild-type M. trichosporium OB3b; lane 3, PCR of pK18mobsacB backbone in M. trichosporium OB3b mbnT::Gmr; lane 4, PCR of pK18mobsacB backbone in pWG011.