Metabolic characterization and genes for the conversion of biphenyl in Dyella ginsengisoli LA-4.

A complete bph gene cluster (bphLA-4) containing 12,186 bp was amplified from Dyella ginsengisoli LA-4. The bphLA-4 was composed of bphABCXD, and an additional gene encoding a meta-fission product hydrolase was located in the bphX region. BphLA-4 was independently transcribed by the two operons, bphA1A2orf1A3A4BCX0 and bphX1orf2X2X3D, and significantly differed from bphKF707. Both benzoate and catechol induced the expression of both operons. 2-Hydroxypenta-2,4-dienoate was identified as the intermediate of the biphenyl degradation by strain LA-4. This finding suggested that there existed a novel lower pathway of biphenyl degradation in strain LA-4.