%0 Journal Article %A Mukerjee-Dhar, Gouri %A Shimura, Minoru %A Miyazawa, Daisuke %A Kimbara, Kazuhide %A Hatta, Takashi %T bph genes of the thermophilic PCB degrader, Bacillus sp. JF8: characterization of the divergent ring-hydroxylating dioxygenase and hydrolase genes upstream of the Mn-dependent BphC %D 2005 %J Microbiology, %V 151 %N 12 %P 4139-4151 %@ 1465-2080 %R https://doi.org/10.1099/mic.0.28437-0 %K HMSA, 2-hydroxymuconic semialdehyde %K HOHDA, 2-hydroxy-6-oxohepta-2,4-dienoic acid %K 6-phenyl HODA, 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid %K PCB, polychlorinated biphenyl %I Microbiology Society, %X Bacillus sp. JF8 is a thermophilic polychlorinated biphenyl (PCB) degrader, which utilizes biphenyl and naphthalene. A thermostable, Mn-dependent 2,3-dihydroxybiphenyl 1,2-dioxygenase, BphC_JF8, has been characterized previously. Upstream of bphC are five ORFs exhibiting low homology with, and a different gene order from, previously characterized bph genes. From the 5′ to 3′ direction the genes are: a putative regulatory gene (bphR), a hydrolase (bphD), the large and small subunits of a ring-hydroxylating dioxygenase (bphA1A2), and a cis-diol dehydrogenase (bphB). Hybridization studies indicate that the genes are located on a plasmid. Ring-hydroxylating activity of recombinant BphA1A2_JF8 towards biphenyl, PCB, naphthalene and benzene was observed in Escherichia coli cells, with complementation of non-specific ferredoxin and ferredoxin reductase by host cell proteins. PCB degradation by recombinant BphA1A2_JF8 showed that the congener specificity of the recombinant enzyme was similar to Bacillus sp. JF8. BphD_JF8, with an optimum temperature of 85 °C, exhibited a narrow substrate preference for 2-hydroxy-6-oxo-6-phenylhexa-2,4-dienoic acid. The Arrhenius plot of BphD_JF8 was biphasic, with two characteristic energies of activation and a break point at 47 °C. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.28437-0