Augusto Rojas-Aparicio, José A. Hernández-Eligio, Jeiry Toribio-Jiménez, Miguel Á. Rodríguez-Barrera, Mildred Castellanos-Escamilla, Yanet Romero-Ramírez
Published: April 27, 2018
Genet. Mol. Res. 17(2): gmr16039916
DOI: https://doi.org/10.4238/gmr16039916
Cite this Article:
A. Rojas-Aparicio, J.A. Hernández-Eligio, J. Toribio-Jiménez, M.Á. Rodríguez-Barrera, M. Castellanos-Escamilla, Y. Romero-Ramírez (2018). Genetic expression of pobA and fabHB in Bacillus licheniformis M2-7 in the presence of benzo[a]pyrene. Genet. Mol. Res. 17(2): gmr16039916. https://doi.org/10.4238/gmr16039916
About the Authors
Augusto Rojas-Aparicio, José A. Hernández-Eligio, Jeiry Toribio-Jiménez, Miguel Á. Rodríguez-Barrera, Mildred Castellanos-Escamilla, Yanet Romero-Ramírez
Corresponding Author
Yanet Romero Ramírez
Email:yromero@uagro.mx
ABSTRACT
Bacillus licheniformis M2-7 is a heat-resistant bacterium able to biotransform polycyclic aromatic hydrocarbons. It can transform a wide range of these compounds as naphthalene, phenanthrene, pyrene and benzo[a]pyrene. Benzo[a]pyrene is a polycyclic aromatic hydrocarbon of high molecular weight considered as potentially toxic and carcinogenic for humans. Aiming to discover the genes involved in the biotransformation of benzo[a]pyrene, we made a B. licheniformis M2-7 genomic library in E. coli. We isolated two E. coli strains that were able to grow in minimal salt medium supplemented with benzo[a]pyrene. From the analysis of the DNA fragments in the clones H23 and H38, we identified open reading frames coding for 5 possible genes, among them pobA and fabHB, which products are the enzymes 4-hydroxybenzoate 3-monooxygenase and the ketoacyl-ACP synthase III, respectively. To evaluate the role of these genes in the metabolism of benzo[a]pyrene in B. licheniformis M2-7, we estimated their relative expression through reverse transcription quantitative PCR. Finally, we observed that the genes pobA and fabHB were overexpressed after 3 h under induction with benzo[a]pyrene, suggesting that this strain could use these genes during the metabolism of this PAH, plus it does it in a faster time than that reported for other bacterial genera
Key words: 4-hydroxybenzoate 3-monooxygenase (pobA), Bacillus licheniformis M2-7, benzo[a]pyrene, KetoacylACP synthase III (fabHB), Reverse transcription quantitative (PCR).