Saturday, 23rd June 2018

Virology and Microbiology

                   Biotechnology and genetics of extreme thermophilic bacteria





José Berenguer Carlos




Research summary:

In our laboratory we study i) the anaerobic metabolism of extreme thermophilic bacteria, ii) the lateral gene transfer (LGT) of the corresponding genes, and iii) we develop biotechnological applications derived from their use or from that of their enzymes. As main lab model we use the extreme thermophilic bacterium Thermus thermophilus (Tth) for being exceptionally easy to growth and manipulate compared to most extreme thermophiles. Its ancient phylogeny and the thermal stability of its cellular components and complexes make of Tth one of the favorite models for both, Evolutionary and Structural Biology programs.
In the last two years we have focused on the analysis of the enzymes involved in the final steps of denitrification. We characterized the nitrite and the nitric oxide reductases, encoded within a gene cluster susceptible of LGT, but whose expression depends on the nitrate respiration gene cluster. Regarding the LGT mechanisms of the denitrification genes, we have identified a cell-to-cell transfer that involves no homologues to proteins from classical conjugation systems. We have also started the studies on the barriers that protect Tth from invading DNA, especially on those that involve nucleic acid-based interference mechanisms.

   Themostable color variants of fluorescent proteins expressed at 70ºC in Thermus thermophilus. Images correspond to merging of fluorescence and phase contrast channels  

In more applied grounds, our efforts have focused mainly on two aspects. On one side, we have selected thermostable variants of proteins using either folding interference techniques in Tth (i.e. Pseudomonas fluorescens esterase I) or rational design (i.e. thermostable fluorescent proteins). In addition, we have overexpressed, purified and characterized highly thermostable enzymes of biotechnological interest, such as a penicillin acylase or nucleoside phosphorylases.
In the next years we will continue our studies on the mechanisms of LGT and its barriers, and will start a large-scale project aimed to the identification and isolation in vitro of thermostable enzymes through a recently developed new signal generation system.

Selected Publications:

  • Alvarez L., Bricio C., Gómez, M. J., and Berenguer, J. (2011) Lateral transfer of the denitrification pathway among Thermus thermophilus strains. Appl Env. Microbiol 77, 1352-1358.
  • Alvarez, L., Bricio, C., Chahlafi, Z., Cava,F., Hidalgo, A., and Berenguer, J. (2011) Regulación y transferencia horizontal de la desnitrificación en Thermus sp In I.S.B.N. 978-84-8454-806-5. Universidad de Córdoba, Córdoba, Spain, pp. 173-186
  • Bolivar, J. M., Hidalgo, A., Sánchez-Ruiloba, L., Berenguer, J., Guisán, J. M., and López-Gallego, F. (2011).J. Biotech 155, 412-420
  • Bricio, C., Alvarez, L., Gómez, M. J., and Berenguer J. (2011) Partial and complete denitrification in Thermus thermophilus: lessons from genome drafts. Biochem Soc Trans 39:249-253.
  • César, C. E., Alvarez, L., Bricio, C., van Heerden, E., Littauer D. and Berenguer J. (2011) Unconventional lateral gene transfer in extreme thermophilic bacteria. Int Microbiol 14,187-199.

Last Doctoral Theses:

Carlos Bricio Garberí (2012) Reducción de óxidos de nitrógeno gaseosos en Thermus thermophilus. Universidad Autónoma de Madrid (mención europea). Director: José Berenguer   

Laura Alvarez Muñoz (2012) Análisis de la respiración de nitrito en Thermus thermophilus. Universidad Autónoma de Madrid(mención europea). Director: José Berenguer

Zahra Chahlafi (2012) Caracterización de la regulación por nitrato en la respiración anaeróbica de Thermus thermophilus. Universidad Autónoma de Madrid. Director: José Berenguer      

Marcos Almendros Giménez (2011) Nuevas enzimas termoestables aplicadas a la síntesis de nucleósidos farmacológicamente activos. Universidad Autónoma de Madrid. Directores: José Berenguer y Josep Vicent Sinisterra    

Federico Acosta Castro (2011) Incorporación de subunidades y crecimiento de la capa S de Thermus thermophilus. Universidad Autónoma de Madrid. Director: José Berenguer  

Eloy Roberto Ferreras Puente (2011) Expresión y estudio de enzimas termoestables de interés biotecnológico. Universidad Autónoma de Madrid. Director: José Berenguer        


-Torres, L. L., Hidalgo, A., Ferreras, E. R., Berenguer, J. "Polipéptido termoestable con actividad penicilina acilasa, variantes del mismo y sus aplicaciones". Número de prioridad: P201230729. País de prioridad: España. Fecha de prioridad: 14-05-2012     

-Hidalgo, A., Rivera, N, Sánchez, E., Berenguer J. “Polipéptido termoestable con actividad esterasa, variantes del mismo y sus aplicaciones” Número de solicitud: P201231439.  país de prioridad: España. Fecha de prioridad: 17-09-2012