Evidence of an association between poly(3-hydroxybutyrate) accumulation and phosphotransbutyrylase expression in Bacillus megaterium

Authors

  • Gustavo J. Vázquez Gustavo J. Vázquez Departamento de Química Biológica, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
  • M. Julia Pettinari Departamento de Química Biológica, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina
  • Beatriz S. Méndez Departamento de Química Biológica, Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Buenos Aires, Argentina

Keywords:

Bacillus megaterium, polyhydroxybutyrate, phosphotransbutyrylase

Abstract

Molecular analysis of a genomic region of Bacillus megaterium, a polyhydroxybutyrate (PHB)- producing microorganism, revealed the presence of a gene coding for the enzyme phosphotransbutyrylase (Ptb). Enzyme activity was measured throughout the different growth phases of B. megaterium and was found to correlate with PHB accumulation during the late-exponential growth phase. Ptb expression was repressed by glucose and activated by the branched amino acids isoleucine and valine. Overexpression of ActBm, a σ 54 regulator from B. megaterium whose gene is located upstream from ptb, caused an increase in Ptb activity and PHB accumulation in B. megaterium.

Downloads

Published

2010-03-08

Issue

Section

Research Articles