Isolation and characterization of glutamate dehydrogenase defective mutant of brevibacterium flavum

Brevibacterium flavum의 glutamate dehydrogenase결핍돌연변이주의 분리 및 특성

  • 최순영 (숙명여자대학교 이과대학 생물학과) ;
  • 성하진 (고려대학교 농과대학 유전공학과) ;
  • 민경희 (숙명여자대학교 이과대학 생물학과)
  • Published : 1988.06.01

Abstract

In order to understand the regulation of glutamate dehydrogenase(GDH) synthesis in Brevibacterium flavum, we have isolated a mutant lacking NADP-linked GDH activity by ethlmethane sulfonate treatment. The $gdh^-$ mutant was grown on the minimal plate with 1mM ammonium chloride and not that with 300mM ammonium chloride. The cell-free extracts from $gdh^-$ mutant and prototroph were also examined with glutamine synthetase(GS) and glutamate synthase (GOGAT) production by niteogen sources. The growth of $gdh^-$ mutant in presence of 20mM ammonium chloride means that GOGAT synthesis is sufficient to allow growth in this condition. GS production of $gdh^-$ mutant as well as parental strain was induced by 1mM urea and ammonium tartrate, but it was repressed by higher concentration of ammonia, and also induced by 20mM to 50mM glutamate as a substrate. It was special attention that GOGAT synthesis from $gdh^-$ strain was more repressed by higher concentration of ammonia than prototroph as described in E. coli system.

Keywords

Characterization of ghg-mutant;nitrogen assimilation;regulation of GDH;GS and GOGAT synthesis