Growth rate related concentration changes of the starvation response regulators sigmaS and ppGpp in glucose-limited fed-batch and continuous cultures of Escherichia coli.

نویسندگان

  • A Teich
  • S Meyer
  • H Y Lin
  • L Andersson
  • S Enfors
  • P Neubauer
چکیده

The entry of Escherichia coli into glucose starvation is connected to the induction of both the stringent response and the general stress response. The concentration of the corresponding response regulators ppGpp and sigmaS (RpoS, KatF) was investigated during glucose-limited growth at different growth rates and with different cultivation strategies, including fed-batch fermentation, chemostat, and a continuous-cultivation technique with computer-controlled decrease of the feeding rate (A-stat). This study confirms the model of the in vivo effect of ppGpp on sigmaS by the direct measurement of ppGpp and sigmaS levels. The response of both regulators was clearly shown in situations where a nutrient shift occurs. A correlation in the concentration of both regulators was also shown under steady-state conditions. However, during transients with slow continuous changes of the nutrient availability, this concerted reaction of ppGpp and sigmaS is less apparent, indicating the specific importance of these regulators for the adaptation of the cells to fast changes of environmental parameters.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Physiological and Morphological Changes of Recombinant E. coli During Over-Expression of Human Interferon-g in HCDC

The objective of this research was to investigate the influence of the over-expression of recombinant interferon-g during high cell density cultivation on cellular characteristics of recombinant E. coli. Batch and fed-batch culture techniques were employed to grow Escherichia coli BL21 for production of human gamma-interferon in pET expression system. Final cell densities in batch and fed-batch...

متن کامل

Maximizing Production of Human Interferon-γ in HCDC of Recombinant E. coli

Tuning recombinant protein expression is an approach which can be successfully employed for increasing the yield of recombinant protein production in high cell density cultures. On the other hand, most of the previous results reported the optimization induction conditions during batch and continuous culture of recombinant E. coli, and consequently fed-batch culture have received less attention....

متن کامل

Maximizing Production of Human Interferon-γ in HCDC of Recombinant E. coli

Tuning recombinant protein expression is an approach which can be successfully employed for increasing the yield of recombinant protein production in high cell density cultures. On the other hand, most of the previous results reported the optimization induction conditions during batch and continuous culture of recombinant E. coli, and consequently fed-batch culture have received less attention....

متن کامل

Guanosine 3',5'-bispyrophosphate coordinates global gene expression during glucose-lactose diauxie in Escherichia coli.

Guanosine 3',5'-bispyrophosphate (ppGpp), also known as "magic spot," has been shown to bind prokaryotic RNA polymerase to down-regulate ribosome production and increase transcription of amino acid biosynthesis genes during the stringent response to amino acid starvation. Because many environmental growth perturbations cause ppGpp to accumulate, we hypothesize ppGpp to have an overarching role ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Biotechnology progress

دوره 15 1  شماره 

صفحات  -

تاریخ انتشار 1999