Abstract:
One of the greatest challenges in the production of recombinant proteins with high cells concentrations using the bacteria Escherichia coli as host is the accumulation of acetate, harmful to cell growth. Acetic acid can be produced when bacteria Escherichia coli is grown in anaerobic conditions, oxygen-limiting or through the catabolic repression. This work aims at monitoring the formation of acetic acid through the estimate of the specific cell growth rate from the specific respiration microbial rate in real time. For this, the dissolved oxygen concentration in the reactor (% pO2) was kept constant and above the critical concentration value of 0.26 mg/L. Another strategy used was to limit the carbon source, avoiding catabolic repression. The oxygen uptake rate was calculated from the values of % O2 (v/v) measured by a gas analyzer in real-time and related to the speed of the formation of acetic acid. This online monitoring allowed the identification of the formation of acetic acid in the medium and made it possible to change the flow of carbon source, in order to prevent the formation of acetic acid and consequently avoid the inhibition by this product, resulting in high cell concentrations.
Reference:
MELLO, Caroline Matos de; MARTELETO, Natalia Bonifacio; MARQUES, Telma de Oliveira; OLIVEIRA, Valter; RODRIGUES, Maria Filomena de Andrade; PICCOLI, Rosane Aparecida Moniz. Acetic acid formation in Escherichia coli cultivation using the oxygen uptake rate as response. In: SIMPÓSIO NACIONAL DE BIOPROCESSOS, 21., SIMPÓSIO DE HIDRÓLISE ENZIMÁTICA DE BIOMASA, 12., 2017, Aracaju. Anais… 5 p.
Document with restricted access. Log in to BiblioInfo Biblioteca-DAIT/IPT to access the PDF text:
https://escriba.ipt.br/pdf_restrito/174809.pdf
One of the greatest challenges in the production of recombinant proteins with high cells concentrations using the bacteria Escherichia coli as host is the accumulation of acetate, harmful to cell growth. Acetic acid can be produced when bacteria Escherichia coli is grown in anaerobic conditions, oxygen-limiting or through the catabolic repression. This work aims at monitoring the formation of acetic acid through the estimate of the specific cell growth rate from the specific respiration microbial rate in real time. For this, the dissolved oxygen concentration in the reactor (% pO2) was kept constant and above the critical concentration value of 0.26 mg/L. Another strategy used was to limit the carbon source, avoiding catabolic repression. The oxygen uptake rate was calculated from the values of % O2 (v/v) measured by a gas analyzer in real-time and related to the speed of the formation of acetic acid. This online monitoring allowed the identification of the formation of acetic acid in the medium and made it possible to change the flow of carbon source, in order to prevent the formation of acetic acid and consequently avoid the inhibition by this product, resulting in high cell concentrations.
Reference:
MELLO, Caroline Matos de; MARTELETO, Natalia Bonifacio; MARQUES, Telma de Oliveira; OLIVEIRA, Valter; RODRIGUES, Maria Filomena de Andrade; PICCOLI, Rosane Aparecida Moniz. Acetic acid formation in Escherichia coli cultivation using the oxygen uptake rate as response. In: SIMPÓSIO NACIONAL DE BIOPROCESSOS, 21., SIMPÓSIO DE HIDRÓLISE ENZIMÁTICA DE BIOMASA, 12., 2017, Aracaju. Anais… 5 p.
Document with restricted access. Log in to BiblioInfo Biblioteca-DAIT/IPT to access the PDF text:
https://escriba.ipt.br/pdf_restrito/174809.pdf
