Abstract: The present invention discloses a process for the preparation of rhPTH (1-34) also known as teriparatide by construction of a novel nucleotide, as an NcoI.IXhoI fragment as set forth in SEQ. ID. No.:1 encoding a chimeric fusion protein as set forth in SEQ.ID. No.:2 comprising of a fusion partner consisting of 41 amino acids belonging to Escherichia coli ?-galactosidase (LacZ) gene, an endopeptidase cleavage site, rhPTH (1-34) gene fragment, cloning the said nucleotide in an expression vector under the control of T7 promoter, transforming Escherichia coli with the said vector and expressing the chimeric fusion protein in fed batch fermentation. The present invention further discloses a low feed rate lactose induction for optimized expression of rhPTH (1-34) in Escherichia coli.

Abstract: A low cell density fermentation process for the production of heterologous proteins in microorganisms. The cell culture obtained by cultivating host microorganisms transformed with a vector carrying genetic material for the said proteins and an inducible promoter under batch fermentation conditions is fed with a feed medium after an OD600 of 0.16 to 8 has been achieved or after 0 to 4 hrs from the start of the fermentation process. The feed medium comprises 5 to 30% of carbon source and 1 to 30% of nitrogen source and 0 mg to 400 mg antibiotics and 2.5 to 4.25% inorganic phosphates and trace elements. The concentration of the carbon source in the feed medium is 10 to 30 and the amino acid content in nitrogen source is 45 to 95%. The initial feed rate is in the range of 0 ml/hr to 12 ml/hr and is raised exponentially by an exponent in the range of 0.1 to 0.4 and/or linearly with the slope of the curve in the range of 0.5 to 3. The production of the heterologous proteins is induced with 0.

Abstract: The present invention discloses a process for the preparation of rhPTH (1-34) also known as teriparatide by con-struction of a novel nucleotide, as an NcoI.IXhoI fragemt as set forth in SEQ. ID. No.:1 encoding a chimeric fusion protein as set forth in SEQ.ID. No.:2 comprising of a fusion partner consisting of 41 amino acids belonging to Escherichia coli ?-galactosidase (LacZ) gene, an endopeptidase cleavage site, rhPTH (1-34) gene fragment, cloning the said nucleotide in an expression vector under the control of T7 promoter, transforming Escherichia coli with the said vector and expressing the chimeric fusion protein in fed batch fermentation. The present invention further discloses a low feed rate lactose induction for optimized expression of rhPTH (1-34) in Escherichia coli.

Abstract: A low cell density fermentation process for the production of heterologous proteins in microorganisms. The cell culture obtained by cultivating host microorganisms transformed with a vector carrying genetic material for the said proteins and an inducible promoter under batch fermentation conditions is fed with a feed medium after an OD600 of 0.16 to 8 has been achieved or after 0 to 4 hrs from the start of the fermentation process. The feed medium comprises 5 to 30% of carbon source and 1 to 30% of nitrogen source and 0 mg to 400 mg antibiotics and 2.5 to 4.25% inorganic phosphates and trace elements. The concentration of the carbon source in the feed medium is 10 to 30 and the amino acid content in nitrogen source is 45 to 95%. The initial feed rate is in the range of 0 ml/hr to 12 ml/hr and is raised exponentially by an exponent in the range of 0.1 to 0.4 and/or linearly with the slope of the curve in the range of 0.5 to 3. The production of the heterologous proteins is induced with 0.