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: 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 disclosure provides an affinity polypeptide for the purification of a recombinant biologically active protein or polypeptide. Further, the present disclosure provides a fusion recombinant protein or polypeptide wherein the fusion recombinant protein comprises of at least two components, a biologically active polypeptide or protein or protein of interest and the affinity polypeptide. The biologically active polypeptide may be linked directly or indirectly to the affinity polypeptide by covalent binding. The present disclosure provides a recombinant expression vector for the producing said fusion recombinant protein in host cells. Further, the present disclosure provides an improved method of purification of recombinant protein from the host cells. Further, the disclosure provides a method of purification of the recombinant biologically active polypeptide or protein by immobilized metal ion chelating chromatography.