Modares Journal of Biotechnology

Abstract Aims: Peroxidases are used in a wide range of biotechnological processes, most of which are carried out at high temperatures and high pH levels. Since most of the commonly used peroxidases are unstable and inactive in alkaline conditions and high temprature, it is necessary to find thermoalkalophilic peroxidases for practical purposes.
Materials and Methods: In this study, extracellular production of peroxidase in the native strain Bacillus tequilensis was studied. for this purpose, Enzyme activity was evaluated using two substrates 2,4-DCP and pyrogallol in bacterial liquid culture and the effect of culture time on enzyme production, as well as the effect of parameters such as pH and temperature on enzyme activity investigated. The relative purification of the enzyme was performed using ion exchange chromatography with sephadex DEAE A50 and the kinetic parameters of enzyme activity were evaluated. In this study, kinetic parameters such as Km and Vmax were calculated.
Results: Measurement of enzyme activity at different times of culture indicated that the highest amount of peroxidase production was obtained 72 h after bacterial culture.

Abstract Introduction: Growth hormone is a non-glycosylated polypeptide strand of the pituitary glands of all vertebrates that has a wide range of biological activities and considering the importance of this hormone and its importance and diverse therapeutic applications in medicine, its recombinant production can be of great importance. In recent decades, protein engineering and genetic engineering have resulted in a high level of expression and production of this protein in a variety of hosts, including Escherichia coli bacteria using new techniques and methodes, hormone purification and assay are carried out easily. Therefore, the aim of this review was to investigate the production of recombinant human growth hormone (rhGH) and future challenges.
Conclusion: One of the problems of the expression and purification of the human growth hormone may involve that maybe noted the production of inclusion bodies in the expression of recombinant proteins in the cell cytoplasm, the contamination caused by host proteins, low protein recovery from these inclusion bodies, low protein secretion into the Periplasmic space, high cost of production, especially in Purification stage and so on. Due to the lack of need for glycosylated hormone and high efficiency and simplicity of work, bacterial systems, especially Escherichia coli, are the most economical and effective systems for the expression of heterologous proteins. The hormone purification stage is usually the most costly process. Therefore, an optimal design for achieving the highest target protein recovery with the elimination of all contamination from the final product and reducing the purification step is required.