Iraninan Biology Society Journal of Cellular and Molecular Research (Iranian Journal of Biology) 2383-2738 Articles in Press 2026 02 15 Investigation of secreted human fibroblast growth factor (hbFGF) production in the Bacillus subtilis Investigation of secreted human fibroblast growth factor (hbFGF) production in the Bacillus subtilis 2506 10.22034/cmr.2026.8577.3314 FA سارا طالع احمد Faculty member of Royan Institute 0000-0003-4666-1907 Hanieh Jadid University of Science and Culture Esmaeil Jarahi Royan Institute Samira Shakeri Royan Institute Hedie Poorkazem Royan Institute Journal Article 2025 01 07 The production of recombinant proteins is a vital advanced technology in biotechnology that plays a crucial role in life sciences and medicine. Growth factors, such as the basic fibroblast growth factor (bFGF), are of paramount importance in the development of innovative therapies and the enhancement of patients' quality of life due to their key roles in wound healing and cell proliferation. This study aims to produce human recombinant fibroblast growth factor (hbFGF) in the Bacillus subtilis strain, providing an efficient and cost-effective method for producing this vital protein. Bacillus as a host is capable of the secretion of recombinant proteins, enhancing the efficiency and quality of the product while reducing production costs. In this research, the hbFGF gene was initially cloned into the PHT-43 vector, which was then transformed into E. coli Following this, a secondary transformation was performed into Bacillus subtilis. Subsequently, the processes of expression, extraction, and purification of the protein were carried out. Finally, its biological activity was evaluated using assays on the NIH/3T3 cell line. The results demonstrated the successful expression and secretion of hbFGF protein in the Bacillus subtilis strain; however, the quantity of purified protein was not optimal compared to the nickel-column bound protein. Analyses indicated that various proteases in Bacillus subtilis contributed to the cleavage of part of the protein before the His-tag sequence, leading to a decrease in the purity of the final product. To address this issue, it is recommended to utilize engineered strains with greater efficiency that contain protease inhibitors, preventing the cleavage of the produced protein. The production of recombinant proteins is a vital advanced technology in biotechnology that plays a crucial role in life sciences and medicine. Growth factors, such as the basic fibroblast growth factor (bFGF), are of paramount importance in the development of innovative therapies and the enhancement of patients' quality of life due to their key roles in wound healing and cell proliferation. This study aims to produce human recombinant fibroblast growth factor (hbFGF) in the Bacillus subtilis strain, providing an efficient and cost-effective method for producing this vital protein. Bacillus as a host is capable of the secretion of recombinant proteins, enhancing the efficiency and quality of the product while reducing production costs. In this research, the hbFGF gene was initially cloned into the PHT-43 vector, which was then transformed into E. coli Following this, a secondary transformation was performed into Bacillus subtilis. Subsequently, the processes of expression, extraction, and purification of the protein were carried out. Finally, its biological activity was evaluated using assays on the NIH/3T3 cell line. The results demonstrated the successful expression and secretion of hbFGF protein in the Bacillus subtilis strain; however, the quantity of purified protein was not optimal compared to the nickel-column bound protein. Analyses indicated that various proteases in Bacillus subtilis contributed to the cleavage of part of the protein before the His-tag sequence, leading to a decrease in the purity of the final product. To address this issue, it is recommended to utilize engineered strains with greater efficiency that contain protease inhibitors, preventing the cleavage of the produced protein.