Evaluation of induction conditions for plasmid pQE-30 stability and 503 antigen of Leishmania i. chagasi expression in E. coli M15

• Published in: Applied microbiology and biotechnology Vol. 103; no. 16; pp. 6495 - 6504
• Main Authors: Ribeiro, Vitor Troccoli, Asevedo, Estéfani Alves, de Paiva Vasconcelos, Luan Tales Costa, Filho, Marcos Antônio Oliveira, de Araújo, Jaciara Silva, de Macedo, Gorete Ribeiro, de Sousa Júnior, Francisco Canindé, dos Santos, Everaldo Silvino
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.08.2019; Springer; Springer Nature B.V
• Subjects: Analysis; Antigens; Antigens, Protozoan - biosynthesis; Antigens, Protozoan - genetics; Bacteria; Biomedical and Life Sciences; Biotechnological Products and Process Engineering; Biotechnology; Cell culture; E coli; Escherichia coli; Escherichia coli - genetics; Escherichia coli - metabolism; Gene Expression; Genomic Instability - drug effects; Isopropyl Thiogalactoside - metabolism; Leishmania; Leishmania - genetics; Life Sciences; Metabolism; Microbial Genetics and Genomics; Microbiology; Plasmids; Recombinant proteins; Recombinant Proteins - biosynthesis; Recombinant Proteins - genetics; Stability; Stability analysis; Temperature; Toxicity; Transcriptional Activation; Brazil; Induction; Plasmid stability; 503 antigen; Leishmania i. chagasi
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-019-09948-z

The present study aimed to evaluate the influence of induction conditions (IPTG concentration, temperature, and induction time) on the plasmid pQE-30 stability and 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15. Batch cultures were performed at 37 °C and induced by the addition of different IPTG concentrations (0.01 to 1.5 mM). Subsequently, experiments were carried out at different temperatures (27 to 42 °C), evaluating the influence of induction time (0.5 to 6 h after the start of the culture). The results showed that IPTG toxicity caused a metabolic stress in the cells and, consequently, the microorganism growth reduced. The induction with IPTG may also be associated with the plasmid pQE-30 instability, due to metabolic burden imposed by the recombinant protein expression. The optimal conditions for 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15 were an IPTG concentration of 1.0 mM, temperature of 37 °C, and induction time of 2 h. The maximum antigen concentration obtained was 0.119 ± 0.009 g/L, about seven times higher than the lowest concentration. Therefore, the results showed that 503 antigen can be produced in laboratory; however, it requires more studies to minimize the plasmid instability and improve to industrial scale.