title: A novel salt-inducible vector for efficient expression and secretion of heterologous proteins in Bacillus subtilis.
abstract: Bacillus subtilis is commonly used as a host for heterologous protein production via plasmid-based expression system. In order to improve product safety, avoid carbon catabolite repression and lower production cost, a novel salt-inducible vector, pSaltExSePR5, was developed based on a natural plasmid of Lactobacillus plantarum BCC9546. Salt-inducible promoter opuAA and a DNA fragment encoding a signal peptide of subtilisin E (SubE) were sequentially added to the core shuttle vector to facilitate expression and secretion of a target protein in B. subtilis. To evaluate the effectiveness of this system under salt induction, a protease gene from Halobacillus sp. without its native signal sequence was inserted in the pSaltExSePR5 plasmid downstream of SubE signal sequence and transformed into B. subtilis WB800. Protease activities from cell-free supernatants of the recombinant bacteria cultures induced with 0.5-6% NaCl were analyzed. The highest protease activity of 9.1 U/ml was obtained after induction with 4% NaCl, while the non-induced culture exhibited activity of 0.128 U/ml. The results demonstrated that pSaltExSePR5 provides an alternative vector for efficient and simple production of heterologous proteins in B. subtilis with a safer and more economic inducer.
authors.affiliation: Microbial Cell Factory Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Ruangurai
authors.initials: R
authors.lastname: Promchai
authors.affiliation: Biocontrol Research Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Boonhiang
authors.initials: B
authors.lastname: Promdonkoy
authors.affiliation: Microbial Cell Factory Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Sutipa
authors.initials: S
authors.lastname: Tanapongpipat
authors.affiliation: Food Biotechnology Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Wonnop
authors.initials: W
authors.lastname: Visessanguan
authors.affiliation: Bioresources Research Unit, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand.
authors.forename: Lily
authors.initials: L
authors.lastname: Eurwilaichitr
authors.affiliation: Microbial Cell Factory Laboratory, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113, Thailand Science Park, Phahonyothin Road, Klong 1, Klong Luang, Pathumthani 12120, Thailand. Electronic address: plearn@biotec.or.th.
authors.forename: Plearnpis
authors.initials: P
authors.lastname: Luxananil
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism; D001622:Betaine / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D005822:Genetic Vectors / Q000235:genetics*; D010957:Plasmids / Q000235:genetics*; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D011994:Recombinant Proteins; D001622:Betaine; D012965:Sodium Chloride
keywords: Bacillus subtilis; Expression and secretion vector; Heterologous protein production; Salt-inducible promoter