title: Incorporation of nisI-mediated nisin immunity improves vector-based nisin-controlled gene expression in lactic acid bacteria.
abstract: Lactic acid bacteria (LAB) have been used successfully to express a wide variety of recombinant proteins, ranging from flavor-active proteins to antibiotic peptides and oral vaccines. The nisin-controlled expression (NICE) system is the most prevalent of the systems for production of heterologous proteins in LAB. Previous optimization of the NICE system has revealed a strong limit on the concentration of the inducer nisin that can be tolerated by the culture of host cells. In this work, the nisin immunity gene, nisI, has been inserted into the recently reported pMSP3535H2 vector that contains the complete NICE system on a high-copy Escherichia coli-LAB shuttle vector. Fed-batch fermentation data show that Lactococcus lactis IL1403 cells transformed with the new vector, pMSP3535H3, tolerate a 5-fold increase in the concentration of the inducer nisin, and, at this elevated concentration, produce a 1.8-fold increased level of green fluorescent protein (GFP), a model recombinant protein. Therefore, the incorporation of nisI in the pMSP3535H3 NICE system described here unveils new ranges of induction parameters to be studied in the course of optimizing recombinant protein expression in LAB.
authors.affiliation: Department of Chemical Engineering & Materials Science, University of California, One Shields Ave, Davis, CA 95616, USA.
authors.forename: Gian M
authors.initials: GM
authors.lastname: Oddone
authors.forename: David A
authors.initials: DA
authors.lastname: Mills
authors.forename: David E
authors.initials: DE
authors.lastname: Block
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005822:Genetic Vectors / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000378:metabolism; D013294:Lactococcus lactis / Q000378:metabolism*; D008074:Lipoproteins / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009561:Nisin / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics* / Q000378:metabolism; D014169:Transformation, Bacterial
chemical_list: D001426:Bacterial Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; C094909:NisI protein, Lactococcus lactis; D011994:Recombinant Proteins; D009561:Nisin; D049452:Green Fluorescent Proteins