Screening of Heterologous Signal Peptides for Optimization of the LIKE-Expression System

Abstract

© 2016, Springer Science+Business Media New York.The LIKE-expression system was optimized and used for the production of serine proteinases: subtilisin-like proteinase (AprBp) and glutamyl endopeptidase (GseBp) from Bacillus pumilus. Genes of these enzymes were amplified from genomic DNA of the B. pumilus strain 3-19 and cloned into the LIKE-expression system under the control of the PliaI antibiotic-inducible promoter. Two parameters were investigated to increase the yield of secretory enzymes: heterologous signal peptides from B. megaterium (SPPac, SPYngk) and B. subtilis host strain, which is deficient in two major extracellular proteinases (nprE, aprE). Increased production of GseBp with recombinant SPYngk was achieved after 12 h of growth while increased production of AprBp with its own signal peptide after adding bacitracin was achieved after 20 h of growth. These results suggest that optimized LIKE-expression system can be used for heterologous secretory protein production in B. subtilis.