Bacillus subtilis has become an increasingly popular host for recombinant protein expression. With its ability to secrete protein directly into culture media, amenability to medium- and large-scale fermentation, lack of codon bias, and designation by the U.S. Food and Drug Administration as an organism that is Generally Regarded As Safe (GRAS), it"s no wonder that the majority of industrially-produced enzymes are expressed in Bacillus species such as B. subtilis. Optimization of secretion, however,may berequired to achieveoptimal yield. To address this concern, the B. Subtilis Secretory Protein Expression System from Takara Bio allows rapid development of a B. subtilis clone library, with each clonebearing a pBE-S construct in which the ORFof your protein of interest is fused with 173 different sequences for unique signal peptides. By performing a downstream assay to identify and select the clonethat secretes the highest amount of functional protein, you can quickly identifywhich signal peptide results in the mostefficient expression of your desired secreted protein.