Advances of Efficient Secretory Expression for Heterologous Proteins from Bacillus Species

Secreted proteins are easily to be purified and acquired a large amount with low cost,thus secretory expression of the target gene is an ideal expression model for the heterologous proteins. Bacillus expression system is one of the excellent heterologous protein expression systems,as most of the Bacillus species have the capability to secrete the target protein. So far,a large number of genes from different species have been cloned and achieved efficently secretory expression in Bacillus species.Many proteins even obtained very high yields. However,the protein secretory system of Bacillus still has many defects. The low yield for some proteins extremely limits its use as major cell factoriesin the biological field. Here we summarized the limiting factors for the secretion of the target protein and also provided some solutions for such problems.