In this study, atmospheric and room temperature plasma (ARTP), a promising mutation breeding technique, was successfully applied to generate Bacillus subtilis mutants that yielded large quantities of recombinant protein. The high throughput screening platform was implemented to select those mutants with the highest yield of recombinant alkaline a-amylase (AMY), including the preferred mutant B. subtilis WB600 mut-12 . The yield and productivity of recombinant AMY in B. subtilis WB600 mut-12 increased 35.0 and 8.8 , respectively, the extracellular protein concentration of which increased 37.9 . B. subtilis WB600 mut-12 exhibited good genetic stability. Cells from B. subtilis WB600 mut-12 became shorter and wider than those from the wild-type. This study is the first to report a novel powerful mutagenesis tool (ARTP) that significantly improves the yield of recombinant proteins in B. subtilis and may therefore play an important role in the high expression level of proteins in recombinant microbial hosts. ? 2015 Published by Elsevier Inc.