Development of a split-luciferase assay to establish optimal protein secretion conditions for protein production by .

is a Gram-positive bacterium that is frequently used in the bioindustry for the production of various proteins, because of its superior protein secretion capacities. To determine optimal conditions for protein secretion by , a quick and sensitive method for measuring protein secretion is crucial. A fast and universal assay is most useful for detecting diverse proteins in a high-throughput manner. In this study, we introduce a split-luciferase-based method for measuring protein secretion by . The NanoBiT system was used to monitor secretion of four different proteins: xylanase A, amylase M, protein glutaminase A, and GFP nanobody. Our findings underscore the split-luciferase system as a quick, sensitive, and user-friendly method.