['In Gram-positive bacteria, signal peptide-bearing secretory proteins are translocated through the cytoplasmic membrane and fold into their native conformation on the outside of the cell. The products of the Bacillus subtilis wprA and dltB genes separately influence post-translocational stages of the secretion process by mediating proteolytic degradation and folding of secretory proteins. Inactivation of either wprA or dltB in B. subtilis increases the yield of secretory proteins released into the culture medium in an intact and biologically active conformation. The aim of this work was to study the combined influence of these genes.', 'A wprA/dltB double mutant was constructed, but did not have an additive effect on secretion and caused a significant reduction in the yield of alpha-amylase.'] Does simultaneous inactivation of the wprA and dltB genes of Bacillus subtilis reduce the yield of alpha-amylase?