Inactivation of the conserved protease LonA increases production of xylanase and amylase in Bacillus subtilis

In a previous study we used RNA-seq to identify cellular stresses related to the overexpression of xylanase XynA, and found that upregulation of the CtsR regulon improves the yield of XynA production in B. subtilis. In this study, we compared the transcriptomes of B. subtilis cells overexpressing either the xylanase XynA or the heterologous amylase AmyM, to identify general and enzyme-specific stress responses. In addition, we further compared the translational profiles of cells overexpressing XynA and AmyM using ribosome profiling. Overexpression of XynA and AmyM was achieved by cloning xynA and amyM respectively in the multicopy expression plasmid pUB110 behind the strong amyQ promoter. As a negative control, we transformed cells with an empty plasmid (Emp). The strains were grown in nutrient-rich LB medium at 37 °C in the presence of 50 μg/ml kanamycin to maintain the plasmids. We sampled cells at 3 h (OD600~0.8) and 6h growth (OD~4) and performed RNA-seq and Ribome profiling. We compared the transcriptomes and translation profiles between XynA and AmyM overproducing cells. Two independent biological replicates were performed.