Abstract
The species Bacillus licheniformis includes important strains that are used in industrial production processes. Currently the physiological model used to adapt these processes is based on the closely related model organism B. subtilis. In this study we found that both organisms reveal significant differences in the regulation of subtilisin, their main natural protease and a product of industrial fermentation processes. We identified and characterized a novel antisense sRNA AprAs, which represents an RNA based repressor of apr, the gene encoding for the industrial relevant subtilisin protease. Reduction of the AprAs level leads to an enhanced proteolytic activity and an increase of Apr protein expression in the mutant strain. A vector based complementation of the AprAs deficient mutant confirmed this effect and demonstrated the necessity of cis transcription for full efficiency. A comparative analysis of the corresponding genome loci from B. licheniformis and B. subtilis revealed the absence of an aprAs promoter in B. subtilis and indicates that AprAs is a B. licheniformis species specific phenomenon. The discovery of AprAs is of great biotechnological interest since subtilisin Carlsberg is one of the main products of industrial fermentation by B. licheniformis.
Highlights
Bacillus licheniformis was originally isolated and described by Weigman in 18981
The RNA based regulatory network of B. licheniformis DSM13 was analysed by RNA-Seq using samples from different stages of an industrial fermentation[25].The transcriptome data revealed a considerable number of protein encoding RNAs and 3,314 non-coding RNAs, divided in 2853 mRNA-bound and 461 small RNAs
In the transcriptome of B. licheniformis an antisense RNA element on the 3′ end of the apr gene, encoding the subtilisin protease, gained considerable attention, since the samples were taken from a subtilisin fermentation[25]
Summary
Bacillus licheniformis was originally isolated and described by Weigman in 18981. The species is a member of the B. subtilis species complex[2] and exhibits a saprophytic life style on organic material[3, 4]. The RNA based regulatory network of B. licheniformis DSM13 was analysed by RNA-Seq using samples from different stages of an industrial fermentation[25].The transcriptome data revealed a considerable number of protein encoding RNAs and 3,314 non-coding RNAs, divided in 2853 mRNA-bound and 461 small RNAs. In general, small RNAs (sRNA) are versatile regulators of gene expression, which can facilitate their function in cis or trans, controlling e.g. mRNA stability, degradation, termination and translation[26, 27]. In the transcriptome of B. licheniformis an antisense RNA element on the 3′ end of the apr gene, encoding the subtilisin protease, gained considerable attention, since the samples were taken from a subtilisin fermentation[25]. The association of the apr gene with a highly expressed small antisense RNA indicates an additional regulatory layer in B. licheniformis. By inactivation of the aprAs promoter and vector encoded transcription of AprAs we could show its regulatory effect on proteolytic activity and Apr expression
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
