The thnI gene is not required for thurincin H biosynthesis or immunity

Thurincin H is a bacteriocin produced by Bacillus thuringiensis, it is encoded in a group of ten genes, most of which have been characterized experimentally or by homology. However, the activity of the thnI gene encoding a 95 amino acid ORF remains unknown. In this work, the thnI gene was cloned under the regulation of two promoters and transformed into a sensitive strain to determine if it acts as an immunity protein. In addition, a deletion mutant without the thnI gene was used to test whether thnI is required or not for the biosynthesis of thurincin H. It was concluded that thnI does not provide immunity and is not required to produce thurincin H.