Recent genome mining studies have demonstrated that unexplored habitats hold significant potential for discovering novel nonribosomal peptides (NRPs) and ribosomally synthesized and post-translationally modified peptides (RiPPs). Lanthipeptides are a class of RiPPs that contain lanthionine and methyllanthionine cross-links. These modifications give lanthipeptides unique structural stability and bioactivity, often resulting in potent antimicrobial properties [1-2].
Paenibacillus sp. 23TSA30-6 is an endospore-forming strain isolated from the deep oligotrophic Krubera-Voronja Cave. This strain is highly active against both Gram-positive and Gram-negative bacteria and was shown to encode 21 biosynthetic gene clusters (BGCs). One of these BGC code for a RiPP that belong to class II lanthipeptides [3]. The goal of this work is to produce class II lanthipeptide of 23TSA30-6 strain heterologously in Lactoccocus lactis and to determine its antibacterial activity.
For this purpose, genes of predicted BGC, responsible for synthesis of class II lanthipeptide (LanT, LanA, LanM) were cloned into the L. lactis expression vector, pNZ8048. The resulting plasmid were transferred to L. lactis cells by electroporation. The recombinant gene expression was tested by determining the antimicrobial activity against Gram-positive and Gram-negative bacteria. After determining its activity, the peptide will be later purified and characterised. Initial observations indicate that expression in L. lactis may support the production of a class II lanthipeptide, with further studies required to determine its properties and activity.
In conclusion, this study aimed to heterologously express the class II lanthipeptide and to determine its antimicrobial activity (separately from other bioactive compounds secreted by Paenibacillus sp. 23TSA30-6). The obtained results will contribute to discovering novel antimicrobials, which could be applied in the development of new therapeutic agents.