CRISPR-Cas9-mediated Large Cluster Deletion and Multiplex Genome Editing in Paenibacillus polymyxa

The use of molecular tools based on the clustered regularly interspaced short palindromic repeats-Cas (CRISPR-Cas) systems has rapidly advanced genetic engineering. These molecular biological tools have been applied for different genetic engineering purposes in multiple organisms, including the quite rarely explored Paenibacillus polymyxa. However, only limited studies on large cluster deletion and multiplex genome editing have been described for this highly interesting and versatile bacterium. Here, we demonstrate the utilization of a Cas9-based system to realize targeted deletions of four biosynthetic gene clusters in the range of 12 kb to 41 kb by the use of a single targeting sgRNA. Furthermore, we also harness the system for multiplex editing of genes and large genomic regions. Multiplex deletion was achieved with more than 80 % efficiency, while simultaneous integration at two distantly located sites was obtained with 58 % efficiency. The findings reported in this study are anticipated to accelerate future research in P. polymyxa and related species.