Library of Bacillus subtilis CRISPRi knockdown strains: sample of ICEBs1 donors collected prior to mating experiment
A library of B. subtilis strains was generated, wherein each strain each comprised a CRISPRi knockdown of a single essential B. subtilis gene as well as the integrative and conjugative element ICEBs1. Strains were induced to mate with an ICEBs1-lacking recipient strain. Prior to mating, this sample of the ICEBs1+ donors was collected. Genomic DNA was extracted using Qiagen DNeasy Blood and Tissue kits according to manufacturer instructions. A portion of the genomic locus encoding the 20 nt variable region of the single guide RNA was amplified by PCR (20 cycles) and purified via SureSelect AMPure beads according to manufacturer instructions. Indexed samples were pooled and sequenced with an Illumina MiSeq using a 20 bp read length using a custom sequencing primer.