We constructed the plasmid-based temperature sensitive allele of the essential gene PA0006 in P. aeruginosa PAO1. A suppressor sup mutant was isolated from spontaneous mutations that bypasses the lethality of PA0006 disruption. Genome re-sequencing indicated that the sup mutant contained multiple sizes of mutations. Interestingly, mutations appeared to enriched at the regulatory regions, suggesting a potential for suppression through transcription alterations. For this reason, comparative transcriptomic profiling between wild type, ts-allele, and sup is performed.