New method for gene disruption in Salmonella typhimurium: construction and characterization of an ada-deletion derivative of Salmonella typhimurium TA1535

An AdaST-deletion mutant derivative of Salmonella typhimurium TA1535 is constructed by a new method for gene disruption in Salmonella typhimurium. A kanamycin resistance gene takes the place of the resident ada-like gene, and this forms an AdaST-deletion mutant derivative. AdaST played the role of a transcriptional activator and protects the cells from being killed. The new method for gene disruption involves the use of T4 DNA ligase to treat the linearized DNA bits which do not originate from DNA replication.