目的 研究乙酰化/去乙酰化酶Pat/CobB对沙门菌酸耐受应答的影响。方法 利用λ-Red同源重组系统分别敲除鼠伤寒沙门菌乙酰化酶/去乙酰化酶编码基因pat和cobB。利用生长曲线比较生长差异；Real-Time PCR检测参与酸应激的部分基因转录变化；采用Cfu计数法检验敲除株和野生株在对数期和平台期酸耐受应答中的差异。结果 成功构建了鼠伤寒沙门菌pat和cobB敲除株。pat和cobB敲除不影响细菌生长，也不影响对数期和平台期的鼠伤寒沙门菌对酸的耐受应答能力。结论 鼠伤寒沙门菌中编码乙酰化/去乙酰化酶的基因pat/cobB突变不会影响菌的生长，也不参与酸耐受应答。

Objective To investigate the effect of acetyltransferase/deacetylase Pat/CobB on the acid tolerance response (ATR) of Salmonella typhimurium. Methods The pat gene and cobB gene of Salmonella Typhimurium, which encode acetyltransferase and deacetylase, were deleted by the λ-Red system. The growth differences were compared through the growth curves. The transcriptional levels of some genes involved in acid stress were detected by Real-Time PCR. The differences of acid tolerance response between deletion mutants and wild type strains both at the log phase and at the stationary phase were examined by the colony forming units (Cfu) counting. Results The deletion mutants of pat and cobB of Salmonella typhimurium were successfully constructed. The deletion of pat and cobB did not affect the growth of Salmonella Typhimurium and the acid tolerance response both at the log phase and at the stationary phase. Conclusion The pat/cob genes of Salmonella Typhimurium encode the acetylase/deacetylase. The mutation of pat/cob genes will not affect the growth of bacteria and will not involve in the acid tolerance response.