Yu Shu-Chuan, Fen Shin-yuan, Chien Cheng-Lun, Wong Hin-chung
Department of Microbiology, Soochow University, Taipei, Taiwan 111, Republic of China.
Department of Microbiology, Soochow University, Taipei, Taiwan 111, Republic of China
FEMS Microbiol Lett. 2016 Mar;363(6). doi: 10.1093/femsle/fnw038. Epub 2016 Feb 17.
The marine foodborne enteropathogen, Vibrio parahaemolyticus, has four putative catalase genes. Function of the katG-homologous genes, katG1(VPA0768) and katG2(VPA0453), was examined using gene deletion mutants, and compared with those of the katE-homologous genes, katE1(VPA1418) and katE2(VPA0305). Bacterial growth of ΔkatG1 was significantly delayed in the presence of 200-300 μM H2O2, and such inhibition was enhanced when incubation temperature was lowered from 37°C to 22°C. In the stationary phase, the ΔkatG1 strain was more susceptible to the lethal dosage of H2O2 than the ΔkatE1 strain. The minimum inhibitory concentrations and minimum bactericidal concentrations revealed that ΔkatE1/ΔkatE2 strains were more susceptible to H2O2 than the ΔkatG1/ΔkatG2 strains in exponential phase, while ΔkatG1 was more susceptible than the ΔkatE1/ΔkatE2 strains in the starved culture. This study demonstrated the chief antioxidative role of katG1 in the stationary phase and starved culture of V. parahaemolyticus, while katG1 and katG2 were also responsive to H2O2 and cumene hydroperoxide in the exponential phase.
海洋食源性病原体副溶血性弧菌有四个假定的过氧化氢酶基因。利用基因缺失突变体研究了与katG同源的基因katG1（VPA0768）和katG2（VPA0453）的功能，并与与katE同源的基因katE1（VPA1418）和katE2（VPA0305）的功能进行了比较。在200 - 300μM过氧化氢存在的情况下，ΔkatG1的细菌生长显著延迟，并且当培养温度从37°C降至22°C时，这种抑制作用增强。在稳定期，ΔkatG1菌株比ΔkatE1菌株对致死剂量的过氧化氢更敏感。最低抑菌浓度和最低杀菌浓度表明，在指数生长期，ΔkatE1/ΔkatE2菌株比ΔkatG1/ΔkatG2菌株对过氧化氢更敏感，而在饥饿培养中，ΔkatG1比ΔkatE1/ΔkatE2菌株更敏感。本研究证明了katG1在副溶血性弧菌的稳定期和饥饿培养中的主要抗氧化作用，而katG1和katG2在指数生长期也对过氧化氢和氢过氧化异丙苯有反应。
