title: High-level expression of heme-dependent catalase gene katA from Lactobacillus Sakei protects Lactobacillus rhamnosus from oxidative stress.
abstract: Lactic acid bacteria (LAB) are generally sensitive to hydrogen peroxide (H(2)O(2)), Lactobacillus sakei YSI8 is one of the very few LAB strains able to degrade H(2)O(2) through the action of a heme-dependent catalase. Lactobacillus rhamnosus strains are very important probiotic starter cultures in meat product fermentation, but they are deficient in catalase. In this study, the effect of heterologous expression of L. sakei catalase gene katA in L. rhamnosus on its oxidative stress resistance was tested. The recombinant L. rhamnosus AS 1.2466 was able to decompose H(2)O(2) and the catalase activity reached 2.85 mumol H(2)O(2)/min/10(8) c.f.u. Furthermore, the expression of the katA gene in L. rhamnosus conferred enhanced oxidative resistance on the host. The survival ratios after short-term H(2)O(2) challenge were increased 600 and 10(4)-fold at exponential and stationary phase, respectively. Further, viable cells were 100-fold higher in long-term aerated cultures. Simulation experiment demonstrated that both growth and catalase activity of recombinant L. rhamnosus displayed high stability under environmental conditions similar to those encountered during sausage fermentation.
authors.affiliation: Key Laboratory of Functional Dairy of Ministry of Education of the People's Republic of China & Municipal Government of Beijing, College of Food Science & Nutritional Engineering, China Agricultural University, 17 Qing Hua East Road, Hai Dian District, Beijing 100083, China.
authors.forename: Haoran
authors.initials: H
authors.lastname: An
authors.forename: Hui
authors.initials: H
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Huang
authors.forename: Guohong
authors.initials: G
authors.lastname: Wang
authors.forename: Chunguang
authors.initials: C
authors.lastname: Luan
authors.forename: Jing
authors.initials: J
authors.lastname: Mou
authors.forename: Yunbo
authors.initials: Y
authors.lastname: Luo
authors.forename: Yanling
authors.initials: Y
authors.lastname: Hao
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005285:Fermentation; D005516:Food Microbiology; D006418:Heme / Q000378:metabolism; D006861:Hydrogen Peroxide; D007778:Lactobacillus / Q000201:enzymology* / Q000235:genetics; D052201:Lacticaseibacillus rhamnosus / Q000235:genetics / Q000378:metabolism*; D018384:Oxidative Stress / Q000502:physiology*; D010544:Peroxidases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D006418:Heme; D006861:Hydrogen Peroxide; D010544:Peroxidases; C081610:catalase-peroxidase, bacteria