LAUSR

ObjectiveTo investigate the aerotolerance of Lactobacillus rhamnosus hsryfm 1301 and its influencing factors.ResultsThe growth rate of L. rhamnosus hsryfm 1301 weakened noticeably when the concentration of supplemented H2O2 reached 1 mM, and only 2% of all L. rhamnosus hsryfm 1301 cells survived in MRS broth supplemented with 2 mM H2O2 for 1 h. After pretreatment with 0.5 mM H2O2, the surviving cells of L. rhamnosus hsryfm 1301 in the presence of 5 mM H2O2 for 1 h increased from 3.7 to 7.8 log CFU. Acid stress, osmotic stress, and heat stress at 46 °C also enhanced its aerotolerance, while heat stress at 50 °C reduced the tolerance of L. rhamnosus hsryfm 1301 to oxidative stress. Moreover, treatment with 0.5 mM H2O2 increased the heat stress tolerance of L. rhamnosus hsryfm 1301 by approximately 150-fold.ConclusionsLactobacillus rhamnosus hsryfm 1301 possesses a stress-inducible defense system against oxidative stress, and the cross-adaptation to different stresses is a promising target to increase the stress tolerance of L. rhamnosus hsryfm 1301 during probiotic food and starter culture production.