Zhang Huan, Xu Jianhang, Chen Qian, Wang Hui, Kong Baohua
College of Food Science, Northeast Agricultural University, Harbin 150030, China.
Foods. 2021 May 26;10(6):1203. doi: 10.3390/foods10061203.
As functional starter cultures and potential probiotics, the ability of lactic acid bacteria to resist oxidative stress is essential to maintain viability and functional properties. This study investigates the effects of HO at different concentrations (0, 1, 2, and 3 mM) on the physiological, morphological, and antioxidant properties of R1 and R6 isolated from Harbin dry sausages. The increase in HO concentration induced a significant increase in reactive oxygen species and a decrease in intracellular ATP levels ( < 0.05). Based on scanning electron microscopy, transmission electron microscopy, and electric conductivity analysis, HO stress caused cell deformation, the destruction of cell membrane integrity, partial loss of the cytoplasm, and an increase in the cell conductivity of both strains. HO stress with 1 mM or 2 mM concentrations could effectively improve the scavenging rates of free radicals, the activities of superoxide dismutase and glutathione peroxide, and the total antioxidant capacity of both strains ( < 0.05). In conclusion, an appropriate oxidative stress contributed to the activation of the antioxidant defense system of both strains, conferred strains a better effect in inhibiting the oxidation of fermented foods, and improved the health of the host.
作为功能性发酵剂和潜在的益生菌，乳酸菌抵抗氧化应激的能力对于维持其活力和功能特性至关重要。本研究调查了不同浓度（0、1、2和3 mM）的过氧化氢（HO）对从哈尔滨干香肠中分离出的R1和R6的生理、形态和抗氧化特性的影响。HO浓度的增加导致活性氧显著增加，细胞内ATP水平降低（P<0.05）。基于扫描电子显微镜、透射电子显微镜和电导率分析，HO胁迫导致细胞变形、细胞膜完整性破坏、细胞质部分丧失以及两株菌的细胞电导率增加。1 mM或2 mM浓度的HO胁迫可有效提高两株菌的自由基清除率、超氧化物歧化酶和谷胱甘肽过氧化物酶活性以及总抗氧化能力（P<0.05）。总之，适当的氧化应激有助于激活两株菌的抗氧化防御系统，使菌株在抑制发酵食品氧化方面具有更好的效果，并改善宿主健康。
