School of Forestry, Northeast Forestry University, No. 26, Hexing Street, Harbin 150040, China.
Heilongjiang Weiliang Biological Technology Co., Ltd., No. 45, Yanxing Street, Harbin 150001, China.
Molecules. 2022 Apr 21;27(9):2664. doi: 10.3390/molecules27092664.
This study aimed to elucidate the responses of a novel characterized WJL-G4 against citric acid stress by performing physiological analysis, morphology observation, and structural and membrane fatty acid composition analysis. The results showed that under citric acid stress, the cell vitality of WJL-G4 was reduced. The cell morphology changed with the unclear, uncompleted and thinner cell wall, and degraded the cell structure. When the citric acid concentration was 20 g/L, WJL-G4 could tolerate citric acid and maintain the cell structure by increasing the intracellular pH, superoxide dismutase activity, and contents of unsaturated fatty acids. As the citric acid concentration was ≥80 g/L, the stress has exceeded the cellular anti-stress ability, causing substantial cell damage. The cell membrane permeability, the content of membrane lipids, malondialdehyde and superoxide anion increased, but the intracellular pH and superoxide dismutase activities decreased, accompanying the increase of citric acid concentrations. The findings of this work provided a theoretical basis for the responsive mechanism of WJL-G4 under high concentrations of citric acid, and can serve as a reference for biological acid reduction in fruit processing.
本研究通过生理分析、形态观察、结构和膜脂肪酸组成分析，阐明了新型 WJL-G4 对柠檬酸胁迫的响应。结果表明，在柠檬酸胁迫下，WJL-G4 的细胞活力降低。细胞形态发生变化，细胞壁不清晰、不完整且变薄，细胞结构降解。当柠檬酸浓度为 20 g/L 时，WJL-G4 可以通过增加细胞内 pH 值、超氧化物歧化酶活性和不饱和脂肪酸含量来耐受柠檬酸并维持细胞结构。当柠檬酸浓度≥80 g/L 时，胁迫超过了细胞的抗应激能力，导致大量细胞损伤。细胞膜通透性、膜脂含量、丙二醛和超氧阴离子增加，而细胞内 pH 值和超氧化物歧化酶活性降低，伴随柠檬酸浓度的增加。这项工作的结果为 WJL-G4 在高浓度柠檬酸下的响应机制提供了理论依据，并可为水果加工中的生物酸化提供参考。
