天然抗冻多肽的性质与对乳酸菌的低温胁迫保护作用

Studies on the Properties and Hypothermia Protection Activities of Antifreeze Peptides

目的:分析猪皮明胶抗冻多肽的相关性质,研究其对乳酸菌的低温胁迫保护活性。方法:应用ANS荧光探针法测定抗冻多肽表面疏水性;应用差示扫描量热法测定抗冻多肽热滞活性;应用偏光显微镜观察低温循环过程中抗冻多肽对冰晶的重结晶抑制活性;平板菌落计数法检测低温冷冻后乳酸菌的存活率。结果:在最优条件下获得的抗冻多肽其水解度为7.2%,抗冻多肽中80%的组分分子质量分布在150～2 000 u。表面疏水性值363,等电点为3.93,热滞活性为0.58℃,有显著的重结晶抑制活性。乳酸菌低温冷冻结果表明,1%添加量的抗冻多肽,可显著提高乳酸菌存活率。

Objective： Analysis the relative properties of antifreeze peptides from pigskin gelatin and studying the hypothermia protection activity on the lactic acid bacteria. Method： The ANS fluorescent probe method was employed to determine the surface hydrophobicity of antifreeze peptides; The differential scanning calorimetry（DSC） was employed to determine the thermal hysteresis activity; Application of polarized light microscope was used to observe the recrystallization inhibition activity of antifreeze polypeptide; Detecting the survival rates of lactic acid bacteria via the plate colony count method after frozen. Results： the DH of antifreeze polypeptide was 7.2% under the optimal conditions, and 80% of the components of antifreeze polypeptide with the molecular mass distribution among 150-2 000 u. The surface hydrophobicity value of antifreeze polypeptide was 363, the isoelectric point was 3.93, and the thermal hysteresis activity was0.58 ℃, respectively. In addition, the antifreeze peptides showed a significant recrystallization inhibition activity. The result of lactic acid bacteria frozen at low temperature was shown that antifreeze peptides provide a well protection for the lactic acid bacteria at a concentration of 1%.