从风干香肠中分离得到一株生长良好的乳酸菌ORC4,菌株能产乳酸、革兰氏染色阳性、接触酶阴性。经系统发育分析,结合菌落形态、细胞形态、生化反应试验,确定菌株ORC4为绿色魏斯氏菌。绿色魏斯氏菌ORC4的完整和破碎细胞对O2-·、DPPH·和·OH的清除率都与细胞浓度呈正相关。在细胞浓度为5×108 CFU/mL时,菌株ORC4破碎细胞对O2-·、DPPH·和·OH的清除率都高于完整细胞,分别为45.17%、56.17%和54.01%。菌株ORC4还能清除培养基中最多为35.87 μg/mL的胆固醇,单位细胞干重的胆固醇清除率为19.89 μg/mg。
|
A Gram(＋),non-motile,facultatively anaerobic,rod-or coccoid-shaped bacterium,designated strain ORC4,was isolated from the dry fermented sausages. The 16S rRNA gene sequence analysis showed that strain ORC4 belonged to the genus Weissella,with highest sequence similarity to Weissella viridescens NRIC1536(100%). The intact cells and intracellular extract of strain ORC4 could inhibit O2-·,DPPH·,and ·OH. Three free radicals-scavenging ratios of intracellular extract were positively correlated with bacterial density,respectively,the intact cells could do the same. The intracellular extract had higher scavenging ratios on three free radicals than the intact cells. At a concentration of 5×108 CFU/mL,scavenging ratios of intracellular extract on O2-·,DPPH· and ·OH were 45.17%,56.17% and 54.01% respectively. In addition,strain ORC4 could reduce 35.87 μg/mL cholesterol,and the unit cell dry weight of cholesterol removal rate was 19.89 μg/mg.
|
