链带藻Desmodesmus sp. QL96蛋白质的营养价值评价与生理活性研究

链带藻Desmodesmus sp. QL96是从我国西藏地区分离的一株链带藻,前期研究表明其含有丰富的蛋白质。本文对这株链带藻的主要细胞组分的含量进行了检测,并采用改进的TCA-丙酮法提取其蛋白质,分析了蛋白粗提物的氨基酸组成及其体外抗氧化和抑菌活性。结果表明：链带藻Desmodesmus. sp. QL96的蛋白质平均含量为(56.65±3.76)%,蛋白粗提物中含有17种氨基酸,其中7种人体必需氨基酸含量占总氨基酸含量的26.86%;Desmodesmus sp. QL96蛋白质具有一定的自由基清除能力,对?OH和DPPH?的半数清除浓度（IC₅₀）分别为0.18、7.88 mg/mL;Desmodesmus sp. QL96蛋白质具有一定的抑菌作用,对化脓性链球菌、大肠杆菌和鼠伤寒沙门氏菌的最小抑菌浓度（MIC）分别为1.56、3.13、1.56 mg/mL。本研究为该链带藻进一步开发功能性蛋白提供了依据与参考。

Evaluation of Desmodesmus sp. QL96 Protein on Nutritional Value and its Physiological Activitiy

Microalga Desmodesmus sp. QL96 was originally isolated from Tibet, China. Previous studies have shown that it is rich in protein. In this work, the primary cell compositions were determined, and proteins were extracted by the improved TCA-acetone method. The amino acid composition, antioxidant and antibacterial activity of the extracted proteins were analyzed. The results suggested that the mean protein content of the microalga was (56.65±3.76)%. The raw proteins were tested to contain 17 amino acids, including 7 essential amino acids which accounted for 26.86% of the total amino acids. The extracted proteins showed scavenging ability against free radical, with the half scavenging concentration (IC₅₀) of ?OH and DPPH? being 0.18 and 7.88 mg/mL, respectively. Also, an inhibition against bacteria was demonstrated by the raw protein, with the minimum inhibitory concentration against Streptococcus pyogenes, Escherichia coli and Salmonella typhimurium being 1.56, 3.13, 1.56 mg/mL, respectively. This study could provide a basis and reference for the further development of functional proteins of Desmodesmus sp. QL96.