响应曲面法优化螺旋藻结合态胞外聚合物的提取

Optimization of Spirulina platensis bound extracellular polymeric substances extraction by response surface method

螺旋藻(Spirulina platensis)胞外聚合物(EPS)具有抗菌、抗氧化等多种生物特性,广泛应用于医学和工业等领域。本文探究超声温度、振幅百分比、超声时间等因素对钝顶螺旋藻结合态EPS(B-EPS)提取量的影响,采用响应曲面分析法中Box-Behnken设计法,获得3种因素的最佳组合,并以此条件提取B-EPS,分析其主要组分多糖、蛋白和核酸含量,并采用傅里叶红外光谱(FTIR)表征其官能团。结果表明,3种因素对B-EPS含量均有影响,超声温度的影响最大。模型预测得到的最优提取条件为:超声温度52.02℃,振幅百分比57.88%,超声时间6.91 min,在此条件下,B-EPS的多糖、蛋白和核酸含量分别为98.43±4.72、75.78±1.68和3.67±0.54 mg/gDW。FTIR结果表明,B-EPS含有蛋白质(C=O、C-N和N-H)、碳水化合物(C-O-C)、糖环类物质(-C-O)、含苯环类物质(C-H)等相关基团。本文结果为深入探讨螺旋藻EPS的抗逆功能奠定了基础。

Extracellular polymeric substances(EPS)of Spirulina platensis have many biological properties such as antibacterial and anti-oxidation,and have been widely applied in medicine and industry.In this paper,the effects of ultrasonic temperature,amplitude percentage and ultrasonic time on the extraction amount of bound EPS(B-EPS)in S.platensis were investigated.The optimal combination of three factors was obtained by Box-Behnken design method(BBD)in response surface method(RSM),and B-EPS were extracted to analyze their main components polysaccharide,protein and nucleic acid under this condition.The functional groups of B-EPS were characterized by fourier transform infrared spectroscopy(FTIR).The results showed that the three factors had positive effects on the B-EPS content,and the influence of the ultrasonic temperature was the most obvious.The optimal extraction conditions were as follows:ultrasonic temperature of 52.02℃,amplitude percentage of 57.88%,ultrasonic time of 6.91 min.Under this condition,the contents of polysaccharide,protein and nucleic acid were 98.43±4.72,75.78±1.68 and 3.67±0.54 mg/g DW,respectively.The results of FTIR indicated that the B-EPS contained functional groups related to proteins(C=O,C-N and N-H),carbohydrates(C-O-C),sugar rings(-C-O)and benzene ring-containing substances(C-H).The results of this paper may provide the foundation for further exploration of the stress resistance of S.platensis EPS.