2种不同来源的黑牛肝菌SOD酶活稳定性研究

本研究分别对野生种PH-16与栽培种PH-20黑牛肝菌进行SOD酶活稳定性研究,通过SOD酶对H2O2及乙醇-氯仿的化学敏感性差异,确定SOD酶类型,以没食子酸自氧化法测定酶活,通过温度、pH以及4℃保藏时间梯度对其SOD酶稳定性进行了探究.结果表明,硫酸铵-丙酮复合沉降法,SOD酶活性最高,PH-20菌丝体蛋白含量是PH-16的1.32倍,而PH-16 SOD比活力最高可达PH-20的1.42倍.两种黑牛肝菌SOD酶活性均对H2O2浓度变化敏感,对乙醇-氯仿浓度变化保持活性稳定,确定SOD酶类型为Cu,Zn-SOD酶.PH-16 SOD酶最高酶活条件为pH=5.5,温度25℃,活性平均衰退速率16.2 U·mL-1·d-1.PH-20 SOD酶最高酶活条件为pH=6.5,温度30℃,活性平均衰退速率8.5 U·mL-1·d-1.

Study on the Stability of SOD Activity of Phlebopus Portentous from Two Different Sources

The stability of SOD enzyme activity of wild species PH-16 and cultivated species PH-20 were studied in this paper,the type of SOD was identified by H₂O₂ and ethanol-chloroform methods,and the enzyme activity was determined by gallic acid autoxidation method.The stability of superoxide dismutase SOD of Phlebopus portentous was studied by temperature,pH and 4℃.The results showed that compared with acetone precipitation method,the recovery rate of mycelium protein and the SOD activity were higher.The protein content of PH-20 fermentation mycelium was 1.32 times of that of PH-16,but PH-16 SOD specific activity was 1.42 times more than PH-20.The SOD enzyme activities of the two kinds of Phlebopus portentous were both sensitive to the change of H₂O₂ concentration and remained stable to the change of ethanol-chloroform concentration.The SOD enzyme type was determined to be Cu,Zn-SOD enzyme.The results showed that the highest activity of PH-16 SOD was pH=5.5,temperature 25℃,and the average decline was 16.2 U·mL^-1·d^-1;the highest enzyme activity of PH-20 SOD was pH=6.5,temperature 30℃,and the average decline was 8.5 U·mL^-1·d^-1.