一株耐高温SOD产生菌的筛选及酶学特性

SCREENING OF THERMOPfflLIC SUPEROXIDE DISMATASE PRODUCING STRAIN AND SOME PROPERTIES OF THE ENZYME

超氧化物歧化酶(Superoxide dismutase简称SOD)是生物体防御氧化损伤的金属酶。具有治疗炎症、抗辐射损伤、防癌、抗衰老等广泛药用前景。另外在植物抗逆和生物固氮等方面也有重要作用。自1969年McCord和Fridovich发现该酶以来,人们已从多种动植物和微生物中分离了此酶。SOD的基因工程也取得了令人瞩目的成就。相对而言,动植物Cu、Zn-SOD的研究较活跃,而微生物SOD,特别是Fe-SOD的研究较薄弱。本文报道耐高温SOD产生菌的筛选、鉴定结果,并对酶的稳定性和酶学特性作了研究。

A thermophilic SOD producing strain was obtained from the bacteria preserved in our lab. Its content of SOD was 8774u / g fresh cells. The strain can tolerate 0.4% I^Oj and 70 癈, and it has outstanding culture characteristics. It was identified as Bacillus stearothermophilus, called B.S 211-15. Crude SOD was extracted from B.S 211-15, the recovery of total activity was 69.5%, the specific activity was 1793u / mg protein. The enzyme showed fine heat stability, pH stability and good proteinase resistance. The SOD activity didn' t decrease after being kept in room temperature for 2 months. The results of inhibition reactions indicated that this enzyme was Fe-SOD.